Secure two-way network connection system between private networks

Abstract

A secure private network connectivity service (SNCS) within a cloud service provider infrastructure (CSPI) is described that provides secure private network connectivity between external resources residing within a customer's on-premise environment and the customer's resources residing within the cloud. The SNCS provides secure private bidirectional network connectivity between external resources residing within a customer's external site representation and resources and services residing within the customer's VCN within the cloud without the need for an enterprise user (e.g., administrator) to explicitly configure the external resources, advertise routes, or set up site-to-site network connectivity. The SNCS provides high performance, scalable, and highly available site-to-site network connectivity for handling network traffic between the customer's on-premise environment and the CSPI by implementing a robust infrastructure of network elements and computing nodes that are used to provide the secure site-to-site network connectivity.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a PCT application of U.S. Non-Provisional Patent Application No. 17 / 515,093, entitled "Secure Bi-Directional Network Connectivity System between Private Networks," filed on October 29, 2021, and claims the benefit of and priority under 35 U.S.C. § 119(e), the contents of which are incorporated herein by reference in their entirety for all purposes.

[0002] This application is related to U.S. patent application Ser. No. 17 / 515,087, filed October 29, 2021, entitled "Transparent mounting of external endpoints between private networks," the contents of which are incorporated by reference into this specification for all purposes.

[0003] Technical Field The present disclosure relates generally to cloud-based services. More particularly, but by no means limited thereto, the present disclosure describes a secure private network connectivity service within a cloud infrastructure that includes improved functionality for establishing secure, private, bidirectional network connectivity between external resources residing within a customer's on-premise environment and the customer's resources residing within the cloud. [Background technology]

[0004] background The demand for cloud-based services continues to grow at a rapid rate. The term cloud services is generally used to refer to services made available to users or customers on demand (e.g., via a subscription model) using systems and infrastructure (cloud infrastructure) provided by a cloud service provider. Typically, the servers and systems that make up the cloud service provider's infrastructure are separate from the customer's own on-premise servers and systems. Thus, customers can utilize the cloud services provided by the cloud service provider without having to purchase separate hardware and software resources for the service. There are various different types of cloud services, including Software as a Service (SaaS), Platform as a Service (PaaS), Infrastructure as a Service (IaaS), etc. Summary of the Invention [Problem to be solved by the invention]

[0005] To take advantage of the many benefits offered by cloud services, enterprises are often required to move on-premise applications and data from their local data centres to public cloud infrastructures. This process typically requires enterprises to set up site-to-site network connections to establish secure connections between the enterprise's on-premise data centres and the cloud infrastructure. Configuring high-performance, scalable and highly available site-to-site network connections to handle network traffic between different networks can be a complex and time-consuming task for enterprises, especially when the enterprise's on-premise applications and data scale across multiple different networks.

[0006] A quick overview The present disclosure relates generally to cloud-based services. More particularly, but by no means limited thereto, the present disclosure describes a secure private network connectivity service within a cloud infrastructure that includes improved functionality for establishing secure, private, bidirectional network connectivity between external resources residing within a customer's on-premise environment and the customer's resources residing within the cloud. [Means for solving the problem]

[0007] In an embodiment, a secure network connection system is disclosed. The secure network connection service enables secure private network connectivity between an on-premises network associated with a customer of a cloud service provider and a virtual cloud network (VCN) hosted by the cloud service provider for the customer. The secure network connection system comprises a virtual overlay network including a set of one or more computing nodes. The system registers an external resource present in the on-premises network as an external endpoint in the virtual cloud network. The external endpoint is identified by an Internet Protocol (IP) address in the virtual cloud network. A first computing node of the set of computing nodes in the system creates an external resource representation of the external endpoint in the virtual cloud network. The external resource representation is created by creating a virtual network interface card (VNIC) and assigning an Internet Protocol (IP) address associated with the external endpoint to the VNIC. The first computing node then sends configuration information corresponding to the VNIC of the external resource representation to an agent configured in the on-premises network associated with the customer.

[0008] In one example, a second computing node of a set of computing nodes in the system receives a request to query information associated with a resource residing in a VCN associated with a customer. The query is sent by an external resource residing in an on-premises network. In one embodiment, the external resource is provisioned with a logical interface. The second computing node establishes a connection between the logical interface provisioned to the external resource residing in the on-premises network and a VNIC created for a representation of the external resource in the virtual cloud network. The second computing node sends the request to the resource residing in the virtual cloud network via the established connection and obtains a result corresponding to the request via the established connection.

[0009] In one embodiment, an agent in an on-premise network is configured to establish a secure virtual private network (VPN) connection between an external resource present in the on-premise network and a set of one or more computing nodes comprising a secure network connectivity system. In one example, the agent is configured to provision a logical interface for the external resource present in the on-premise network based at least in part on configuration information corresponding to a VNIC of the external resource representation. In one example, provisioning the logical interface for the external resource includes assigning, by the agent, a virtual Internet Protocol (IP) address of a virtual network interface card (VNIC) of the external resource representation to the logical interface.

[0010] In one example, the configuration information corresponding to a VNIC in the external resource representation includes a virtual Internet Protocol (IP) address of the VNIC, a fully qualified domain name associated with the computing instance associated with the VNIC, and a cloud identifier of a virtual cloud network associated with the customer.

[0011] In one example, the second computing node establishes a connection between a logical interface provisioned to an external resource present in the on-premises network and a virtual network interface card created for a representation of the external resource in the virtual cloud network via an agent present in the on-premises network.

[0012] In one example, the second computing node sends a request to a resource residing in the virtual cloud network via the established connection, the process including translating, by the second computing node, a physical IP address associated with the external resource to a virtual IP address associated with a VNIC of a representation of the external resource in the virtual cloud network associated with the customer, and sending the request to the virtual IP address associated with the VNIC.

[0013] In one example, the secure network connection system enables creation of an external site representation of an on-premise network associated with a customer. The external site representation is a logical representation of the on-premise network and is identified by an external site identifier and a customer identifier. In one example, external resources are registered within the external site representation.

[0014] In one example, a second computing node in the secure network connection system establishes a connection between a logical interface provisioned to an external resource present in the external site representation and a virtual network interface card created for the external resource representation in the virtual cloud network. In one example, the external resource is a database, application, or compute instance present in the on-premise network.

[0015] Various embodiments are described herein, including methods, systems, non-transitory computer-readable storage media storing programs, codes, or instructions executable by one or more processors, and the like. These exemplary embodiments are mentioned not to limit or define the present disclosure, but to provide examples to aid in its understanding. Additional embodiments are discussed in the detailed description, and further description is provided therein. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 illustrates a distributed environment 100 including a secure private network connectivity service within a cloud service provider infrastructure (CSPI), according to an embodiment. [Diagram 2] FIG. 2 illustrates additional details of the operations performed by the systems and subsystems shown in FIG. 1 to provide secure, private network connectivity between a customer's external resources residing in the customer's on-premises network and resources and services residing in the customer's VCN, in accordance with an embodiment. [Diagram 3] 2 illustrates an example of a process performed by the system and subsystems shown in FIG. 1 to provide secure private network connectivity, according to an embodiment. [Figure 4] 1 is a flowchart illustrating the flow of network packets between an external resource residing in a customer's on-premise network and an external resource in the customer's virtual cloud network, according to one embodiment. [Diagram 5] 1 is a flowchart illustrating the flow of network packets between an external resource representation in a customer's virtual cloud network and an external resource residing in the customer's on-premise network, according to one embodiment. [Figure 6] FIG. 1 is a high-level diagram of a distributed environment illustrating a virtual or overlay cloud network hosted by a cloud service provider infrastructure according to an embodiment. [Figure 7] FIG. 2 is a simplified architectural diagram of physical components in a physical network within a CSPI according to one embodiment. [Figure 8] FIG. 1 illustrates an exemplary configuration within CSPI in which a host machine is connected to multiple network virtualization devices (NVDs), according to one embodiment. [Figure 9] A diagram illustrating connections between host machines and NVDs to provide I / O virtualization to support multi-tenancy functionality in one embodiment. [Figure 10] FIG. 2 is a simplified block diagram of a physical network provided by CSPI according to one embodiment. [Figure 11] FIG. 1 is a block diagram illustrating one pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. [Figure 12] FIG. 1 is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. [Figure 13] FIG. 1 is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. [Figure 14] FIG. 1 is a block diagram illustrating another pattern for implementing a cloud infrastructure as a service system, according to at least one embodiment. [Figure 15] FIG. 1 is a block diagram illustrating an exemplary computer system in accordance with at least one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Detailed Description In the following description, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of certain embodiments. It will be apparent, however, that various embodiments may be practiced without these specific details. The drawings and description are not intended to be limiting. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or design described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other embodiments or designs.

[0018] The present disclosure relates generally to cloud-based services. More particularly, but by no means limited thereto, the present disclosure describes a secure private network connectivity service within a cloud infrastructure that includes improved functionality for establishing secure, private, bidirectional network connectivity between external resources residing within a customer's on-premise environment and the customer's resources residing within the cloud.

[0019] Cloud infrastructure can provide high performance compute, storage, and network capabilities in a flexible overlay virtual network that runs on top of a physical underlay network and is securely accessible from an enterprise's on-premises network. Cloud infrastructure allows an enterprise to manage its cloud-based workloads in the same way that it manages its on-premises workloads. Thus, an enterprise can obtain all the benefits of the cloud with the same control, isolation, security, and predictable performance as its on-premises network. An enterprise can build its own network using the compute, memory, and networking resources provided by the cloud. For example, a customer can build one or more customizable private networks, referred to as virtual cloud networks (VCNs), using resources provided by the cloud. On these customer VCNs, the customer can deploy one or more customer resources, such as compute instances. The compute instances can take the form of virtual machines, bare metal instances, etc. Thus, the cloud provides an infrastructure and a set of complementary cloud services that enable enterprises (customers) to build and run diverse applications and services in a highly available hosted environment.

[0020] To take advantage of the many benefits offered by cloud infrastructure, many enterprises perform migration of on-premise applications and data from the enterprise's local data centre to public cloud infrastructure. Moving workloads from an enterprise's local (i.e., on-premise) data centre to the cloud can be a complex and challenging process. Common challenges encountered during cloud migration include identifying the type of migration to perform, the type of resources that need to be moved, and the data dependencies between the resources by the enterprise. While moving workloads, some resources (e.g., databases, applications, etc.) may need to remain in the on-premise data centre for a period of time until they can be successfully moved to the cloud. Certain resources (e.g., business-critical resources, resources with data portability constraints, or resources with strict geographic requirements) may be identified as resources that will not be moved to the cloud and will remain in the on-premise data centre due to security reasons. To enable an enterprise to access on-premise resources from its VCN (within the cloud) and to enable resources residing in the on-premise data centre to securely access resources residing in the cloud, a secure private network connection needs to be established between the customer's (enterprise's) on-premise data centre and the customer's VCN. Setting up a secure site-to-site network connection can be a complex and time-consuming task for an enterprise, which typically requires network policy level management by an enterprise user (e.g., administrator) to set up the site-to-site network (e.g., VPN) connection, including setting up multiple configuration parameters and setting up VPN components (e.g., customer gateway device, target gateway device) of the site-to-site network connection.

[0021] Additionally, to access remote assets (e.g., on-premise resources such as databases or applications) residing in the on-premise data centre from the VCN using the site-to-site network connection, or to enable the remote assets residing in the on-premise data centre to securely access resources and services in the customer's VCN, the enterprise's user needs to perform additional tasks, such as manually configuring the gateway device to perform route advertisement and network address translation so that a secure connection between the remote assets in the customer's external environment and the resources in the customer's VCN can be achieved. The user also needs to manually configure the remote assets for traffic (e.g., network packets) to reach the remote assets from the customer's VCN and vice versa, configure route tables to include routes used by the site-to-site VPN connection, enable route propagation so that the route tables automatically propagate the site-to-site VPN routes, update security rules, etc.

[0022] In one embodiment, a secure private network connectivity service within a cloud service provider infrastructure (CSPI) is described that includes improved capabilities for establishing secure, private, bidirectional network connectivity between external resources residing within a customer's on-premise environment and the customer's resources residing within the cloud. The secure private network connectivity service is implemented using a secure network connectivity system (SNCS) within the cloud service provider infrastructure (CSPI). The SNCS described in this disclosure provides several technical advantages and / or improvements over traditional cloud-based network connectivity services. Using the novel and improved architecture of the present disclosure implemented by the SNCS, secure, private, bidirectional network connectivity between external resources residing within a customer's external site representation and resources and services residing within the customer's VCN in the cloud can be achieved without the need for an enterprise user (e.g., administrator) to explicitly configure the external resources, advertise routes, or set up site-to-site network connectivity. The SNCS provides high-performance, scalable, and highly available site-to-site network connectivity for handling network traffic between the customer's on-premise environment and the CSPI by implementing a robust infrastructure of network elements and computing nodes that are used to provide the secure site-to-site network connectivity. By using the robust infrastructure of network elements and computing nodes implemented by the SNCS, an enterprise's users can securely access its external resources from the cloud as if they were connecting to any other native resource in its VCN. Additionally, the SNCS enables one or more external resources that reside in the customer's on-premise network to securely reach out and access resources and services that reside in the customer's VCN (i.e., the cloud).Secure, private, bidirectional network connectivity between external resources within a customer's external site representation and resources and services that reside within the customer's VCN in the cloud can be achieved without the need for enterprise users (e.g., administrators) to explicitly configure the external resources, advertise routes, or set up site-to-site network connectivity.

[0023] Referring now to the drawings, FIG. 1 illustrates a distributed environment 100 including secure private network connectivity services in a cloud service provider infrastructure (CSPI), according to an embodiment. The distributed environment 100 includes multiple systems communicatively coupled to one another via one or more communication networks. These communication networks may include public and private networks. The distributed environment 100 illustrated in FIG. 1 is illustrative only and is not intended to unduly limit the scope of the claimed embodiments. Many variations, substitutions, and modifications are possible. For example, in some other embodiments, the distributed environment illustrated in FIG. 1 may have more or fewer systems or components than those illustrated in FIG. 1, may combine two or more systems, or may have a different configuration or arrangement of systems.

[0024] As shown in the example illustrated in FIG. 1, the distributed environment 100 includes a CSPI 102 that provides services and resources to which a customer can subscribe. In one embodiment, the CSPI 102 provides a secure private network connectivity service that includes functionality for providing a secure bidirectional private network between a customer's on-premise network and the customer's VCN hosted by the CSPI 102. In the example illustrated in FIG. 1, the secure private network connectivity service can be implemented by a secure network connectivity system (SNCS) 104 in the CSPI 102. The secure private network connectivity service provided by the SNCS 104 enables one or more resources (also referred to herein as external resources or remote assets) that reside within the customer's on-premise network to securely access resources and services that reside within the customer's VCN. The secure private network connectivity service provided by the SNCS 104 additionally enables resources and services in the customer's VCN to securely access external resources that reside in the customer's on-premise network. The customer can access external resources from within the customer's VCN as if they were connected to any other native resource that resides within that VCN. Secure access between on-premise external resources and resources residing in the customer's VCN (i.e., the cloud) can be enabled without requiring the customer (e.g., an enterprise user) to set up intricate site-to-site network connections between its on-premise network and the cloud, without the customer having to make any changes to its external resources, or without the customer having to configure the routes used by the site-to-site connections. Additional details of the processing performed by SNCS 104 to enable secure bidirectional connections between external resources residing in the customer's on-premise network and the customer's resources and services in the cloud are described in more detail below.

[0025] In one approach, secure bidirectional connectivity between external resources residing in a customer's on-premise network and the customer's resources and services in the cloud (e.g., customer's VCN) is achieved by the SNCS 104 using a multi-step process. In a first step, a user (e.g., an administrator) associated with the customer can create an "external site representation" 106 of the customer's on-premise network. For example, the user can interact with the SNCS 104 via a console user interface (UI) 108 of an application executed by the user device, via an API, or via a command line interface (CLI) executed by the user's device to create the external site representation 106. The external site representation (e.g., 106) can represent a logical or virtual representation of the customer's external site (e.g., on-premise network / on-premise data center) and can be identified by an external site identifier and a tenant (customer) identifier. As an example, the external site representation 106 can represent a high-level container resource that logically represents a portion of the customer's on-premise network and a subset of one or more external resources residing in the on-premise network.

[0026] In a second phase, the user downloads the agent 112 and installs / configures the agent 112 within the external site representation 106. In one embodiment, the agent 112 may be a software application downloaded by the user as part of a download package provided by the SNCS 104 when the user subscribes to a secure private connectivity service provided by the SNCS 104. The agent 112 may be installed and configured by the user within the external site representation 106 via the console UI 108.

[0027] In a third phase, upon successful installation of the agent 112 in the external site representation 106, the SNCS 104 authenticates the agent 112 and directs the setup of the customer's tenant-specific overlay network 128. The tenant-specific overlay network 128 may represent a virtual overlay network built on top of a physical network by the SNCS 104 for each tenant (customer) subscribing to services provided by the SNCS. The tenant-specific overlay network 128 is used to establish a secure private network connection between the customer's external site representation 106 and the customer's VCN 148 in the CSPI. As shown in the embodiment illustrated in FIG. 1, the tenant-specific overlay network 128 may include a distributed, horizontally scalable fleet of computing nodes including a set of one or more tunnel hosts (also referred to herein as tunnel virtual machines), tunnel VM-1 116 and tunnel VM-2 122, and a set of one or more resource hosts (also referred to herein as resource virtual machines), resource VM-1 130 and resource VM-2 132. A host (e.g., a tunnel host or a resource host) may consist of a set of containers (also referred to herein as shards) interconnected with each other in a tenant-specific overlay network 128. Tunnel VMs 116 and 122 are used to run tunnel shards per tenant. For example, as shown in FIG. 1, Tunnel VM-1 116 is used to run tunnel shard 120 for a particular tenant / customer of CSPI, and Tunnel VM-2 122 is used to run tunnel shard 126. Each tunnel shard 120 or 126 is responsible for providing a secure connection to the customer's external site representation 106. A set of resource VMs 130 and 132 may be used to run per tenant resource shards.For example, as shown in FIG. 1, resource VM-1 130 is used to run resource shard 136 for that tenant / customer, and resource VM-2 132 is used to run resource shard 140. The resource shards can be used to receive traffic from the customer's VCN and forward it to the customer's external site representation. Additional details of the operations performed by the tunnel shards and resource shards shown in FIG. 1 to provide a secure connection between the customer's external site representation 106 and the customer's VCN 148 are described in detail in FIG. 1.

[0028] Each tunnel VM (116, 122) and resource VM (130, 132) is additionally configured by a host manager (118, 134), respectively. The host managers (118, 134) represent processes that run on the tunnel VMs and resource VMs. The host managers (118 or 134) can implement APIs used to create tunnel and resource shards. In one embodiment, the host managers (118, 134) can be stateless and can operate in an instruction mode (i.e., as a series of commands for the host manager to execute) by receiving instructions from a user (via the API 108) regarding the type of shard (tunnel or resource shard) to be created and certain configurations of the shard. The host manager can additionally be responsible for collecting and monitoring the status of the tunnel and resource shards.

[0029] After the SNCS 104 sets up the tenant-specific overlay network 128 for the customer as described above, in a fourth step, the user registers an on-premise asset (e.g., external resource 114A) in the external site representation 106 as an external endpoint in that VCN. The external resource 114A can represent an on-premise resource or asset such as a database, a computing instance, an application, etc. residing in the customer's on-premise network with which the customer intends to establish a secure bidirectional connection with resources and services residing in the customer's VCN. To register an external resource 114A, the user identifies (via the console UI 108) an external resource (e.g., 114A) that should be enabled for secure private network connectivity from its VCN 148 and registers the external resource as an external endpoint in that VCN using the console UI 108 (or via an API). As part of registering an external resource, the user provides configuration information related to the external resource, such as an on-premise physical IP address associated with the external resource, a port number at which the external resource is accessible, and the hostname (or fully qualified domain name (FQDN)) of the external resource via the console UI or API provided by the SNCS. The user also selects the subnet in the customer's VCN where the external endpoint of the external resource should be created. The SNCS receives the configuration information and creates the external endpoint of the external resource in the customer's VCN. The external endpoint is identified by an IP address, port number, and FQDN (hostname) in the customer's VCN.

[0030] Then, in a fifth step, the SNCS 104 (via the control plane API) creates an external resource representation of the external endpoint in the customer's VCN. In one embodiment, creating the external resource representation includes creating a remote mount point VNIC and assigning the IP address associated with the external endpoint to the VNIC. The SNCS then creates a resource shard on the resource VM to which the VNIC (via the control plane API) can be logically attached (via the worker interface) to the resource shard.

[0031] In a sixth step, the agent 112 downloads and reads configuration information 156 associated with the VNIC 142 created for the external resource representation 114A in the customer's VCN 148, and copies the configuration information 156 onto the registered external resource 114A. The configuration information may include, for example, a virtual IP address of the VNIC, a fully qualified domain name associated with the computing instance associated with the VNIC, and a cloud identifier of a virtual cloud network associated with the customer. Using the configuration information 156, the agent 112 creates / provisions a logical interface 158 for the external resource 114A. The logical interface 158 may represent a software entity consisting of an IP address. In one embodiment, creating or provisioning the logical interface 158 by the agent 112 includes assigning the virtual IP address assigned by the agent to the VNIC 142 created for the external resource representation to the logical interface 158.

[0032] Since the external resource 114A has been provisioned with a logical interface 158 that is assigned a virtual IP address corresponding to the VNIC 142 of the external resource representation that exists in the customer's VCN, the external resource is now part of the customer's VCN and is able to securely access resources and services in the cloud (e.g., in the customer's VCN 148) by using the secure private network connectivity services provided by the SNCS 104. For example, the external resource 114A can securely reach / access a compute instance 150 in the customer's VCN 148 or a service 152 (e.g., streaming service or object storage service) in the customer's VCN through its logical interface 158 by establishing a connection to a tunnel host in the SNCS 104 through the agent 112. Similarly, a client application in the customer's VCN 148 can use the services provided by the SNCS 104 to securely access the external resource 114A in the customer's on-premise network using the VNIC representation 142 of the external resource as if it were connecting to any other native resource in the customer's VCN 148. In this manner, secure bidirectional connectivity between external resources residing within a customer's on-premise network and the customer's resources and services in the cloud (e.g., the customer's VCN) is achieved by the SNCS 104.

[0033] FIG. 2 illustrates additional details of operations performed by the systems and subsystems illustrated in FIG. 1 to provide secure private network connectivity between a customer's external resources residing in the customer's on-premise network and resources and services residing in the customer's VCN, according to an embodiment. The systems and subsystems illustrated in FIG. 2 may be implemented using software (e.g., code, instructions, programs) executed by one or more processing units (e.g., processors, cores) of a computing system, hardware, or combination thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device). The distributed environment 200 illustrated in FIG. 2 is illustrative only and is not intended to unduly limit the scope of the claimed embodiments. Many variations, substitutions, and modifications are possible. For example, in some other embodiments, the distributed environment illustrated in FIG. 2 may have more or fewer systems or components than those illustrated in FIG. 2, may combine two or more systems, or may have a different configuration or arrangement of systems. In FIG. 2, the inventors have described a system that is largely based on the system architecture (SNCS) described in Invention 1 (IaaS 272.1). Please review the explanation for Figure 2 below and add / edit if necessary for greater clarity.

[0034] As previously described in FIG. 1, as part of the connectivity process performed by the SNCS 104 to provide a secure private network connection between a customer's on-premise network and the customer's VCN hosted by the CSPI 102, a user (e.g., an administrator) associated with the customer creates an "external site representation" (e.g., 106) of the customer's on-premise network, configures an agent (e.g., 112) within the external site representation, registers on-premise assets within the external site representation, and creates remote mount points (also referred to herein as endpoints) within the customer's VCN for the registered external resources. Upon successful installation of the agent (e.g., 112) within the external site representation, the agent 112 establishes a virtual private network (VPN) connection (also referred to herein as a VPN tunnel) to the SNCS 104 over a public network (e.g., the Internet 110). The VPN connection is an encrypted connection between the customer's external site representation 106 and the customer's VCN 148. In one embodiment, the VPN connection utilizes a secure tunneling protocol (e.g., the Layer 2 Tunneling Protocol (L2TP) protocol) to establish a secure private network connection to the SNCS 104 over the Internet 110. Once the agent 112 is installed within the external site representation 106, the agent initiates a bootstrap process to activate itself with the SNCS 104 by passing information to the SNCS 104 such as the compartment identifier associated with the agent 112 and the external site representation identifier in a configuration file. Once the agent 112 bootstraps itself, it communicates with the control plane of the SNCS which initiates the registration and activation process. During the activation process, the control plane sends back all the necessary information (e.g., certificates, public ID, etc.) required by the gateway device to establish a secure tunnel connection to the VPN server.Agent 112 then establishes a secure VPN connection to SNCS 104 by executing a VPN client program that opens a secure VPN tunnel connection to a VPN server located on the SNCS. The secure tunnel terminates on a tunnel shard (e.g., 120) that is located on a tunnel VM (e.g., 116) in SNCS 104.

[0035] In the particular embodiment shown in FIG. 1, agent 112 is configured with two VPN clients, namely VPN client 1 206 and VPN client 2 208, each configured to establish tunnels terminating on two different VPN servers, namely VPN server 1 224 and VPN server 2 226, operating in multiple tunnel shards, namely tunnel shard 1 120 and tunnel shard 2 126, respectively. In the embodiment shown in FIG. 2, as a result of every physical installation of agent 112, two tunnels are established, so that if one tunnel fails, traffic (i.e., network packets) can be automatically routed around the second tunnel. Although the particular embodiment shown in FIG. 2 shows two tunnels, in other embodiments, SNCS 104 may be configured to implement three or more redundant tunnels for every physical installation of agent 112, or may simply implement a single tunnel upon installation of agent 112.

[0036] In one embodiment, agent 112 establishes BGP peering sessions with tunnel shards 120 and 126 using a standard exterior gateway protocol such as Border Gateway Protocol (BGP). Using BGP, agent 112 exchanges routing and reachability information with the tunnel shards over a public interface 220 implemented within agent 112. As part of the configuration information required for the BGP peering session, agent 112 injects its on-premise IP address into its local route table 212 (also referred to herein as a routing information base (RIB)) that is received by the tunnel shard. The tunnel shard imports the routing information into its local route tables (228 and 236) after applying appropriate route filtering policies. Route filtering preferably ensures that a faulty agent 112 does not inject arbitrary routes into the tunnel shards. In one example, agent 112 additionally includes a routing manager 214. Routing manager 214 may be implemented using an open source routing manager (e.g., Zebra) that is part of a routing suite (e.g., Quagga). When a BGP peering session learns a route and imports it into its route table 212, the BGP peering session performs a best route calculation and uses the routing manager 214 to add the best route to the local kernel.

[0037] A tunnel shard (e.g., 120, 126) may be composed of a set of one or more containers. In one embodiment, a tunnel shard (120 or 126) may comprise a shell container that can be used to set up various network interfaces that allow the tunnel shard to communicate with both the agent 112 and other shards (e.g., resource shards 136 and 140) that are part of the tenant-specific overlay network 128. In the embodiment shown in FIG. 2, the network interfaces implemented in the shell container nets in the tunnel shard may include an external site interface (esi), a tunnel interface, and a shard backend interface. For example, the network interfaces implemented in tunnel shard 1 120 include tunnel interface 216, external site interface 222, and shard backend interface 234. Similarly, the network interfaces implemented in tunnel shard 2 126 include tunnel interface 218, external site interface 223, and shard backend interface 235. A tunnel shard (e.g., 120 or 126) additionally consists of a VPN server (224, 226) that is used to establish a VPN tunnel to a VPN client (206, 208) running in the external gateway device 112. The external site interface (222, 223) is known to the agent 112 on which the VPN client runs and can be identified by the public IP that is used to establish a tunnel to the tunnel shard. When a VPN client (e.g., 206, 208) connects to a VPN server (224, 226), a tunnel interface (216, 218) is created and placed in the pre-configured VPN subnet of the tunnel shard.

[0038] In one embodiment, each tunnel shard (e.g., 120, 126) can utilize the Border Gateway Protocol (BGP) to establish BGP peering sessions between external gateway devices and the tunnel shards and between the tunnel shards and resource shards. The BGP peering sessions are used to exchange routing and reachability information with the resource shards via the shard backend interfaces (234, 235) and with the external site representations 106 via the external site interfaces (222, 223). As part of the configuration information required for the BGP peering sessions, IP addresses identifying the tenant-specific overlay networks 128 are added to route tables 228, 236 (i.e., routing information bases (RIBs)) implemented within the tunnel shards 120, 126, respectively. In one embodiment, classless inter-domain routing (CIDR) techniques can be used to allocate IP addresses to the tenant-specific overlay networks. The route tables (228, 236) list routes to specific network destinations, such as resource shards (136, 140) and external site representations 106. In some cases, the route tables (228, 236) also list metrics (distances) associated with those routes. When a BGP peering session with a resource shard is established, the routes in the route tables are propagated to the resource shard. As shown in FIG. 2, each tunnel shard (120, 126) additionally includes a routing manager (228, 240). The routing manager (228 or 240) may be implemented similarly to the routing manager (214) implemented in the external gateway device 112. Once BGP learns routes and imports them into the route tables in the tunnel shards, BGP performs a best route calculation and pushes the best routes to the external site representations 106 and resource shards 136, 140 using the routing manager.

[0039] A resource shard (136, 140) may be composed of a set of containers. In one embodiment, the resource shard (136, 140) may comprise a shell container that can be used to set up virtual tunnel endpoints (VTEPs) (242, 243) with the tunnel shards (116, 126). Each resource shard (136, 140) may use BGP to establish peering sessions with the tunnel shards and exchange routing and reachability information with the tunnel shards via the virtual tunnel endpoints (242, 243). The resource shards (136, 140) additionally comprise a routing manager (250, 260) configured to perform the same functions as the routing manager (232 or 240) implemented in the tunnel shard. Each resource shard (136, 140) additionally includes a proxy server (244, 254). The proxy server (244 or 254) can be configured to accept connections from client applications 144 within the customer's VCN 148 and to initiate new connections to external resources within the external site representation.

[0040] In one embodiment, for every registered external endpoint (i.e., corresponding to an external resource in the external site representation), a unique proxy server container is launched and attached to the resource shard. When registering an external resource and creating a remote mount point VNIC for the registered external endpoint in the customer's VCN, the user can provide configuration information to SNCS 104, such as the IP address of the external resource, the port number of the external resource, and the name of the external resource. This configuration information is provisioned in the proxy server and used by a client application in the customer's VCN to connect to the external resource. Once the external resource is successfully registered by SNCS as an external endpoint in the customer's VCN, SNCS 104 (via a control plane API) creates a VNIC and assigns the IP address associated with the external endpoint to the VNIC.

[0041] In the example shown in FIG. 2, the registered external endpoints (i.e., external resources in the external site representation) represent a database 202 that exists in the external site representation 106. The proxy servers (244, 254) listen on the virtual IP address assigned to the VNIC 206 created for the registered external endpoint 202. This ensures that the same VNIC IP cannot be used to access other registered external resources in the external site representation. When a client application 144 running in the customer's VCN receives a query for information stored in the external database 202, the client application sends a network packet to the VNIC IP in the customer's VCN. The network packet is received by a worker VNIC (251, 252) that is attached to a resource shard (136, 140). The worker VNIC is configured with the virtual IP address of the VNIC, thereby initiating a connection to the registered external resource in the external site representation through the proxy servers (244, 254). The proxy servers (244, 254) perform network address translation (NAT) to translate the virtual IP address assigned to the VNIC 206 to the real / physical IP address of the external resource 114A in the external site representation 106. The resource shards (e.g., 136, 140) using the proxy servers (244, 254) initiate a connection to the agent 112 via the tunnel shards (120, 126). The agent 112 receives network packets from the tunnel shards (120, 126) and then routes the packets to the registered external resources (i.e., database 202) in the external site representation 106. The proxy servers (244, 254) additionally include functionality to load balance network traffic to the external resources across the tunnel shards. In one embodiment, the proxy servers (244, 254) can be configured to multiplex connections from multiple client applications into a single connection directed to the external site representation.

[0042] Similarly, a registered external resource (i.e., database 202) residing in the external site representation 106 can reach out and securely access resources (e.g., compute instance 150) or services (e.g., private endpoint VNIC 152) residing in the customer's VCN. As previously described in FIG. 1, agent 112 creates / provisions logical interface 204 for external resource 202. By creating logical interface 158 for external resource 114A and assigning the virtual IP address of VNIC representation 206 of database 202 to the logical interface, database 202 (residing in the customer's on-premise network) can securely access compute instance 150 or service 156 (e.g., streaming service or object storage service in CSPI) in customer's VCN 148 via private endpoint VNIC 142 in customer's VCN 148 using the secure private network connectivity service provided by SNCS 104. For example, in the embodiment shown in FIG. 2, agent 112 can receive a query from database 202 requesting information associated with resources (e.g., 150) in the customer's VCN. The agent 112 then sends network packets corresponding to the query to the tunnel shard (120, 126). The tunnel shard then initiates a connection to the resource shard (136, 140). A proxy server (244, 254) in the resource shard (136, 140) performs network address translation (NAT) to translate the real IP address of the external resource in the external site representation 106 to the virtual IP address of the VNIC representation 206 of the external resource (e.g., database 202) in the customer's VCN. A worker VNIC (251, 252) attached to the resource shard (136, 140) then initiates a connection to the VNIC representation 206 of the database 202 in the customer's VCN, which sends the network packets corresponding to the query to the requesting resource (e.g., 150) in the customer's VCN.In this manner, the SNCS 104 ensures that secure, private, bidirectional network connectivity is established between external resources (e.g., database 202) residing within the customer's on-premise network and resources (e.g., 150) and services (e.g., 152) within the customer's VCN (i.e., cloud).

[0043] In one embodiment, a registered external endpoint requesting a private connection from a customer's VCN 148 may be implemented as a Service VNIC, also referred to herein as an "SVNIC" within the customer's VCN 148. The SVNIC may be implemented using a VNIC as a Service (VNICaaS) system (not shown in FIG. 2) that can represent a horizontally scalable service implemented by CSPI 102 that can host multiple VNICs (e.g., Service VNICs 254) to process and transmit traffic between virtual cloud networks. Specifically, VNICaaS is a virtual networking feature that allows a VNIC to be represented or used as a service (i.e., SVNIC). VNICaaS provides the functionality of a VNIC without requiring the hosting of a specific SmartNIC or compute instance within the virtual network to host the VNIC. Techniques used to represent registered endpoints as SVNICs are described in detail in U.S. Patent Application Serial No. 17 / 175,573, entitled "Techniques for high performant virtual routing capabilities." The techniques described in U.S. Patent Application No. 17 / 175,573 are intended as examples only and are not intended to be limiting. In alternative embodiments, various other techniques may also be used to represent registered endpoints and process and transmit traffic between virtual cloud networks. A SVNIC is created for every registered external endpoint (e.g., database 202), allowing a flexible number of workers to be configured per SVNIC. In certain embodiments, every SVNIC may be associated with two worker VNICs (e.g., 251, 252) that are attached to different resource shards (e.g., 136, 140). The worker VNICs are placed into resource shards and configured with the SVNIC IP.

[0044] In the particular embodiment shown in FIG. 2, a single agent 112 is installed in the external site representation 106 and configured to establish two tunnels resulting in a total of two tunnel shards that need to be placed on the tunnel fleet implemented by the SNCS 104. For a fixed number of tunnel shards as described in this embodiment, every resource shard can be pre-configured with a fixed set of BGP peers along with static Address Resolution Protocol (e.g., ARP) entries for those peers. In one approach, the BGP container on the tunnel shard can be configured with a "dynamic BGP peer" that can specify a CIDR block of IP addresses from where BGP can accept incoming connections. This CIDR block can be set to the CIDR of the tenant-specific overlay network, so that as the resource shard grows / shrinks, the BGP peers on the tunnel shard also change appropriately. From the resource shard's perspective, at this point, every resource shard has two BGP peering connections, and every resource shard has two equal-cost routes towards the on-premises network because each of the BGP peers propagates the same CIDR route to the on-premises network that it learns from the external site representation. Similarly, from the perspective of the external gateway, the agent 112 establishes two tunnels toward the SNCS 104, the tunnel shards advertise the tenant-specific overlay network routes to the agent 112, and the agent then installs the appropriate routes to the tenant-specific overlay networks.

[0045] Using the novel and improved architecture of the present disclosure implemented by the SNCS 104, a secure, private, bidirectional network connection between external resources in the customer's external site representation and resources and services residing in the customer's VCN in the cloud can be achieved without the need for an enterprise user (e.g., an administrator) to explicitly configure the external resources, advertise routes, or set up site-to-site network connections. As described, the secure, private, bidirectional network connection is established by the SNCS using an encrypted connection between the customer's external site representation and the customer's VCN and by authenticating an agent before setting up a tenant-specific overlay network for the customer. The SNCS 104 provides high-performance, scalable, and highly available site-to-site network connectivity for handling network traffic between the customer's on-premise environment and the CSPI by implementing a robust infrastructure of network elements and computing nodes (i.e., tenant-specific overlay network 128) for each tenant / customer that uses the services provided by the SNCS 104. Tunnel hosts in the tenant-specific overlay network 128 are used to provide secure connectivity to the customer's external site representation 106, and resource hosts are used to receive traffic from the customer's VCN and forward it to the customer's external site representation. The resource hosts can additionally receive traffic from external resources in the external site representation and forward it to resources or services that reside in the customer's VCN. By using the robust infrastructure of network elements and computing nodes implemented by the tenant-specific overlay network, an enterprise can securely access its external resources from the cloud as if it were connected to any other native resource in its VCN.An enterprise's users can access its external resources without setting up intricate site-to-site networks between its on-premise networks and the cloud, without making any changes to its external resources, and without configuring the routes used by the site-to-site connections. Similarly, by creating a logical interface for the external resource and associating the logical interface with a virtual IP address of the external resource's VNIC representation, an external resource (residing in the customer's on-premise network) can securely access resources and services residing in the cloud (e.g., in the customer's VCN 148) using the secure private network connectivity services provided by SNCS 104.

[0046] FIG. 3 illustrates an example of a process performed by the systems and subsystems illustrated in FIG. 1 to provide secure private network connectivity, according to an embodiment. The process illustrated in FIG. 3 may be implemented in software (e.g., code, instructions, programs) executed by one or more processing units (e.g., processors, cores) of the respective systems, hardware, or combinations thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device). The process 300 presented in FIG. 3 and described below is intended to be exemplary and non-limiting. Although FIG. 3 illustrates various processing steps occurring in a particular sequence or order, this is not intended to be limiting. In an alternative embodiment, the steps may be performed in some different order, or some steps may also be performed in parallel. In an embodiment, such as the embodiment illustrated in FIG. 1, the process illustrated in FIG. 3 may be performed by computing nodes (e.g., 116, 122, 130, and 132) that comprise a tenant-specific overlay network 128.

[0047] The process illustrated in Figure 3 assumes that a user (e.g., administrator) associated with a customer has created an external site representation (e.g., 106) of the customer's on-premise network and configured an agent (e.g., 112) within the external site representation 106. The process illustrated in Figure 4 further assumes that the SNCS 104 has authenticated the agent 112 and configured / established a tenant-specific overlay network (e.g., 128) that includes a distributed, horizontally scalable fleet of computing nodes for the customer. As described in Figure 1, the set of one or more computing nodes includes resource hosts (i.e., resource virtual machines 130, 132) and tunnel hosts (i.e., tunnel virtual machines 116, 122).

[0048] 3 may begin at block 302 when the SNCS 104 executes a tenant-specific overlay network (e.g., 128) that includes a distributed, horizontally scalable fleet of computing nodes. The tenant-specific overlay network is used to establish secure, private network connectivity between a customer's external site representation and the customer's VCN (e.g., 148) within the CSPI.

[0049] In block 304, the SNCS (via control plane APIs) registers an external resource that resides in the customer's on-premise network as an external endpoint in the customer's VCN. The external endpoint is identified by an IP address in the customer's VCN. As previously mentioned, the external resource may represent a database, a computing instance, or an application in the external site representation 106 to which the customer intends to enable secure bidirectional private network connectivity from within its VCN. As part of registering the external resource, a user of the SNCS provides configuration information related to the external resource, such as an on-premise physical IP address associated with the external resource via a console UI or API, a port number through which the external resource is accessible, and the hostname (or fully qualified domain name (FQDN)) of the external resource. The user also selects a subnet in the customer's VCN in which the external endpoint of the external resource should be created. Based on the configuration information, the SNCS creates an external endpoint for the external resource in the customer's VCN. The external endpoint is identified by an IP address, port number and FQDN (hostname) in the customer's VCN.

[0050] In block 306, a first computing node in the SNCS (e.g., resource VM 130 or resource VM 132) creates an external resource representation of an external endpoint in the customer's VCN. In one embodiment, creating the external resource representation includes creating, by the computing node, a VNIC and assigning an IP address of the external endpoint to the VNIC.

[0051] In block 308, the first computing node sends configuration information corresponding to the VNIC created for the external resource representation in the customer's VCN to the agent 112 configured in the on-premises network. As part of the process performed in block 308, the agent 112 downloads and copies the configuration information to the registered external resource present in the on-premises network. As previously described, the configuration information may include, for example, the virtual IP address of the VNIC, a fully qualified domain name associated with the computing instance associated with the VNIC, and a cloud identifier of the virtual cloud network associated with the customer. Using the configuration information, the agent 112 creates / provisions a logical interface (e.g., 158) for the external resource (e.g., 114A). In one embodiment, creating or provisioning the logical interface by the agent 112 includes assigning, by the agent, the virtual IP address assigned to the VNIC 142 created for the external resource representation to the logical interface 158 provisioned for the external resource 114A.

[0052] At block 310, a second computing node (e.g., tunnel VM 116 or tunnel VM 122) receives a request to query information associated with a resource (e.g., compute instance 150) residing in the customer's VCN. In one example, the request is sent by an external resource (e.g., 114A) residing in the on-premises network via its logical interface 158. For example, a user associated with the customer can send a request (via UI 108) to an external resource residing in the customer's on-premises network to query information associated with compute instance 150 residing in the customer's VCN. The external resource can then send the query to agent 112 residing in the on-premises network. Agent 112 receives the query request and sends a network packet corresponding to the query request to a tunnel shard (120 or 126) running in the tunnel VM.

[0053] At block 312, a second computing node (e.g., Tunnel VM 116 or Tunnel VM 122) establishes a connection between the logical interface provisioned to the external resource and the VNIC created for the representation of the external resource in the customer's VCN via a resource shard (e.g., 136 or 140). In certain embodiments, the tunnel shard (e.g., 120 or 126) may include functionality to translate a real / physical IP address assigned to the external resource to a virtual IP address of the VNIC 142 and initiate a connection to the VNIC 142 via the resource shard (136 or 140). The resource shard then initiates a connection to the resource (e.g., 150) in the customer's VCN.

[0054] At block 314, a second computing node (e.g., tunnel VM 116 or tunnel VM 122) sends a request to a resource residing in the customer's VCN via the connection established at block 410. At block 412, the second computing node obtains a result corresponding to the request via the established connection. The result is then sent via agent 112 to the external resource residing in the external site representation. For example, if the resource is a database operating in the customer's VCN, the result may include information stored in one or more tables in the database.

[0055] FIG. 4 is a flow chart illustrating the flow of network packets between an external resource residing in a customer's on-premise network and a representation of the external resource in the customer's virtual cloud network, according to an embodiment. The process illustrated in FIG. 4 may be implemented in software (e.g., code, instructions, programs) executed by one or more processing units (e.g., processors, cores) of the respective systems, hardware, or combinations thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device). The process 400 presented in FIG. 4 and described below is intended to be exemplary and non-limiting. Although FIG. 4 illustrates various processing steps occurring in a particular sequence or order, this is not intended to be limiting. In an alternative embodiment, the steps may be performed in some different order, or some steps may also be performed in parallel. In an embodiment, such as the embodiment illustrated in FIG. 2, the process illustrated in FIG. 4 may be performed by computing nodes (e.g., 116, 122, 130, and 132) that comprise a tenant-specific overlay network 128.

[0056] The process illustrated in FIG. 4 may begin at block 402 when an external resource (e.g., database 202) residing within a customer's on-premises network (i.e., customer's external site representation 106) receives a query for information associated with a resource (e.g., 150) residing within the customer's VCN (e.g., 148). As previously described, a user associated with the customer may send a request (via UI 108) to the external resource residing within the customer's on-premises network to query information associated with a compute instance 150 residing within the customer's VCN. The external resource may then send the query to an agent 112 residing within the on-premises network.

[0057] At block 404, the agent 112 receives the query and sends network packets corresponding to the query to a tunnel shard (120 or 126) running in the tunnel VM. In one example, as part of the processing performed at block 404, the agent 112 can encrypt the network packets before sending them to the tunnel shard.

[0058] In block 406, the tunnel shard receives the encrypted network packet and transmits the encrypted network packet to the resource shard (136, 140) running in the resource VM. Specifically, as shown in FIG. 2, the encrypted network packet can be received by the worker VNIC (251, 252) attached to the resource shard (136, 140).

[0059] In block 408, the resource shard (136, 140) decrypts the network packet and performs network address translation (NAT) to convert the physical IP address assigned to the external resource to the virtual IP address of a VNIC (e.g., 206) associated with the external resource representation in the customer's VCN.

[0060] In block 410, the resource shard (136, 140) sends the network packet to the VNIC created for the external resource representation in the customer's VCN.

[0061] In block 412, the VNIC sends a network packet corresponding to the query to a resource (eg, 150) residing in the customer's VCN.

[0062] FIG. 5 is a flow chart illustrating the flow of network packets between an external resource representation in a customer's virtual cloud network and an external resource residing in the customer's on-premise network, according to an embodiment. The process illustrated in FIG. 5 may be implemented in software (e.g., code, instructions, programs) executed by one or more processing units (e.g., processors, cores) of the respective systems, hardware, or combinations thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device). The process 500 presented in FIG. 5 and described below is intended to be exemplary and non-limiting. Although FIG. 5 illustrates various processing steps occurring in a particular sequence or order, this is not intended to be limiting. In an alternative embodiment, the steps may be performed in some different order, or some steps may also be performed in parallel. In an embodiment, such as the embodiment illustrated in FIG. 2, the process illustrated in FIG. 5 may be performed by computing nodes (e.g., 116, 122, 130, and 132) that comprise a tenant-specific overlay network 128.

[0063] The process illustrated in FIG. 5 may begin at block 502 when a client application (e.g., 144) in a customer's VCN receives a query for information associated with an external resource (e.g., 202) that resides in the customer's on-premise network (i.e., the customer's external site representation 106). For example, the query may be received from a user associated with the customer via the client application. As part of the process performed at block 502, the client application 144 initiates a connection to a VNIC (e.g., 206) associated with the external resource representation by sending a network packet corresponding to the query to a virtual IP address assigned to the VNIC in the customer's VCN.

[0064] In block 504, the client application sends a network packet corresponding to the query to a resource shard (136 or 140) running in a resource VM in the SNCS. Specifically, as shown in FIG. 2, the network packet can be received by a worker VNIC (251, 252) attached to the resource shard (136, 140). A proxy server (244, 254) in the resource shard (136, 140) performs network address translation (NAT) to translate the virtual IP address assigned to the VNIC into the physical IP address of the external resource in the external site representation 106, and initiates a connection to the agent 112 via the tunnel shard (120, 126).

[0065] At block 506, the resource shard sends the network packet to the tunnel shard (120, 126). As part of the processing performed at block 506, the tunnel shard may encrypt the network packet received from the resource shard before sending the packet to the agent 112 in the external site representation 106.

[0066] At block 508, the tunnel shard sends the network packet to an agent 112 that resides in the customer's external site representation. As part of the processing performed at block 508, the agent 112 decrypts the network packet before sending it to an external resource (e.g., 202) in the external site representation (e.g., 106).

[0067] At block 510, the agent 112 sends a network packet to an external resource (e.g., 202) that resides within the customer's external site representation. The external resource receives the network packet corresponding to the query and generates a response network packet corresponding to the query. The response network packet can then be sent by the external resource back to the client application. For example, as part of the response network packet flow, a network packet corresponding to a response to the query is sent from the external resource to the agent. The agent encrypts the network packet and sends the encrypted network packet to the tunnel shard. The tunnel shard receives the encrypted packet and sends the packet to the resource shard. The resource shard decrypts the network packet and performs a reverse network address translation (NAT) to translate the physical / real IP address assigned to the external resource to the virtual IP address of a VNIC associated with the external resource representation in the customer's VCN. The resource shard then sends the response network packet to the VNIC, which then sends the response packet to the requesting client application 144 in the customer's VCN 148.

[0068] Exemplary Virtual Networking Architecture The term cloud services is generally used to refer to services made available by a cloud service provider (CSP) to users or customers on demand (e.g., via a subscription model) using systems and infrastructure (cloud infrastructure) provided by the CSP. Typically, the servers and systems that make up the CSP's infrastructure are separate from the customer's own on-premise servers and systems. Thus, customers can utilize cloud services provided by the CSP without having to purchase separate hardware and software resources for the service. Cloud services are designed to provide subscribing customers with easy and scalable access to applications and computing resources without the customer having to invest in acquiring the infrastructure used to provide the service.

[0069] There are several cloud service providers that offer different types of cloud services. There are a variety of different types or models of cloud services, including Software as a Service (SaaS), Platform as a Service (PaaS), Infrastructure as a Service (IaaS), etc.

[0070] A customer may subscribe to one or more cloud services offered by a CSP. A customer may be any entity such as an individual, an organization, a business, etc. When a customer subscribes or registers for a service offered by a CSP, a tenancy or account is created for the customer. Through this account, the customer may then access the subscribed cloud resources or resources associated with the account.

[0071] As mentioned above, Infrastructure as a Service (IaaS) is one particular type of cloud computing service. In the IaaS model, the CSP provides infrastructure (referred to as Cloud Service Provider Infrastructure or CSPI) that can be used by customers to build their own customizable networks and deploy customer resources. Thus, the customer's resources and networks are hosted in a distributed environment by the infrastructure provided by the CSP. This differs from traditional computing, where the customer's resources and networks are hosted by the infrastructure provided by the customer.

[0072] CSPI can include interconnected high performance computing resources including various host machines, memory resources, and network resources that form a physical network, also referred to as infrastructure or underlay network. Resources in CSPI can be distributed across one or more data centers that can be geographically distributed across one or more geographic regions. These physical resources can run virtualization software to provide a virtualized distributed environment. Virtualization creates an overlay network (also known as a software-based network, software-defined network, or virtual network) on top of the physical network. The CSPI physical network provides the underlying infrastructure for creating one or more overlay or virtual networks on top of the physical network. The physical network (or infrastructure or underlay network) includes physical network devices such as physical switches, routers, computers, and host machines. An overlay network is a logical (or virtual) network that operates on top of the physical infrastructure network. A given physical network can support one or more overlay networks. An overlay network typically uses encapsulation techniques to differentiate traffic belonging to different overlay networks. A virtual or overlay network is also referred to as a virtual cloud network (VCN). Virtual networks are implemented using software virtualization techniques (e.g., hypervisors, virtualization functions implemented by network virtualization devices (NVDs) (e.g., smartNICs), top-of-rack (TOR) switches, smart TORs that implement one or more functions performed by NVDs, and other mechanisms) to create a layer of network abstraction that can operate on top of a physical network. Virtual networks can take many forms, including peer-to-peer networks, IP networks, etc. Virtual networks are typically either layer-3 IP networks or layer-2 VLANs.This virtual or overlay networking method is often referred to as virtual or overlay Layer 3 networking. Examples of protocols deployed for virtual networks include IP-in-IP (or Generic Routing Encapsulation (GRE)), Virtual Extensible LANs (VXLAN-IETF RFC7348), Virtual Private Networks (VANs) (e.g., MPLS Layer 3 Virtual Private Networks (RFC4364)), VMware's NSX, GENEVE (Generic Network Virtualization Encapsulation), etc.

[0073] In the case of IaaS, the infrastructure (CSPI) provided by the CSP can be configured to provide virtualized computing resources over a public network (e.g., the Internet). In the IaaS model, the cloud computing service provider can host the infrastructure components (e.g., servers, storage devices, network nodes (e.g., hardware), deployment software, platform virtualization (e.g., hypervisor layer), etc.). In some cases, the IaaS provider can also provide various services (e.g., billing, monitoring, logging, security, load balancing, and clustering, etc.) to accompany those infrastructure components. Thus, these services can be policy-driven, so that IaaS users can implement policies to drive load balancing to maintain application availability and performance. CSPI provides an infrastructure and a set of complementary cloud services that enable customers to build and run diverse applications and services in a highly available, hosted, distributed environment. CSPI provides high-performance computing resources and capabilities as well as storage capacity in a flexible virtual network that is securely accessible from various networked locations, such as the customer's on-premise network. When a customer subscribes or registers for an IaaS service offered by a CSP, the tenancy that is created for that customer is a secure, isolated division within the CSP where the customer can create, organize, and manage its cloud resources.

[0074] Customers can build their own virtual networks using compute, memory, and networking resources provided by CSPI. On these virtual networks, one or more customer resources or workloads, such as compute instances, can be deployed. For example, customers can build one or more customizable private virtual networks, referred to as Virtual Cloud Networks (VCNs), using resources provided by CSPI. On the customer VCN, customers can deploy one or more customer resources, such as compute instances. The compute instances can take the form of virtual machines, bare metal instances, etc. Thus, CSPI provides an infrastructure and a set of complementary cloud services that enable customers to build and run a variety of applications and services within a highly available, virtual hosted environment. Although customers do not manage or control the underlying physical resources provided by CSPI, they can control the operating systems, storage, and applications being deployed, and in some cases, have limited control over the selection of networking components (e.g., firewalls).

[0075] The CSP may provide a console that allows customers and network administrators to configure, access, and manage resources deployed in the cloud using CSPI resources. In some embodiments, the console provides a web-based user interface that can be used to access and manage the CSPI. In some implementations, the console is a web-based application provided by the CSP.

[0076] CSPI can support single-tenancy or multi-tenancy architectures. In a single-tenancy architecture, a software (e.g., application, database) or hardware component (e.g., host machine or server) serves a single customer or tenant. In a multi-tenancy architecture, a software or hardware component serves multiple customers or tenants. Thus, in a multi-tenancy architecture, CSPI resources are shared among multiple customers or tenants. In a multi-tenancy situation, precautions are taken and safeguards are implemented within CSPI to ensure that each tenant's data remains isolated and invisible to other tenants.

[0077] In a physical network, a network endpoint ("endpoint") refers to a computing device or system that is connected to the physical network and communicates to and from the connected network. Network endpoints in a physical network may be connected to a local area network (LAN), a wide area network (WAN), or other types of physical networks. Examples of traditional endpoints in a physical network include modems, hubs, bridges, switches, routers, and other networking devices, physical computers (or host machines), and the like. Each physical device in a physical network has a fixed network address that can be used to communicate with the device. This fixed network address can be a layer 2 address (e.g., a MAC address), a fixed layer 3 address (e.g., an IP address), and the like. In a virtualized environment or underlay network, the endpoints can include various virtual endpoints, such as virtual machines hosted by components of the physical network (e.g., hosted by a physical host machine). These endpoints in the virtual network are addressed by overlay addresses, such as overlay layer 2 addresses (e.g., an overlay MAC address) and overlay layer 3 addresses (e.g., an overlay IP address). Network overlays enable flexibility by allowing network managers to move overlay addresses associated with network endpoints around using software management (e.g., via software implementing the virtual network's control plane). Thus, unlike physical networks, in a virtual network, overlay addresses (e.g., overlay IP addresses) can be moved from one endpoint to another using network management software. Because virtual networks are built on top of physical networks, communication between components in a virtual network involves both the virtual network and the underlying physical network.To facilitate such communications, CSPI components are configured to learn and store mappings of overlay addresses in the virtual network to actual physical addresses in the underlying network, and vice versa, where these mappings are then used to facilitate communications. Customer traffic is encapsulated to facilitate routing within the virtual network.

[0078] Thus, a physical address (e.g., a physical IP address) is associated with an entity in a physical network, and an overlay address (e.g., an overlay IP address) is associated with an entity in a virtual or overlay network. A physical IP address is an IP address associated with a physical device (e.g., a network device) in an underlying or physical network. For example, each NVD has a physical IP address associated with it. An overlay IP address is an overlay address associated with an entity in an overlay network, such as a compute instance in a customer's virtual cloud network (VCN). Two different customers or tenants, each with their own private VCN, can potentially use the same overlay IP address in that VCN without ever knowing about each other. Both physical and overlay IP addresses are types of real IP addresses. They are distinct from virtual IP addresses. A virtual IP address is typically a single IP address that represents or maps to multiple real IP addresses. A virtual IP address provides a one-to-many mapping between a virtual IP address and multiple real IP addresses. For example, a load balancer can use a VIP to map to or represent multiple servers (each server having its own real IP address).

[0079] A cloud infrastructure or CSPI is physically hosted in one or more data centers in one or more regions around the world. The CSPI can include components in the physical or foundation network and virtualized components (e.g., virtual networks, compute instances, virtual machines, etc.) in virtual networks built on top of the physical network components. In one embodiment, the CSPI is organized and hosted in realms, regions, and availability domains. A region is a local geographic area that typically includes one or more data centers. Regions are generally independent of each other and can be separated by large distances, for example across countries or even continents. For example, a first region may be in Australia, another region may be in Japan, yet another region may be in India, etc. CSPI resources are divided among multiple regions, so that each region has its own independent subset of CSPI resources. Each region can provide a set of core infrastructure services and resources, such as compute resources (e.g., bare metal servers, virtual machines, containers and related infrastructure, etc.), storage resources (e.g., block volume storage, file storage, object storage, archival storage), networking resources (e.g., virtual cloud networks (VCNs), load balancing resources, connections to on-premises networks), database resources, edge networking resources (e.g., DNS), and access management and monitoring resources, etc. Each region typically has multiple routes connecting it to other regions in the realm.

[0080] Because using nearby resources is faster than using distant resources, applications are typically deployed in the region where they are most heavily used (i.e., on the infrastructure associated with that region). Applications may also be deployed in different regions for a variety of reasons, such as redundancy to mitigate region-wide risks such as large-scale weather systems or earthquakes, to meet the changing requirements of jurisdictions, tax regions, and other business or social standards, etc.

[0081] Datacenters within a region can also be further organized and subdivided into availability domains (ADs). An availability domain can correspond to one or more datacenters located within a region. A region can consist of one or more availability domains. In such a distributed environment, CSPI resources are either region-specific, such as a virtual cloud network (VCN), or availability domain-specific, such as a compute instance.

[0082] ADs within a region are isolated from each other, fault-tolerant, and configured to be highly unlikely to fail at the same time. This is achieved by ADs not sharing critical infrastructure resources such as networking, physical cables, cable paths, cable entry points, etc., so that a failure in one AD in a region is unlikely to affect the availability of other ADs in the same region. ADs within the same region can be connected to each other by low-latency high-bandwidth networks, which provides highly available connections to other networks (e.g., the Internet, customer on-premise networks, etc.) and allows for the creation of replicated systems in multiple ADs for both high availability and disaster recovery. Cloud services use multiple ADs to ensure high availability and protect against resource failures. As the infrastructure provided by IaaS grows, more regions and ADs are added with additional capacity. Traffic between availability domains is typically encrypted.

[0083] In one embodiment, regions are grouped into realms. A realm is a logical collection of multiple regions. Realms are isolated from each other and do not share any data. Regions in the same realm can communicate with each other, but regions in different realms cannot communicate with each other. A customer's tenancy and account with a CSP exists in a single realm and can be spread across one or more regions that belong to that realm. Typically, when a customer subscribes to an IaaS service, the customer's tenancy and account are created in a customer-specified region (referred to as the "home" region) in the realm. The customer can extend the customer's tenancy across one or more other regions in the realm. The customer cannot access a region that is not in the realm in which the customer's tenancy resides.

[0084] An IaaS provider may offer multiple realms, each dedicated to a particular set of customers or users. For example, a commercial realm may be offered to commercial customers. As another example, a realm for a particular country may be offered to customers in that country. As yet another example, a government realm may be offered to a government, and so on. For example, a government realm may be offered to a particular government and may have an increased level of security than a commercial realm. For example, Oracle Cloud Infrastructure (OCI) currently offers one realm of commercial region and two realms of government cloud regions (e.g., FedRAMP authorized and IL5 authorized).

[0085] In one embodiment, an AD can be subdivided into one or more fault domains. A fault domain is a grouping of infrastructure resources within an AD to provide anti-affinity. Fault domains allow for distributing compute instances such that the instances are not on the same physical hardware within a single AD. This is known as anti-affinity. A fault domain refers to a set of hardware components (computers, switches, etc.) that share a single point of failure. A compute pool is logically divided into multiple fault domains. Due to this, a hardware failure or compute hardware maintenance event that affects one fault domain does not affect instances in other fault domains. Depending on the embodiment, the number of fault domains in each AD can vary. For example, in one embodiment, each AD includes three fault domains. Fault domains act as logical data centers within an AD.

[0086] When a customer subscribes to an IaaS service, resources from CSPI are provisioned to the customer and associated with the customer's tenancy. The customer can use these provisioned resources to build private networks and deploy resources on these networks. A customer network hosted in the cloud by CSPI is referred to as a Virtual Cloud Network (VCN). A customer can set up one or more Virtual Cloud Networks (VCNs) using the CSPI resources allocated to the customer. A VCN is a virtual or software-defined private network. The customer resources deployed in a customer's VCN can include compute instances (e.g., virtual machines, bare metal instances) and other resources. These compute instances can represent various customer workloads such as applications, load balancers, databases, etc. The compute instances deployed on a VCN can communicate with publicly accessible endpoints ("public endpoints") on public networks such as the Internet, other instances in the same VCN or other VCNs (e.g., other VCNs of the customer or VCNs not belonging to the customer), the customer's on-premise data center or network, and service endpoints and other types of endpoints.

[0087] CSPs can provide various services using CSPI. In some cases, customers of CSPI themselves may act as service providers and provide services using CSPI resources. Service providers can expose service endpoints characterized by identification information (e.g., IP addresses, DNS names and ports). Customer resources (e.g., compute instances) can consume a particular service by accessing the service endpoints exposed by the service for that particular service. These service endpoints are typically endpoints that are publicly accessible by users using a public IP address associated with the endpoint over a public communications network such as the Internet. Publicly accessible network endpoints are sometimes referred to as public endpoints.

[0088] In some embodiments, a service provider may expose a service via an endpoint for that service (sometimes referred to as a service endpoint). A customer of the service may then use this service endpoint to access the service. In some embodiments, a service endpoint provided for a service may be accessed by multiple customers who intend to consume the service. In other embodiments, a dedicated service endpoint may be provided for a customer, so that only that customer can access the service using the dedicated service endpoint.

[0089] In one embodiment, when a VCN is created, it is associated with a private overlay Classless Inter-Domain Routing (CIDR) address space, which is a range of private overlay IP addresses (e.g., 10.0 / 16) that are assigned to the VCN. A VCN includes associated subnets, route tables, and gateways. A VCN exists within a single region but can span one or more or all of the region's availability domains. A gateway is a virtual interface configured for a VCN that enables traffic to and from the VCN to one or more networks outside the VCN. One or more different types of gateways may be configured for a VCN to enable communication to and from different types of endpoints.

[0090] A VCN can be subdivided into one or more subnetworks, such as one or more subnets. A subnet is thus a unit of organization or subdivision that can be created within a VCN. A VCN can have one or more subnets. Each subnet in a VCN is associated with a contiguous range of overlay IP addresses (e.g., 10.0.0.0 / 24 and 10.0.1.0 / 24) that do not overlap with other subnets in that VCN and that represent a subset of address space within the VCN's address space.

[0091] Each compute instance is associated with a virtual network interface card (VNIC) that allows the compute instance to participate in a subnet of a VCN. A VNIC is a logical representation of a physical network interface card (NIC). In general, a VNIC is an interface between an entity (e.g., a compute instance, a service) and a virtual network. A VNIC resides in a subnet, has one or more associated IP addresses, and is associated with a security rule or policy. A VNIC is equivalent to a layer 2 port on a switch. A VNIC is attached to a compute instance and a subnet in a VCN. A VNIC associated with a compute instance allows the compute instance to be part of a subnet of a VCN, allowing the compute instance to communicate (e.g., send and receive packets) with endpoints on the same subnet as the compute instance, endpoints in a different subnet in the VCN, or endpoints outside the VCN. Thus, a VNIC associated with a compute instance determines how the compute instance connects with endpoints inside and outside the VCN. When a compute instance is created and added to a subnet in a VCN, a VNIC for the compute instance is created and associated with the compute instance. For a subnet that includes a set of compute instances, the subnet includes VNICs that correspond to the set of compute instances, and each VNIC is attached to a compute instance in the set of compute instances.

[0092] Each compute instance is assigned a private overlay IP address via the VNIC associated with the compute instance. This private overlay IP address is assigned to the VNIC associated with the compute instance when the compute instance is created and is used to route traffic to and from the compute instance. All VNICs within a given subnet use the same route table, security lists, and DHCP options. As described above, each subnet in a VCN is associated with a contiguous range of overlay IP addresses (e.g., 10.0.0.0 / 24 and 10.0.1.0 / 24) that do not overlap with other subnets in that VCN and that represent a subset of address space within the VCN's address space. For a VNIC on a particular subnet of a VCN, the private overlay IP address assigned to the VNIC is an address from the contiguous range of overlay IP addresses allocated to the subnet.

[0093] In an embodiment, a compute instance may be optionally assigned additional overlay IP addresses in addition to the private overlay IP address, such as one or more public IP addresses if in a public subnet. These multiple addresses are assigned on the same VNIC or across multiple VNICs associated with the compute instance. However, each instance has a primary VNIC that is created during instance launch and associated with the overlay private IP address assigned to the instance, and this primary VNIC cannot be deleted. Additional VNICs, referred to as secondary VNICs, can be added to an existing instance in the same availability domain as the primary VNIC. All VNICs are in the same availability domain as the instance. The secondary VNICs can be in a subnet in the same VCN as the primary VNIC, or in a different subnet, either in the same VCN or in a different VCN.

[0094] Compute instances may optionally be assigned public IP addresses if they are in a public subnet. Subnets can be designed as either public or private subnets when the subnets are created. A private subnet means that resources in the subnet (e.g., compute instances) and associated VNICs cannot have public overlay IP addresses. A public subnet means that resources in the subnet and associated VNICs can have public IP addresses. Customers can specify subnets to exist in a single availability domain or across multiple availability domains within a region or realm.

[0095] As mentioned above, a VCN can be subdivided into one or more subnets. In one embodiment, a virtual router (VR) (referred to as a VCN VR or simply VR) configured for a VCN enables communication between subnets of the VCN. For a subnet in a VCN, the VR represents a logical gateway for that subnet that enables the subnet (i.e., the compute instances on that subnet) to communicate with endpoints on other subnets in the VCN and with other endpoints outside the VCN. A VCN VR is a logical entity that is configured to route traffic between VNICs in a VCN and a virtual gateway ("gateway") associated with the VCN. Gateways are further described below with respect to FIG. 6. A VCN VR is a layer 3 / IP layer concept. In one embodiment, there is one VCN VR for a VCN, which potentially has an infinite number of ports that are addressed by IP addresses, one port for each subnet of the VCN. Thus, the VCN VR has a different IP address for each subnet in the VCN to which the VCN VR is attached. The VRs are also connected to various gateways configured for the VCN. In some embodiments, an overlay IP address from a subnet's overlay IP address range is reserved for ports in the subnet's VCN VR. For example, consider a VCN with two subnets with associated address ranges 10.0 / 16 and 10.1 / 16, respectively. For the first subnet in the VCN with address range 10.0 / 16, an address from this range is reserved for ports in the subnet's VCN VR. In some cases, the first IP address from the range may be reserved for a VCN VR. For example, for a subnet with overlay IP address range 10.0 / 16, IP address 10.0.0.1 may be reserved for ports in the subnet's VCN VR.For a second subnet in the same VCN with address range 10.1 / 16, the VCN VR may have a port in that second subnet with IP address 10.1.0.1. The VCN VR has a different IP address for each of the subnets in the VCN.

[0096] In some other embodiments, each subnet in a VCN can have its own associated VR that is addressable by the subnet using a reserved or default IP address associated with the VR. The reserved or default IP address can be, for example, the first IP address from a range of IP addresses associated with the subnet. VNICs in a subnet can use this default or reserved IP address to communicate (e.g., send and receive packets) with the VR associated with the subnet. In such embodiments, a VR is an ingress / egress point for that subnet. A VR associated with a subnet in a VCN can communicate with other VRs associated with other subnets in the VCN. The VR can also communicate with a gateway associated with the VCN. The VR functions of a subnet are running on or performed by one or more NVDs that are running the VNIC functions of the VNICs in the subnet.

[0097] Routing tables, security rules, and DHCP options can be configured for a VCN. A route table is a virtual route table for a VCN that contains rules for routing traffic from subnets in the VCN to destinations outside the VCN by gateways or specially configured instances. A VCN's route table can be customized to control how packets are forwarded / routed to and from the VCN. DHCP options refer to configuration information that is automatically provided to an instance when the instance launches.

[0098] Security rules configured for a VCN represent the overlay firewall rules for the VCN. Security rules can include ingress and egress rules and can specify the type of traffic (based on protocol and port) that is allowed in and out of instances in the VCN. Customers can choose whether a given rule is stateful or stateless. For example, a customer can allow SSH traffic from anywhere to come into a set of instances by setting up a stateful ingress rule with source CIDR 0.0.0.0 / 0 and destination TCP port 22. Security rules can be implemented using network security groups or security lists. A network security group consists of a set of security rules that apply only to resources in that group. A security list, on the other hand, contains rules that apply to all resources in any subnet that uses the security list. A VCN can be provided with a default security list with default security rules. DHCP options configured for a VCN provide configuration information that is automatically provided to instances in the VCN when the instances launch.

[0099] In one embodiment, the configuration information of the VCN is determined and stored by the VCN control plane. The configuration information of the VCN may include, for example, information about the address ranges associated with the VCN, the subnets and associated information in the VCN, one or more VRs associated with the VCN, the compute instances and associated VNICs in the VCN, the NVDs performing various virtualized network functions (e.g., VNICs, VRs, gateways) associated with the VCN, state information of the VCN, and other VCN-related information. In one embodiment, the VCN distribution service publishes the configuration information stored by the VCN control plane, or a portion thereof, to the NVD. The distributed information can be used to update information (e.g., forwarding tables, routing tables, etc.) stored and used by the NVD to forward packets to and from the compute instances in the VCN.

[0100] In one embodiment, the creation of VCNs and subnets is handled by a VCN control plane (CP), and the launch of compute instances is handled by the compute control plane. The compute control plane is responsible for allocating physical resources for the compute instances, and then calls the VCN control plane to create and attach VNICs to the compute instances. The VCN CP also sends VCN data mappings to the VCN data plane, which is configured to perform packet forwarding and routing functions. In one embodiment, the VCN CP provides a distribution service that is responsible for providing updates to the VCN data plane. Examples of the VCN control plane are also shown in Figures 11, 12, 13, and 14 (see reference numbers 1116, 1216, 1316, and 1416) and described below.

[0101] A customer can create one or more VCNs using resources hosted by CSPI. Compute instances deployed on a customer VCN can communicate with multiple different endpoints. These endpoints can include endpoints hosted by CSPI and endpoints outside of CSPI.

[0102] Various different architectures for implementing cloud-based services using CSPI are shown in Figures 6, 7, 8, 9, 10, 11, 12, 13, and 15 and described below. Figure 6 is a high-level diagram of a distributed environment 600 illustrating an overlay or customer VCN hosted by CSPI according to an embodiment. The distributed environment shown in Figure 6 includes multiple components in an overlay network. The distributed environment 600 shown in Figure 6 is merely illustrative and is not intended to unduly limit the scope of the claimed embodiments. Many variations, alternatives, and modifications are possible. For example, in some implementations, the distributed environment shown in Figure 6 may have more or fewer systems or components than those shown in Figure 1, may combine two or more systems, or may have a different configuration or arrangement of systems.

[0103] As shown in the example depicted in FIG. 6, a distributed environment 600 includes a CSPI 601 that provides services and resources that a customer can subscribe to and use to build its virtual cloud network (VCN). In one embodiment, the CSPI 601 provides IaaS services to subscribing customers. Data centers in the CSPI 601 can be organized into one or more regions. One exemplary region, “Region US” 602, is shown in FIG. 6. A customer configures a customer VCN 604 in the region 602. A customer can deploy various compute instances on the VCN 604, where the compute instances may include virtual machines or bare metal instances. Example instances include applications, databases, load balancers, etc.

[0104] In the embodiment shown in FIG. 6, customer VCN 604 includes two subnets, "Subnet 1" and "Subnet 2," each with its own CIDR IP address range. In FIG. 6, the overlay IP address range of Subnet 1 is 10.0 / 16, and the address range of Subnet 2 is 10.1 / 16. VCN virtual router 605 represents the logical gateway of the VCN, enabling communication between the subnets of VCN 604 and with other endpoints outside the VCN. VCN VR 605 is configured to route traffic between VNICs in VCN 604 and the gateway associated with VCN 604. VCN VR 605 provides a port for each subnet of VCN 604. For example, VR 605 can provide a port with IP address 10.0.0.1 for Subnet 1 and a port with IP address 10.1.0.1 for Subnet 2.

[0105] Multiple compute instances may be deployed on each subnet, where the compute instances may be virtual machine instances and / or bare metal instances. The compute instances in a subnet may be hosted by one or more host machines in CSPI601. The compute instances join the subnet via a VNIC associated with the compute instance. For example, as shown in FIG. 6, compute instance C1 is part of subnet 1 via a VNIC associated with the compute instance. Similarly, compute instance C2 is part of subnet 1 via a VNIC associated with C2. Similarly, multiple compute instances, which may be virtual machine instances or bare metal instances, may be part of subnet 1. Through its associated VNIC, each compute instance is assigned a private overlay IP address and a MAC address. For example, in FIG. 6, compute instance C1 has an overlay IP address of 10.0.0.2 and a MAC address of M1, while compute instance C2 has a private overlay IP address of 10.0.0.3 and a MAC address of M2. Each compute instance in Subnet1, including compute instances C1 and C2, has a default route to VCN VR605 using IP address 10.0.0.1, which is the IP address of a port in VCN VR605 in Subnet1.

[0106] Subnet 2 may have multiple compute instances deployed thereon, including virtual machine instances and / or bare metal instances. For example, as shown in FIG. 6, compute instances D1 and D2 are part of subnet 2 via VNICs associated with the respective compute instances. In the embodiment shown in FIG. 6, compute instance D1 has an overlay IP address of 10.1.0.2 and a MAC address of MM1, while compute instance D2 has a private overlay IP address of 10.1.0.3 and a MAC address of MM2. Each compute instance in subnet 2, including compute instances D1 and D2, has a default route to VCN VR605 using IP address 10.1.0.1, which is the IP address of a port in VCN VR605 in subnet 2.

[0107] VCN A 604 may also include one or more load balancers. For example, a load balancer may be provided for a subnet and configured to load balance traffic across multiple compute instances on the subnet. A load balancer may also be provided to load balance traffic across subnets in the VCN.

[0108] A particular compute instance deployed on VCN 604 can communicate with a variety of different endpoints. These endpoints may include endpoints hosted by CSPI 700 and endpoints outside CSPI 700. Endpoints hosted by CSPI 601 may include endpoints on the same subnet as the particular compute instance (e.g., communication between two compute instances in subnet 1), endpoints on a different subnet but within the same VCN (e.g., communication between a compute instance in subnet 1 and a compute instance in subnet 2), endpoints in a different VCN in the same region (e.g., communication between a compute instance in subnet 1 and an endpoint in a VCN in the same region 606 or 610, communication between a compute instance in subnet 1 and an endpoint in a service network 610 in the same region), or endpoints in a VCN in a different region (e.g., communication between a compute instance in subnet 1 and an endpoint in a VCN in a different region 608). Compute instances in a subnet hosted by CSPI 601 may also communicate with endpoints not hosted by CSPI 601 (i.e., outside CSPI 601). These external endpoints include endpoints within a customer's on-premise network 616, endpoints within other remote cloud hosted networks 618, public endpoints 614 accessible via public networks such as the Internet, and other endpoints.

[0109] Communication between compute instances on the same subnet is facilitated using VNICs associated with the source and destination compute instances. For example, compute instance C1 in subnet 1 may want to send a packet to compute instance C2 in subnet 1. For a packet originating from a source compute instance whose destination is another compute instance in the same subnet, the packet is first processed by the VNIC associated with the source compute instance. The processing performed by the VNIC associated with the source compute instance may include determining the packet's destination information from the packet header, identifying any policies (e.g., security lists) configured for the VNIC associated with the source compute instance, determining the packet's next hop, performing any encapsulation / decapsulation functions as necessary, and then forwarding / routing the packet to the next hop with the goal of facilitating communication of the packet to its intended destination. When the destination compute instance is in the same subnet as the source compute instance, the VNIC associated with the source compute instance is configured to identify the VNIC associated with the destination compute instance and forward the packet to that VNIC for processing. At this time, the VNIC associated with the destination compute instance is executed and forwards the packet to the destination compute instance.

[0110] For a packet to be communicated from a compute instance in a subnet to an endpoint in a different subnet in the same VCN, the communication is facilitated by the VNICs and VCN VRs associated with the source and destination compute instances. For example, if compute instance C1 in subnet 1 of FIG. 6 wants to send a packet to compute instance D1 in subnet 2, the packet is first processed by the VNIC associated with compute instance C1. The VNIC associated with compute instance C1 is configured to route the packet to VCN VR 605 using the VCN VR's default route or port 10.0.0.1. VCN VR 605 is configured to route the packet to subnet 2 using port 10.1.0.1. The packet is then received and processed by the VNIC associated with D1, which forwards the packet to compute instance D1.

[0111] For packets to be communicated from a compute instance in VCN 604 to an endpoint outside VCN 604, the communication is facilitated by a VNIC associated with the source compute instance, VCN VR 605, and a gateway associated with VCN 604. One or more types of gateways may be associated with VCN 604. A gateway is an interface between a VCN and another endpoint, where the other endpoint is outside the VCN. A gateway is a layer 3 / IP layer concept that allows a VCN to communicate with endpoints outside the VCN. Thus, a gateway facilitates traffic flow between a VCN and other VCNs or networks. Various different types of gateways may be configured for a VCN to facilitate different types of communication with different types of endpoints. Depending on the gateway, the communication may be over a public network (e.g., the Internet) or a private network. Various communication protocols may be used for these communications.

[0112] For example, compute instance C1 may desire to communicate with an endpoint outside of VCN 604. The packet may first be processed by a VNIC associated with source compute instance C1. The VNIC processing determines that the packet's destination is outside of Subnet 1 of C1. The VNIC associated with C1 may forward the packet to VCN VR 605 of VCN 604. VCN VR 605 then processes the packet and, as part of the processing, determines a particular gateway associated with VCN 604 as the next hop for the packet based on the packet's destination. VCN VR 605 may then forward the packet to the particular identified gateway. For example, if the destination is an endpoint within a customer's on-premise network, the packet may be forwarded by VCN VR 605 to a dynamic routing gateway (DRG) gateway 622 configured for VCN 604. The packet may then be forwarded from the gateway to the next hop to facilitate communication of the packet to its final intended destination.

[0113] Various different types of gateways may be configured for a VCN. Examples of gateways that may be configured for a VCN are shown in FIG. 6 and described below. Examples of gateways associated with a VCN are also shown in FIG. 11, FIG. 12, FIG. 13, and FIG. 14 (e.g., gateways referenced by reference numbers 1134, 1136, 1138, 1234, 1236, 1238, 1334, 1336, 1338, 1434, 1436, and 1438) and described below. As shown in the embodiment shown in FIG. 6, a dynamic routing gateway (DRG) 622 may be added to or associated with a customer VCN 604 to provide a path for private network traffic communication between the customer VCN 604 and another endpoint, where the other endpoint may be a customer's on-premise network 616, a VCN 608 in a different region of the CSPI 601, or another remote cloud network 618 not hosted by the CSPI 601. The customer on-premise network 616 may be a customer network or customer data center that is built using the customer's resources. Access to the customer on-premise network 616 is generally very restricted. For a customer that has both the customer on-premise network 616 and one or more VCNs 604 deployed or hosted in the cloud by CSPI 601, the customer may want its on-premise network 616 and its cloud-based VCNs 604 to be able to communicate with each other. This allows the customer to build an extended hybrid environment that encompasses the customer's VCNs 604 hosted by CSPI 601 and its on-premise network 616. The DRG 622 enables this communication. To enable such communication, a communication channel 624 is set up, where one endpoint of the channel is the customer on-premise network 616 and the other endpoint is CSPI 601, connected to the customer VCN 604. The communication channel 624 may be over a public or private communication network, such as the Internet.A variety of different communication protocols may be used, such as IPsec VPN technology over a public communication network such as the Internet, Oracle's FastConnect technology that uses a private network instead of a public network, etc. A device or equipment in the customer on-premise network 616 that forms one endpoint of the communication channel 624 is referred to as a customer premises equipment (CPE), such as CPE 626 shown in Figure 6. On the CSPI 601 side, the endpoint may be a host machine running DRG 622.

[0114] In one embodiment, a remote peering connection (RPC) can be added to a DRG, allowing a customer to peer one VCN with another VCN in a different region. Using such an RPC, a customer VCN 604 can connect with a VCN 608 in another region using a DRG 622. The DRG 622 can also be used to communicate with other remote cloud networks 618 not hosted by CSPI 601, such as the Microsoft Azure cloud, the Amazon AWS cloud, etc.

[0115] As shown in Figure 6, an Internet Gateway (IGW) 620 can be configured for a customer VCN 604 to enable compute instances on VCN 604 to communicate with public endpoints 614 accessible over a public network, such as the Internet. The IGW 620 is a gateway that connects a VCN to a public network, such as the Internet. The IGW 620 enables a public subnet in a VCN, such as VCN 604 (where resources in the public subnet have public overlay IP addresses) to directly access a public endpoint 612 on a public network 614, such as the Internet. The IGW 620 can be used to initiate connections from a subnet in VCN 604 or from the Internet.

[0116] A network address translation (NAT) gateway 628 can be configured for a customer's VCN 604 to allow cloud resources in the customer's VCN that do not have dedicated public overlay IP addresses to access the Internet, and does so without exposing those resources to a direct inbound Internet connection (e.g., an L4-L7 connection). This allows private subnets in the VCN, such as Private Subnet 1 in VCN 604, to have private access to public endpoints on the Internet. With a NAT gateway, connections can only be initiated from the private subnet to the public Internet, not from the Internet to the private subnet.

[0117] In one embodiment, a service gateway (SGW) 626 can be configured for a customer VCN 604 and provides a path for private network traffic between the VCN 604 and supported service endpoints in the service network 610. In one embodiment, the service network 610 can be provided by a CSP and can provide a variety of services. One example of such a service network is Oracle's service network, which provides a variety of services that can be used by a customer. For example, a compute instance (e.g., a database system) in a private subnet of the customer VCN 604 can back up data to a service endpoint (e.g., object storage) without needing a public IP address or access to the Internet. In one embodiment, a VCN can have only one SGW and connections can only be initiated from a subnet in the VCN, not from the service network 610. If a VCN is peered with another VCN, resources in the other VCN cannot access the SGW. Resources in an on-premises network connected to a VCN by FastConnect or VPN Connect can also use a service gateway configured for that VCN.

[0118] In one embodiment, the SGW 626 uses the concept of a service classless inter-domain routing (CIDR) label, which is a string that represents all regional public IP address ranges for a service or group of services of interest. A customer uses the service CIDR label when configuring the SGW and associated route rules to control traffic to the service. A customer can optionally utilize the service CIDR label when configuring security rules without having to adjust those security rules if the service's public IP addresses change in the future.

[0119] A local peering gateway (LPG) 632 is a gateway that can be added to a customer VCN 604, allowing the VCN 604 to peer with another VCN in the same region. Peering means that the VCNs communicate using private IP addresses without the traffic traversing a public network, such as the Internet, or routing the traffic through the customer's on-premises network 616. In a preferred embodiment, a VCN has a separate LPG for each peering it establishes. Local peering or VCN peering is a common practice used to establish network connections between different applications or infrastructure management functions.

[0120] A service provider, such as a provider of services in service network 610, can provide access to services using different access models. According to a public access model, the service may be exposed as a public endpoint that is publicly accessible by a compute instance in the customer VCN over a public network such as the Internet, or it may be privately accessible through SGW 626. According to a specific private access model, the service is made accessible as a private IP endpoint in a private subnet in the customer's VCN. This is referred to as private endpoint (PE) access and allows service providers to expose their services as instances in the customer's private network. A private endpoint resource represents a service in the customer's VCN. Each PE appears as a VNIC (referred to as a PE-VNIC with one or more private IPs) in a subnet selected by the customer in the customer's VCN. Thus, the PE provides a way to present a service in a private customer VCN subnet using a VNIC. Because the endpoint is exposed as a VNIC, all the features associated with a VNIC, such as routing rules, security lists, etc., are made available to the PE VNIC at this point.

[0121] A service provider can register its services to enable access through the PE. Providers can associate policies with services, which constrain the visibility of the service to a customer tenancy. Providers can register multiple services under a single virtual IP address (VIP), especially for multi-tenant services. There can be multiple such private endpoints (in multiple VCNs) representing the same service.

[0122] Compute instances in the private subnet can then access the service using the private IP address of the PE VNIC or the service DNS name. Compute instances in the customer VCN can access the service by sending traffic to the private IP address of the PE in the customer VCN. A private access gateway (PAGW) 630 is a gateway resource that can be attached to a service provider VCN (e.g., a VCN in the service network 610) that acts as the ingress / egress point for all traffic from / to the customer subnet private endpoints. The PAGW 630 allows the provider to scale the number of PE connections without utilizing its internal IP address resources. The provider only needs to configure one PAGW for any number of services registered in a single VCN. The provider can represent the services as private endpoints in multiple VCNs for one or more customers. From the customer's perspective, the PE VNIC appears to be attached to the service with which the customer wants to interact, instead of being attached to the customer's instance. Traffic destined for the private endpoint is routed to the service through the PAGW 630. These are referred to as Customer-to-Service Private Connections (C2S connections).

[0123] The PE concept can also be used to extend private access for services to a customer's on-premises network and datacenter by allowing traffic to flow through a FastConnect / IPsec link and a private endpoint in the customer's VCN. Private access for services can also be extended to a customer's peered VCN by allowing traffic to flow between LPG 632 and a PE in the customer's VCN.

[0124] A customer can control routing in a VCN at the subnet level, so the customer can specify which subnets of the customer's VCN, such as VCN 604, use each gateway. The VCN's route table is used to determine whether traffic is allowed to exit the VCN through a particular gateway. For example, in a particular case, the route table of a public subnet in customer VCN 604 can send non-local traffic through IGW 620. The route table of a private subnet in the same customer VCN 604 can send traffic destined for a CSP service through SGW 626. All remaining traffic can be sent through NAT gateway 628. The route table controls only traffic that exits the VCN.

[0125] Security lists associated with a VCN are used to control traffic that comes into the VCN through a gateway via an incoming connection. All resources within a subnet use the same route table and security lists. Security lists can be used to control the specific types of traffic that are allowed into and out of instances within a subnet of a VCN. Security list rules can include ingress (incoming) and egress (outgoing) rules. For example, ingress rules can specify the allowed source address ranges, while egress rules can specify the allowed destination address ranges. Security rules can specify a particular protocol (e.g., TCP, ICMP), a particular port (e.g., 22 for SSH, 3389 for Windows RDP), etc. In some embodiments, the instance's operating system can enforce its own firewall rules that are aligned with the security list rules. Rules can be stateful (e.g., connections are tracked and responses are automatically allowed without an explicit security list rule for the response traffic) or stateless.

[0126] Access from a customer VCN (i.e., by resources or compute instances deployed on VCN 604) can be categorized as public access, private access, or dedicated access. Public access refers to an access model in which public IP addresses or NATs are used to access public endpoints. Private access allows customer workloads (e.g., resources in a private subnet) in VCN 604 with private IP addresses to access services without traversing a public network such as the Internet. In one embodiment, CSPI 601 allows customer VCN workloads with private IP addresses to access (public service endpoints of) services using a service gateway. Thus, the service gateway provides a private access model by establishing a virtual link between the customer's VCN and the service's endpoints that exist outside the customer's private network.

[0127] Additionally, CSPI can provide dedicated public access using technologies such as FastConnect public peering, where customer on-premises instances can use a FastConnect connection to access one or more services in the customer VCN without traversing a public network such as the Internet. CSPI can also provide dedicated private access using FastConnect private peering, where customer on-premises instances with private IP addresses can use a FastConnect connection to access customer VCN workloads. FastConnect is a network connection alternative to using the public Internet to connect a customer on-premises network to CSPI and its services. FastConnect provides an easy, elastic, and economical way to create a dedicated private connection with higher bandwidth options and a more reliable and consistent networking experience compared to Internet-based connections.

[0128] FIG. 6 and the accompanying description above describe various virtualization components in an exemplary virtual network. As mentioned above, a virtual network is built on an underlying physical or infrastructure network. FIG. 7 illustrates a simplified architecture diagram of physical components in a physical network in CSPI700 that provides an underlying layer of a virtual network, according to an embodiment. As illustrated, CSPI700 provides a distributed environment including components and resources (e.g., compute, memory, and networking resources) provided by a cloud service provider (CSP). These components and resources are used to provide cloud services (e.g., IaaS services) to subscribing customers, i.e., customers who subscribe to one or more services provided by the CSP. Based on the services to which the customer subscribes, a subset of the resources (e.g., compute, memory, and networking resources) of CSPI700 is provisioned to the customer. The customer can then build their own cloud-based (i.e., CSPI-hosted) customizable private virtual network using the physical compute, memory, and networking resources provided by CSPI700. As previously indicated, these customer networks are referred to as Virtual Cloud Networks (VCNs). On these customer VCNs, customers can deploy one or more customer resources, such as compute instances. The compute instances can be in the form of virtual machines, bare metal instances, etc. CSPI 700 provides an infrastructure and a set of complementary cloud services that enable customers to build and run a wide variety of applications and services in a highly available hosted environment.

[0129] In the exemplary embodiment shown in FIG. 7, the physical components of CSPI 700 include one or more physical host machines or servers (e.g., 702, 706, 708), network virtualization devices (NVDs) (e.g., 710, 712), top-of-rack (TOR) switches (e.g., 714, 716), and physical networks (e.g., 718), as well as switches within physical network 718. The physical host machines or servers can host and execute various compute instances that participate in one or more subnets of the VCN. The compute instances can include virtual machine instances or bare metal instances. For example, the various compute instances shown in FIG. 6 can be hosted by the physical host machines shown in FIG. 7. The virtual machine compute instances in the VCN can be executed by one host machine or by multiple different host machines. The physical host machines can also host virtual host machines, container-based hosts or functions, and the like. The VNICs and VCN VRs shown in FIG. 6 can be executed by the NVDs shown in FIG. 7. The gateway shown in FIG. 6 may be executed by a host machine and / or a NVD shown in FIG.

[0130] A host machine or server may run a hypervisor (also referred to as a virtual machine monitor or VMM) that creates and enables a virtualized environment on the host machine. Virtualization or a virtualized environment facilitates cloud-based computing. One or more compute instances may be created, executed, and managed on a host machine by a hypervisor on the host machine. The hypervisor on the host machine enables the physical computing resources (e.g., compute, memory, and networking resources) of the host machine to be shared among the various compute instances executed by the host machine.

[0131] For example, as shown in FIG. 7, host machines 702 and 708 run hypervisors 760 and 766, respectively. These hypervisors may be implemented using software, firmware, or hardware, or a combination thereof. Typically, a hypervisor is a process or software layer that sits on top of the host machine's operating system (OS), running on the host machine's hardware processor. A hypervisor provides a virtualized environment by allowing the host machine's physical computing resources (e.g., processing resources such as processors / cores, memory resources, networking resources, etc.) to be shared among various virtual machine computing instances executed by the host machine. For example, in FIG. 7, hypervisor 760 can sit on top of the host machine's OS and allow the host machine's 702's computing resources (e.g., processing, memory, and networking resources) to be shared among computing instances (e.g., virtual machines) executed by the host machine 702. A virtual machine can have its own operating system (referred to as a guest operating system), which may be the same as or different from the host machine's OS. The operating system of a virtual machine executed by a host machine may be the same as or different from the operating system of another virtual machine executed by the same host machine. Thus, the hypervisor allows multiple operating systems to run in parallel with each other while sharing the same computing resources of the host machine. The host machines shown in FIG. 7 may have the same or different types of hypervisors.

[0132] A compute instance can be a virtual machine instance or a bare metal instance. In Figure 7, compute instance 768 on host machine 702 and compute instance 774 on host machine 708 are examples of virtual machine instances. Host machine 706 is an example of a bare metal instance provided to a customer.

[0133] In some cases, an entire host machine may be provisioned to a single customer, and all of the one or more compute instances (either virtual machines or bare metal instances) hosted by that host machine belong to that same customer. In other cases, a host machine may be shared among multiple customers (i.e., multiple tenants). In such a multi-tenancy scenario, a host machine may host virtual machine compute instances that belong to different customers. These compute instances may be members of different VCNs for different customers. In some embodiments, bare metal compute instances are hosted by bare metal servers without a hypervisor. When a bare metal compute instance is provisioned, a single customer or tenant maintains control of the physical CPU, memory, and network interfaces of the host machine that hosts the bare metal instance, and the host machine is not shared with other customers or tenants.

[0134] As previously mentioned, each compute instance that is part of a VCN is associated with a VNIC that enables the compute instance to be a member of a subnet of the VCN. The VNIC associated with a compute instance facilitates communication of packets or frames to and from the compute instance. When a compute instance is created, a VNIC is associated with the compute instance. In one embodiment, for a compute instance executed by a host machine, the VNIC associated with the compute instance is executed by an NVD connected to the host machine. For example, in FIG. 7, host machine 702 executes virtual machine compute instance 768 associated with VNIC 776, which is executed by NVD 710 connected to host machine 702. As another example, bare metal instance 772 hosted by host machine 706 is associated with VNIC 780, which is executed by NVD 712 connected to host machine 706. As yet another example, VNIC 784 is associated with compute instance 774 executed by host machine 708, which is executed by NVD 712 connected to host machine 708.

[0135] For a compute instance hosted by a host machine, the NVD connected to that host machine also runs VCN VRs corresponding to the VCNs of which the compute instance is a member. For example, in the embodiment shown in Figure 7, NVD 710 runs VCN VR 777 corresponding to the VCN of which compute instance 768 is a member. NVD 712 may also run one or more VCN VRs 783 corresponding to the VCNs corresponding to the compute instances hosted by host machines 706 and 708.

[0136] A host machine may include one or more network interface cards (NICs) that allow the host machine to be connected to other devices. The NICs on a host machine may provide one or more ports that allow the host machine to be communicatively connected to another device. For example, a host machine may be connected to an NVD using one or more ports (or interfaces) provided on the host machine and the NVD. A host machine may also be connected to other devices, such as another host machine.

[0137] 7, host machine 702 is connected to NVD 710 using link 720 that extends between port 734 provided by NIC 732 of host machine 702 and port 736 of NVD 710. Host machine 706 is connected to NVD 712 using link 724 that extends between port 746 provided by NIC 744 of host machine 706 and port 748 of NVD 712. Host machine 708 is connected to NVD 712 using link 726 that extends between port 752 provided by NIC 750 of host machine 708 and port 754 of NVD 712.

[0138] The NVDs are then connected via communication links to top-of-rack (TOR) switches, which are connected to a physical network 718 (also referred to as a switch fabric). In one embodiment, the links between the host machines and the NVDs and between the NVDs and the TOR switches are Ethernet links. For example, in FIG. 7, NVDs 710 and 712 are connected to 1126 TOR switches 714 and 716 using links 728 and 730, respectively. In one embodiment, links 720, 724, 726, 728, and 730 are Ethernet links. The collection of host machines and NVDs connected to a TOR may be referred to as a rack.

[0139] The physical network 718 provides a communications fabric that allows the TOR switches to communicate with each other. The physical network 718 can be a multi-tiered network. In one embodiment, the physical network 718 is a multi-tiered Clos network of switches, with the TOR switches 714 and 716 representing leaf-level nodes of the multi-tiered multi-node physical switching network 718. Different Clos network configurations are possible, including, but not limited to, two-tier networks, three-tier networks, four-tier networks, five-tier networks, and generally "n" tiered networks. An example of a Clos network is shown in FIG. 10 and described below.

[0140] A variety of different connection configurations between host machines and NVDs are possible, such as one-to-one, many-to-one, one-to-many, etc. In a one-to-one configuration embodiment, each host machine is connected to its own separate NVD. For example, in FIG. 7, host machine 702 is connected to NVD 710 via NIC 732 of host machine 702. In a many-to-one configuration, multiple host machines are connected to one NVD. For example, in FIG. 7, host machines 706 and 708 are connected to the same NVD 712 via NICs 744 and 750, respectively.

[0141] In a one-to-many configuration, one host machine is connected to multiple NVDs. Figure 8 shows an example in CSPI 800 where a host machine is connected to multiple NVDs. As shown in Figure 8, a host machine 802 includes a network interface card (NIC) 804 that includes multiple ports 806 and 808. The host machine 800 is connected to a first NVD 810 via port 806 and link 820, and to a second NVD 812 via port 808 and link 822. The ports 806 and 808 may be Ethernet ports, and the links 820 and 822 between the host machine 802 and the NVDs 810 and 812 may be Ethernet links. The NVD 810 is then connected to a first TOR switch 814, and the NVD 812 is connected to a second TOR switch 816. The links between the NVDs 810 and 812 and the TOR switches 814 and 816 may be Ethernet links. TOR switches 814 and 816 represent tier 0 switching devices within a multi-tiered physical network 818 .

[0142] 8 provides two separate physical network paths from the physical switch network 818 to the host machine 802 and from the host machine 802 to the physical switch network 818: a first path that traverses TOR switch 814-NVD 810-host machine 802, and a second path that traverses TOR switch 816-NVD 812-host machine 802. These separate paths provide increased availability (referred to as high availability) of the host machine 802. If there is a problem with one of the paths (e.g., one link in the path fails) or devices (e.g., a particular NVD is not functioning), the other path can be used for communication to / from the host machine 802.

[0143] In the configuration shown in Figure 8, the host machine is connected to two different NVDs using two different ports provided by the host machine's NIC. In other embodiments, the host machine may include multiple NICs allowing the host machine to connect to multiple NVDs.

[0144] Referring back to Figure 7, an NVD is a physical device or component that implements one or more network and / or storage virtualization functions. An NVD can be any device that has one or more processing units (e.g., a CPU, a network processing unit (NPU), an FPGA, a packet processing pipeline, etc.), memory including cache, and ports. Various virtualization functions can be implemented by software / firmware executed by the one or more processing units of the NVD.

[0145] The NVD can be implemented in a variety of different forms. For example, in one embodiment, the NVD is implemented as an interface card, referred to as a smartNIC or intelligent NIC, with a processor built into the board. A smartNIC is a separate device from the NIC on the host machine. In FIG. 7, the NVDs 710 and 712 can be implemented as smartNICs connected to the host machine 702, and the host machines 706 and 708, respectively.

[0146] However, smartNIC is only one example of an NVD implementation. Various other implementations are possible. For example, in some other embodiments, the NVD or one or more functions performed by the NVD may be incorporated into or performed by one or more host machines, one or more TOR switches, and other components of CSPI700. For example, the NVD may be embodied in a host machine, where the functions performed by the NVD are performed by the host machine. As another example, the NVD may be part of a TOR switch, or the TOR switch may be configured to perform the functions performed by the NVD that enable the TOR switch to perform various complex packet transformations used for public clouds. A TOR that performs the functions of the NVD may be referred to as a smart TOR. In still other embodiments where customers are provided with virtual machine (VM) instances rather than bare metal (BM) instances, the functions performed by the NVD may be implemented inside the hypervisor of the host machine. In some other embodiments, some of the functions of the NVD may be offloaded to a centralized service running on a fleet of host machines.

[0147] In some embodiments, such as when implemented as a smartNIC as shown in FIG. 7, the NVD may comprise multiple physical ports that allow it to be connected to one or more host machines and one or more TOR switches. Ports on the NVD can be classified as host-side ports (also referred to as "south ports") or network-side or TOR-side ports (also referred to as "north ports"). The host-side ports of the NVD are the ports used to connect the NVD to the host machines. Examples of host-side ports in FIG. 7 include port 736 on the NVD 710 and ports 748 and 754 on the NVD 712. The network-side ports of the NVD are the ports used to connect the NVD to the TOR switches. Examples of network-side ports in FIG. 7 include port 756 on the NVD 710 and port 758 on the NVD 712. As shown in FIG. 7, the NVD 710 is connected to the TOR switch 714 using a link 728 that extends from port 756 of the NVD 710 to the TOR switch 714. Similarly, the NVD 712 is connected to the TOR switch 716 using a link 730 that extends from a port 758 of the NVD 712 to the TOR switch 716 .

[0148] The NVD can receive packets and frames from a host machine (e.g., packets and frames generated by a compute instance hosted by the host machine) via a host-side port, perform necessary packet processing, and then forward the packets and frames to a TOR switch via the NVD's network-side port. The NVD can receive packets and frames from a TOR switch via the NVD's network-side port, and perform necessary packet processing, and then forward the packets and frames to a host machine via the NVD's host-side port.

[0149] In an embodiment, there may be multiple ports and associated links between the NVD and the TOR switch. These ports and links may be aggregated to form a link aggregator group (referred to as a LAG) of multiple ports or links. Link aggregation allows multiple physical links between two endpoints (e.g., between the NVD and the TOR switch) to be treated as a single logical link. All physical links within a given LAG may operate in full-duplex mode at the same speed. LAGs help increase the bandwidth and reliability of the connection between the two endpoints. If one of the physical links in the LAG fails, the traffic is dynamically and transparently reassigned to one of the other physical links in the LAG. The aggregated physical link delivers higher bandwidth than each individual link. Multiple ports associated with a LAG are treated as a single logical port. Traffic may be load-balanced across the multiple physical links of the LAG. One or more LAGs may be configured between the two endpoints. The two endpoints may be between the NVD and the TOR switch, between a host machine and the NVD, etc.

[0150] The NVD implements or performs network virtualization functions. These functions are performed by software / firmware executed by the NVD. Examples of network virtualization functions include, but are not limited to, packet encapsulation and decapsulation functions, functions for creating VCN networks, functions for implementing network policies such as VCN security list (firewall) functions, functions for facilitating routing and forwarding of packets to and from compute instances in the VCN, etc. In one embodiment, when a packet is received, the NVD is configured to execute a packet processing pipeline to process the packet and determine how the packet is forwarded or routed. As part of this packet processing pipeline, the NVD can execute one or more virtual functions associated with the overlay network, such as running VNICs associated with compute instances in the VCN, running virtual routers (VRs) associated with the VCN, encapsulating and decapsulating packets to facilitate forwarding or routing within the virtual network, running certain gateways (e.g., local peering gateways), implementing security lists, network security groups, network address translation (NAT) functions (e.g., translating public IPs to private IPs per host), throttling functions, and other functions.

[0151] In one embodiment, the packet processing data path in the NVD may include multiple packet pipelines, each consisting of a series of packet transformation stages. In one embodiment, when a packet is received, it is parsed and classified into a single pipeline. The packet is then processed linearly from one stage to another until the packet is dropped or sent out on an interface of the NVD. These stages provide basic functional packet processing building blocks (e.g., header validation, throttling enforcement, insertion of new layer 2 headers, L4 firewall enforcement, VCN encapsulation / decapsulation, etc.), such that new pipelines can be constructed by composing existing stages, and new functionality can be added by creating new stages and inserting them into existing pipelines.

[0152] The NVD can implement both control plane and data plane functions corresponding to the control and data planes of the VCN. Examples of the VCN control plane are also shown in Figures 11, 12, 13, and 14 (see reference numbers 1116, 1216, 1316, and 1416) and described below. Examples of the VCN data plane are also shown in Figures 11, 12, 13, and 14 (see reference numbers 1118, 1218, 1318, and 1418) and described below. The control plane functions include functions used to configure the network (e.g., setting up routes and route tables, configuring VNICs, etc.) that control how data should be forwarded. In one embodiment, a VCN control plane is provided that centrally computes all overlay-to-substrate mappings and publishes them to virtual network edge devices such as the NVD and various gateways such as DRGs, SGWs, IGWs, etc. Firewall rules can also be published using the same mechanism. In one embodiment, the NVD obtains only mappings that are relevant to the NVD. The data plane functions include functionality for the actual routing / forwarding of packets based on the configurations set up using the control plane. The VCN data plane is implemented by encapsulating customer network packets before they traverse the underlying network. The encapsulation / decapsulation functions are implemented on the NVD. In one embodiment, the NVD is configured to intercept all network packets entering and leaving the host machine and perform the network virtualization functions.

[0153] As indicated above, the NVD performs various virtualization functions including VNICs and VCN VRs. The NVD may perform VNICs associated with compute instances hosted by one or more host machines connected to the VNICs. For example, as shown in FIG. 7, the NVD 710 performs the functions of a VNIC 776 associated with a compute instance 768 hosted by a host machine 702 connected to the NVD 710. As another example, the NVD 712 performs VNICs 780 associated with a bare metal compute instance 772 hosted by a host machine 706 and VNICs 784 associated with a compute instance 774 hosted by a host machine 708. The host machines may host compute instances belonging to different VCNs that belong to different customers, and the NVDs connected to the host machines may perform VNICs (i.e., perform VNIC-related functions) corresponding to the compute instances.

[0154] NVDs also run VCN virtual routers corresponding to the VCNs of compute instances. For example, in the embodiment shown in FIG. 7, NVD 710 runs VCN VR 777 corresponding to the VCN to which compute instance 768 belongs. NVD 712 runs one or more VCN VRs 783 corresponding to one or more VCNs to which compute instances hosted by host machines 706 and 708 belong. In one embodiment, a VCN VR corresponding to that VCN is run by all NVDs connected to a host machine that hosts at least one compute instance that belongs to that VCN. If a host machine hosts compute instances that belong to different VCNs, the NVDs connected to that host machine may run VCN VRs corresponding to those different VCNs.

[0155] In addition to the VNICs and VCN VRs, the NVD may include one or more hardware components that run various software (e.g., daemons) and facilitate various network virtualization functions performed by the NVD. For simplicity, these various components are grouped together as a "packet processing component" as shown in FIG. 7. For example, the NVD 710 includes a packet processing component 786, and the NVD 712 includes a packet processing component 788. For example, the packet processing component of the NVD may include a packet processor configured to interact with the ports and hardware interfaces of the NVD to monitor all packets received by and communicated using the NVD and to store network information. The network information may include, for example, network flow information that identifies different network flows handled by the NVD on a per flow information (e.g., per flow statistics) basis. In an embodiment, the network flow information may be stored on a per VNIC basis. The packet processor may implement a stateful NAT and an L4 firewall (FW) as well as perform per packet operations. As another example, the packet processing component may include a replication agent configured to replicate information stored by the NVD to one or more different replication target stores. As yet another example, the packet processing component may include a logging agent configured to perform logging functions for the NVD. The packet processing component may also include software for monitoring the performance and health of the NVD, and possibly also the status and health of other components connected to the NVD.

[0156] FIG. 6 illustrates components of an exemplary virtual or overlay network including a VCN, a subnet in the VCN, compute instances deployed on the subnet, VNICs associated with the compute instances, VRs for the VCN, and a set of gateways configured for the VCN. The overlay components illustrated in FIG. 6 may be executed or hosted by one or more of the physical components illustrated in FIG. 7. For example, the compute instances in the VCN may be executed or hosted by one or more host machines illustrated in FIG. 7. For a compute instance hosted by a host machine, the VNICs associated with that compute instance are typically executed by the NVD connected to that host machine (i.e., the VNIC functionality is provided by the NVD connected to that host machine). The VCN VR functionality of the VCN is executed by all NVDs connected to the host machines that host or execute the compute instances that are part of that VCN. The gateways associated with a VCN may be executed by one or more different types of NVDs. For example, some gateways may be executed by smartNICs, while other gateways may be executed by one or more host machines or other implementations of NVDs.

[0157] As described above, a compute instance in a customer VCN can communicate with a variety of different endpoints, where the endpoints can be in the same subnet as the source compute instance, in a different subnet but in the same VCN as the source compute instance, or the endpoints can be outside the VCN of the source compute instance. These communications are facilitated using VNICs associated with the compute instances, VCN VRs, and gateways associated with the VCN.

[0158] For communication between two compute instances on the same subnet within a VCN, the communication is facilitated using VNICs associated with the source and destination compute instances. The source and destination compute instances may be hosted by the same host machine or may be hosted by different host machines. A packet originating from a source compute instance may be forwarded from the host machine hosting the source compute instance to an NVD connected to that host machine. On the NVD, the packet is processed using a packet processing pipeline, which may include execution of a VNIC associated with the source compute instance. Because the destination endpoint of the packet is within the same subnet, execution of the VNIC associated with the source compute instance results in the packet being forwarded to an NVD that executes a VNIC associated with the destination compute instance, which then processes the packet and forwards it to the destination compute instance. The VNICs associated with the source and destination compute instances may be executed on the same NVD (e.g., when both the source and destination compute instances are hosted by the same host machine) or may be executed on different NVDs (e.g., when the source and destination compute instances are hosted by different host machines that are connected to different NVDs). The VNIC can use the routing / forwarding tables stored by the NVD to determine the next hop for a packet.

[0159] To allow packets to be communicated from a compute instance in a subnet to an endpoint in a different subnet in the same VCN, packets originating from a source compute instance are communicated from a host machine hosting the source compute instance to an NVD connected to that host machine. On the NVD, the packets are processed using a packet processing pipeline that may include the execution of one or more VNICs and VRs associated with the VCN. For example, as part of the packet processing pipeline, the NVD executes or invokes functions corresponding to the VNICs associated with the source compute instance (also referred to as executing the VNICs). The functions performed by the VNICs may include looking at the VLAN tag on the packet. Because the packet destination is outside the subnet, the VCN VR functions are then invoked and executed by the NVD. The VCN VR then routes the packet to the NVD that executes the VNICs associated with the destination compute instance. The VNICs associated with the destination compute instance then processes and forwards the packet to the destination compute instance. The VNICs associated with the source and destination compute instances may run on the same NVD (e.g., when both the source and destination compute instances are hosted by the same host machine) or may run on different NVDs (e.g., when the source and destination compute instances are hosted by different host machines that are connected to different NVDs).

[0160] If the destination of the packet is outside the VCN of the source compute instance, the packet originating from the source compute instance is communicated from the host machine hosting the source compute instance to the NVD connected to that host machine. The NVD runs the VNIC associated with the source compute instance. Because the destination endpoint of the packet is outside the VCN, the packet is then processed by the VCN VR of that VCN. The NVD invokes a VCN VR function, which results in the packet being forwarded to the NVD running the appropriate gateway associated with the VCN. For example, if the destination is an endpoint in a customer's on-premise network, the packet can be forwarded by the VCN VR to the NVD running the DRG gateway configured for the VCN. The VCN VR can be run on the same NVD as the NVD running the VNIC associated with the source compute instance, or by a different NVD. The gateway may be run by the NVD, which may be a smartNIC, a host machine, or other NVD implementation. The packet can then be processed by the gateway and forwarded to the next hop that facilitates communication of the packet to its final intended destination. 7, a packet originating from compute instance 768 may be communicated from host machine 702 over link 720 (using NIC 732) to NVD 710. On NVD 710, VNIC 776 is invoked because this is the VNIC associated with the source compute instance 768. VNIC 776 is configured to examine encapsulation information in the packet, determine a next hop to forward the packet to with the goal of facilitating communication of the packet to its intended destination endpoint, and then forward the packet to the determined next hop.

[0161] A particular compute instance deployed on a VCN can communicate with a variety of different endpoints. These endpoints may include endpoints hosted by CSPI700 and endpoints outside of CSPI700. The endpoints hosted by CSPI700 may include instances in the same VCN or other VCNs, which may be the customer's VCN or may be a VCN that does not belong to the customer. Communications between endpoints hosted by CSPI700 may be performed over physical network 718. Compute instances may also communicate with endpoints not hosted by CSPI700 or outside of CSPI700. Examples of these endpoints include endpoints in a customer on-premise network or data center, or public endpoints accessible over a public network such as the Internet. Communications with endpoints outside of CSPI700 may be performed over a public network (e.g., the Internet) (not shown in FIG. 7) or a private network (not shown in FIG. 7) using a variety of communication protocols.

[0162] The architecture of CSPI700 shown in FIG. 7 is illustrative only and is not intended to be limiting. In alternative embodiments, variations, substitutions, and modifications are possible. For example, in some other embodiments, CSPI700 may have more or fewer systems or components than those shown in FIG. 7, may combine two or more systems, or may have a different configuration or arrangement of systems. The systems, subsystems, and other components shown in FIG. 7 may be implemented in software (e.g., code, instructions, programs) executed by one or more processing units (e.g., processors, cores) of the respective systems, using hardware, or a combination thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device).

[0163] FIG. 9 illustrates a connection between a host machine and an NVD to provide I / O virtualization to support multitenancy functionality according to an embodiment. As shown in FIG. 9, a host machine 902 runs a hypervisor 904 that provides a virtualization environment. The host machine 902 runs two virtual machine instances: VM1 906 that belongs to customer / tenant #1 and VM2 908 that belongs to customer / tenant #2. The host machine 902 includes a physical NIC 910 that is connected to an NVD 912 via a link 914. Each of the compute instances is attached to a VNIC that is executed by the NVD 912. In the embodiment of FIG. 9, VM1 906 is attached to VNIC-VM1 920 and VM2 908 is attached to VNIC-VM2 922.

[0164] 9, NIC 910 includes two logical NICs, logical NIC A 916 and logical NIC B 918. Each virtual machine is attached to and configured to work with its own logical NIC. For example, VM1 906 is attached to logical NIC A 916 and VM2 908 is attached to logical NIC B 918. Although host machine 902 includes only one physical NIC 910 that is shared by multiple tenants, due to the logical NICs, each tenant's virtual machines think they have their own host machine and NIC.

[0165] In one embodiment, each logical NIC is assigned its own VLAN ID. Thus, a particular VLAN ID is assigned to logical NIC A 916 for tenant #1, and a separate VLAN ID is assigned to logical NIC B 918 for tenant #2. When a packet is communicated from VM1 906, a tag assigned to tenant #1 is assigned to the packet by the hypervisor, and the packet is then communicated from the host machine 902 to the NVD 912 over link 914. Similarly, when a packet is communicated from VM2 908, a tag assigned to tenant #2 is assigned to the packet by the hypervisor, and the packet is then communicated from the host machine 902 to the NVD 912 over link 914. Thus, a packet 924 communicated from the host machine 902 to the NVD 912 has an associated tag 926 that identifies the particular tenant and associated VM. For a packet 924 received on the NVD from a host machine 902, a tag 926 associated with the packet is used to determine whether the packet should be processed by VNIC-VM1 920 or VNIC-VM2 922. The packet is then processed by the corresponding VNIC. The configuration shown in Figure 9 allows each tenant's compute instances to think that they own their own host machine and NIC. The setup shown in Figure 9 provides I / O virtualization to support multi-tenancy.

[0166] FIG. 10 illustrates a simplified block diagram of a physical network 1000 according to an embodiment. The embodiment illustrated in FIG. 10 is structured as a Clos network. A Clos network is a specific type of network topology designed to provide connection redundancy while maintaining high bisection bandwidth and maximum resource utilization. A Clos network is a type of non-blocking, multi-stage or multi-tier switching network, where the number of stages or tiers can be 2, 3, 4, 5, etc. The embodiment illustrated in FIG. 10 is a three-tier network with tiers 1, 2, and 3. A TOR switch 1004 represents a tier 0 switch in a Clos network. One or more NVDs are connected to the TOR switch. The tier 0 switch is also referred to as an edge device of the physical network. The tier 0 switch is connected to a tier 1 switch, also referred to as a leaf switch. In the embodiment illustrated in FIG. 10, a set of "n" tier 0 TOR switches are connected to a set of "n" tier 1 switches, together forming a pod. Each tier 0 switch in a pod is interconnected to all tier 1 switches within the pod, but there is no switch connectivity between pods. In one embodiment, two pods are referred to as blocks. Each block is served by or connected to a set of "n" tier 2 switches (sometimes called spine switches). There may be several blocks in the physical network topology. The tier 2 switches are then connected to "n" tier 3 switches (sometimes called super spine switches). Communication of packets through the physical network 1000 is typically performed using one or more layer 3 communication protocols. Typically, all layers of the physical network except the TOR layer are n-way redundant, thus enabling high availability. Policies can be specified for pods and blocks to control the visibility of switches in the physical network to each other to enable scaling of the physical network.

[0167] A feature of Clos networks is that the maximum hop count to reach from one tier 0 switch to another tier 0 switch (or from an NVD connected to a tier 0 switch to another NVD connected to a tier 0 switch) is fixed. For example, in a three-tier Clos network, a maximum of seven hops are required for a packet to reach from one NVD to another NVD, where the source and destination NVDs are connected to the leaf tiers of the Clos network. Similarly, in a four-tier Clos network, a maximum of nine hops are required for a packet to reach from one NVD to another NVD, where the source and destination NVDs are connected to the leaf tiers of the Clos network. Thus, the Clos network architecture maintains consistent latency throughout the network, which is important for communication within and between data centers. Clos topologies scale horizontally and are cost-efficient. The bandwidth / throughput capacity of the network can be easily increased by adding more switches (e.g., more leaf and spine switches) to various tiers and by increasing the number of links between switches in adjacent tiers.

[0168] In one embodiment, each resource in the CSPI is assigned a unique identifier called a Cloud Identifier (CID). This identifier is included as part of the resource's information and can be used to manage the resource, for example, via a console or through an API. An exemplary syntax for a CID is as follows:

[0169] ocid1.<RESOURCE TYPE> . <realm>.[REGION][.FUTURE USE].<UNIQUE ID> Where: ocid1: A string indicating the version of the CID. resource type: The type of resource (for example, instance, volume, VCN, subnet, user, group, etc.). realm: The realm the resource is in. Example values ​​are "c1" for a commercial realm, "c2" for a government cloud realm, or "c3" for a federal cloud realm, etc. Each realm can have its own domain name. region: The region the resource is in. This part can be blank if no region is applicable to the resource. future use: Reserved for future use. unique ID: The unique part of the ID. The format can vary depending on the type of resource or service.

[0170] 11 is a block diagram 1100 illustrating an example pattern of an IaaS architecture according to at least one embodiment. A service operator 1102 may be communicatively coupled to a secure host tenancy 1104, which may include a virtual cloud network (VCN) 1106 and a secure host subnet 1108. In some examples, the service operator 1102 may be a portable handheld device (e.g., iPhone, mobile phone, iPad, computing tablet, personal digital assistant (PDA)) or a wearable device (e.g., Google Glass head mounted display) running software such as Microsoft Windows Mobile and / or various mobile operating systems such as iOS, Windows Phone, Android, BlackBerry 8, Palm OS, etc., and enabled for Internet, email, short message service (SMS), Blackberry, or other communications protocols, and may use one or more client computing devices. Alternatively, the client computing devices may be general purpose personal computers including, by way of example, personal computers and / or laptops running various versions of Microsoft Windows, Apple Macintosh, and / or Linux operating systems. The client computing devices may be workstation computers running any of the various commercially available UNIX or UNIX-like operating systems including, by way of example, but not by way of limitation, various GNU / Linux operating systems such as Google Chrome OS.Alternatively, or in addition, the client computing device may be any other electronic device capable of communicating over a network, such as a thin-client computer, an Internet-enabled gaming system (e.g., a Microsoft® Xbox gaming console with or without a Kinect® gesture input device), and / or a personal messaging device, that has access to the VCN 1106 and / or the Internet.

[0171] The VCN 1106 may include a local peering gateway (LPG) 1110, which may be communicatively coupled to a secure shell (SSH) VCN 1112 via an LPG 1110 included in the SSH VCN 1112. The SSH VCN 1112 may include an SSH subnet 1114, which may be communicatively coupled to a control plane VCN 1116 via an LPG 1110 included in the control plane VCN 1116. The SSH VCN 1112 may also be communicatively coupled to a data plane VCN 1118 via the LPG 1110. The control plane VCN 1116 and the data plane VCN 1118 may be included in a service tenancy 1119, which may be owned and / or operated by the IaaS provider.

[0172] The control plane VCN 1116 can include a control plane demilitarized zone (DMZ) tier 1120 that acts as a perimeter network (e.g., a portion of an enterprise network between the enterprise intranet and an external network). DMZ-based servers can be limited in role and can help keep breaches contained. Additionally, the DMZ tier 1120 can include one or more load balancer (LB) subnets 1122, a control plane app tier 1124 that can include app subnets 1126, a control plane data tier 1128 that can include database (DB) subnets 1130 (e.g., a front-end DB subnet and / or a back-end DB subnet). The LB subnet 1122 included in the control plane DMZ tier 1120 can be communicatively coupled to an app subnet 1126 included in the control plane app tier 1124 and an Internet gateway 1134 that may be included in the control plane VCN 1116, which can be communicatively coupled to a DB subnet 1130 included in the control plane data tier 1128 as well as a service gateway 1136 and a network address translation (NAT) gateway 1138. The control plane VCN 1116 can include the service gateway 1136 and the NAT gateway 1138.

[0173] The control plane VCN 1116 can include a data plane mirrored app tier 1140, which can include an app subnet 1126. The app subnet 1126 included in the data plane mirrored app tier 1140 can include a virtual network interface controller (VNIC) 1142, which can run a compute instance 1144. The compute instance 1144 can be communicatively coupled to the app subnet 1126 of the data plane mirrored app tier 1140 to the app subnet 1126, which can be included in the data plane app tier 1146.

[0174] The data plane VCN 1118 can include a data plane app tier 1146, a data plane DMZ tier 1148, and a data plane data tier 1150. The data plane DMZ tier 1148 can include a LB subnet 1122 that can be communicatively coupled to an app subnet 1126 of the data plane app tier 1146 and an Internet gateway 1134 of the data plane VCN 1118. The app subnet 1126 can be communicatively coupled to a service gateway 1136 of the data plane VCN 1118 and a NAT gateway 1138 of the data plane VCN 1118. The data plane data tier 1150 can also include a DB subnet 1130 that can be communicatively coupled to the app subnet 1126 of the data plane app tier 1146.

[0175] The Internet gateways 1134 of the control plane VCNs 1116 and the data plane VCNs 1118 may be communicatively coupled to a metadata management service 1152, which may be communicatively coupled to the public Internet 1154. The public Internet 1154 may be communicatively coupled to a NAT gateway 1138 of the control plane VCNs 1116 and the data plane VCNs 1118. The service gateways 1136 of the control plane VCNs 1116 and the data plane VCNs 1118 may be communicatively coupled to cloud services 1156.

[0176] In some examples, a service gateway 1136 in the control plane VCN 1116 or the data plane VCN 1118 can make application programming interface (API) calls to cloud services 1156 without going through the public Internet 1154. API calls from the service gateway 1136 to the cloud services 1156 are one-way, i.e., the service gateway 1136 can make an API call to the cloud services 1156 and the cloud services 1156 can send the requested data to the service gateway 1136. However, the cloud services 1156 cannot initiate API calls to the service gateway 1136.

[0177] In some examples, the secure host tenancy 1104 can be directly connected to the service tenancy 1119, which may be otherwise separate. The secure host subnet 1108 can communicate with the SSH subnet 1114 through the LPG 1110, which may enable bidirectional communication through otherwise separate systems. Connecting the secure host subnet 1108 to the SSH subnet 1114 allows the secure host subnet 1108 to access other entities in the service tenancy 1119.

[0178] The control plane VCN 1116 can enable users of the service tenancy 1119 to set up or otherwise provision desired resources. The desired resources provisioned in the control plane VCN 1116 can be deployed or otherwise used in the data plane VCN 1118. In some examples, the control plane VCN 1116 can be separate from the data plane VCN 1118, and the data plane mirror app tier 1140 of the control plane VCN 1116 can communicate with the data plane app tier 1146 of the data plane VCN 1118 via a VNIC 1142, which can be contained within the data plane mirror app tier 1140 and the data plane app tier 1146.

[0179] In some examples, a user or customer of the system can make a request, for example, a create, read, update, or delete (CRUD) operation, through the public Internet 1154, which can communicate the request to the metadata management service 1152. The metadata management service 1152 can communicate the request to the control plane VCN 1116 through the Internet gateway 1134. The request can be received by the LB subnet 1122 contained within the control plane DMZ tier 1120. The LB subnet 1122 can determine that the request is valid, and in response to this determination, the LB subnet 1122 can send the request to the app subnet 1126 contained within the control plane app tier 1124. If the request is validated and requires a call to the public Internet 1154, the call to the public Internet 1154 can be sent to the NAT gateway 1138, which can make the call to the public Internet 1154. Memory that may be desired to be stored by the request can be stored within the DB subnet 1130.

[0180] In some examples, the data plane mirror app tier 1140 can facilitate direct communication between the control plane VCN 1116 and the data plane VCN 1118. For example, it may be desired that a configuration change, update, or other suitable modification be made to the resources contained within the data plane VCN 1118. Through the VNIC 1142, the control plane VCN 1116 can communicate directly with the data plane VCN 1118, thereby performing the configuration change, update, or other suitable modification to the resources contained within the data plane VCN 1118.

[0181] In some embodiments, the control plane VCN 1116 and the data plane VCN 1118 can be included in the service tenancy 1119. In this case, a user or customer of the system may not own or operate either the control plane VCN 1116 or the data plane VCN 1118. Instead, an IaaS provider may own or operate the control plane VCN 1116 and the data plane VCN 1118, both of which may be included in the service tenancy 1119. This embodiment may allow for network isolation that may prevent a user or customer from interfering with the resources of other users or customers. This embodiment may also allow a user or customer of the system to store databases privately without having to rely on the public Internet 1154, which may not have the desired level of threat protection for storage.

[0182] In another embodiment, the LB subnet 1122 contained within the control plane VCN 1116 can be configured to receive signals from the service gateway 1136. In this embodiment, the control plane VCN 1116 and the data plane VCN 1118 can be configured to be called by customers of the IaaS provider without having to call the public Internet 1154. Customers of the IaaS provider may desire this embodiment because databases used by the customers can be stored in a service tenancy 1119 that can be controlled by the IaaS provider and isolated from the public Internet 1154.

[0183] FIG. 12 is a block diagram 1200 illustrating another example pattern of an IaaS architecture, according to at least one embodiment. A service operator 1202 (e.g., service operator 1102 of FIG. 11 ) may be communicatively coupled to a secure host tenancy 1204 (e.g., secure host tenancy 1104 of FIG. 11 ), which may include a virtual cloud network (VCN) 1206 (e.g., VCN 1106 of FIG. 11 ) and a secure host subnet 1208 (e.g., secure host subnet 1108 of FIG. 11 ). VCN 1206 may include a local peering gateway (LPG) 1210 (e.g., LPG 1110 of FIG. 11 ), which may be communicatively coupled to a secure shell (SSH) VCN 1212 (e.g., SSH VCN 1112 of FIG. 11 ) via LPG 1110 included in secure shell (SSH) VCN 1212. SSH VCN 1212 can include an SSH subnet 1214 (e.g., SSH subnet 1114 in FIG. 11 ), which can be communicatively coupled to a control plane VCN 1216 (e.g., control plane VCN 1116 in FIG. 11 ) via an LPG 1210 included in the control plane VCN 1216. The control plane VCN 1216 can be included in a service tenancy 1219 (e.g., service tenancy 1119 in FIG. 11 ), and the data plane VCN 1218 (e.g., data plane VCN 1118 in FIG. 11 ) can be included in a customer tenancy 1221, which can be owned or operated by a user or customer of the system.

[0184] The control plane VCN 1216 may include a control plane DMZ tier 1220 (e.g., the control plane DMZ tier 1120 of FIG. 11 ) that may include a LB subnet 1222 (e.g., the LB subnet 1122 of FIG. 11 ), a control plane app tier 1224 (e.g., the control plane app tier 1124 of FIG. 11 ) that may include an app subnet 1226 (e.g., the app subnet 1126 of FIG. 11 ), and a control plane data tier 1228 (e.g., the control plane data tier 1128 of FIG. 11 ) that may include a database (DB) subnet 1230 (e.g., similar to the DB subnet 1130 of FIG. 11 ). The LB subnet 1222 included in the control plane DMZ tier 1220 can be communicatively coupled to an app subnet 1226 included in the control plane app tier 1224 and an Internet gateway 1234 (e.g., Internet gateway 1134 in FIG. 11 ) that may be included in the control plane VCN 1216, and the app subnet 1226 can be communicatively coupled to a DB subnet 1230 included in the control plane data tier 1228 as well as a service gateway 1236 (e.g., service gateway in FIG. 11 ) and a network address translation (NAT) gateway 1238 (e.g., NAT gateway 1138 in FIG. 11 ). The control plane VCN 1216 can include the service gateway 1236 and the NAT gateway 1238.

[0185] The control plane VCN 1216 can include a data plane mirror app tier 1240 (e.g., data plane mirror app tier 1140 of FIG. 11 ), which can include an app subnet 1226. The app subnet 1226 included in the data plane mirror app tier 1240 can include a virtual network interface controller (VNIC) 1242 (e.g., VNIC 1142) on which a computer instance 1244 (e.g., similar to computer instance 1144 of FIG. 11 ) can run. The computer instance 1244 can facilitate communication between the app subnet 1226 of the data plane mirror app tier 1240 and the app subnet 1226, which can be included in the data plane app tier 1246 (e.g., data plane app tier 1146 of FIG. 11 ), via the VNIC 1242 included in the data plane mirror app tier 1240 and the VNIC 1242 included in the data plane app tier 1246.

[0186] An Internet gateway 1234 contained within the control plane VCN 1216 may be communicatively coupled to a metadata management service 1252 (e.g., metadata management service 1152 of FIG. 11 ), which may be communicatively coupled to a public Internet 1254 (e.g., public Internet 1154 of FIG. 11 ). The public Internet 1254 may be communicatively coupled to a NAT gateway 1238 contained within the control plane VCN 1216. A service gateway 1236 contained within the control plane VCN 1216 may be communicatively coupled to cloud services 1256 (e.g., cloud services 1156 of FIG. 11 ).

[0187] In some examples, the data plane VCN 1218 can be included in the customer tenancy 1221. In this case, the IaaS provider can provide the control plane VCN 1216 for each customer, and the IaaS provider can set up a unique compute instance 1244 for each customer that is contained within the service tenancy 1219. Each compute instance 1244 can enable communication between the control plane VCN 1216 contained within the service tenancy 1219 and the data plane VCN 1218 contained within the customer tenancy 1221. The compute instance 1244 can enable resources provisioned within the control plane VCN 1216 contained within the service tenancy 1219 to be deployed or otherwise used within the data plane VCN 1218 contained within the customer tenancy 1221.

[0188] In another example, an IaaS provider customer may have a database that resides in customer tenancy 1221. In this example, control plane VCN 1216 may include data plane mirror app tier 1240, which may include app subnet 1226. Data plane mirror app tier 1240 may reside in data plane VCN 1218, but data plane mirror app tier 1240 may not reside in data plane VCN 1218. That is, data plane mirror app tier 1240 may have access to customer tenancy 1221, but data plane mirror app tier 1240 may not reside in data plane VCN 1218 or be owned or operated by the IaaS provider customer. Data plane mirror app tier 1240 may be configured to make calls to data plane VCN 1218, but may not be configured to make calls to any entities contained within control plane VCN 1216. A customer may desire to deploy or otherwise use resources in the data plane VCN 1218 that have been provisioned in the control plane VCN 1216, and the data plane mirror app tier 1240 can facilitate the deployment or other use of the customer's desired resources.

[0189] In some examples, an IaaS provider's customer can apply filters to the data plane VCN 1218. In this embodiment, the customer can determine what the data plane VCN 1218 can access, and the customer can restrict access from the data plane VCN 1218 to the public Internet 1254. The IaaS provider may not be able to filter or otherwise control the data plane VCN 1218's access to any external networks or databases. The customer's application of filters and control to the data plane VCN 1218 contained within the customer tenancy 1221 can help isolate the data plane VCN 1218 from other customers and the public Internet 1254.

[0190] In some embodiments, cloud services 1256 can be called by service gateway 1236 to access services that may not be on the public internet 1254, control plane VCN 1216, or data plane VCN 1218. The connection between cloud services 1256 and control plane VCN 1216 or data plane VCN 1218 may not be live or continuous. Cloud services 1256 may be on different networks owned or operated by the IaaS provider. Cloud services 1256 can be configured to receive calls from service gateway 1236 and not receive calls from the public internet 1254. Some cloud services 1256 can be isolated from other cloud services 1256, and control plane VCN 1216 can be isolated from cloud services 1256 that may not be in the same region as control plane VCN 1216. For example, control plane VCN 1216 may be located in “Region 1” and cloud service “Deployment 11” may be located in Region 1 and “Region 2.” If a call to deployment 11 is made by a service gateway 1236 contained within a control plane VCN 1216 located in region 1, the call may be sent to deployment 11 in region 1. In this example, control plane VCN 1216 or deployment 11 in region 1 may not be communicatively coupled to or otherwise in communication with deployment 11 in region 2.

[0191] 13 is a block diagram 1300 illustrating another example pattern of an IaaS architecture, according to at least one embodiment. A service operator 1302 (e.g., service operator 1102 of FIG. 11 ) may be communicatively coupled to a secure host tenancy 1304 (e.g., secure host tenancy 1104 of FIG. 11 ), which may include a virtual cloud network (VCN) 1306 (e.g., VCN 1106 of FIG. 11 ) and a secure host subnet 1308 (e.g., secure host subnet 1108 of FIG. 11 ). The VCN 1306 may include an LPG 1310 (e.g., LPG 1110 of FIG. 11 ), which may be communicatively coupled to an SSH VCN 1312 (e.g., SSH VCN 1112 of FIG. 11 ) via the LPG 1310 included in the SSH VCN 1312. SSH VCN 1312 can include an SSH subnet 1314 (e.g., SSH subnet 1114 in FIG. 11 ), which can be communicatively coupled to a control plane VCN 1316 (e.g., control plane VCN 1116 in FIG. 11 ) via an LPG 1310 included in the control plane VCN 1316, and to a data plane VCN 1318 (e.g., data plane VCN 1118 in FIG. 11 ) via an LPG 1310 included in the data plane VCN 1318. The control plane VCN 1316 and the data plane VCN 1318 can be included in a service tenancy 1319 (e.g., service tenancy 1119 in FIG. 11 ).

[0192] The control plane VCN 1316 may include a control plane DMZ tier 1320 (e.g., the control plane DMZ tier 1120 of FIG. 11 ) that may include a load balancer (LB) subnet 1322 (e.g., the LB subnet 1122 of FIG. 11 ), a control plane app tier 1324 (e.g., the control plane app tier 1124 of FIG. 11 ) that may include an app subnet 1326 (e.g., similar to the app subnet 1126 of FIG. 11 ), and a control plane data tier 1328 (e.g., the control plane data tier 1128 of FIG. 11 ) that may include a DB subnet 1330. The LB subnet 1322 included in the control plane DMZ tier 1320 can be communicatively coupled to an app subnet 1326 included in the control plane app tier 1324 and an Internet gateway 1334 (e.g., Internet gateway 1134 in FIG. 11 ) that may be included in the control plane VCN 1316, and the app subnet 1326 can be communicatively coupled to a DB subnet 1330 included in the control plane data tier 1328 as well as a service gateway 1336 (e.g., service gateway in FIG. 11 ) and a network address translation (NAT) gateway 1338 (e.g., NAT gateway 1138 in FIG. 11 ). The control plane VCN 1316 can include the service gateway 1336 and the NAT gateway 1338.

[0193] The data plane VCN 1318 can include a data plane app tier 1346 (e.g., data plane app tier 1146 of FIG. 11 ), a data plane DMZ tier 1348 (e.g., data plane DMZ tier 1148 of FIG. 11 ), and a data plane data tier 1350 (e.g., data plane data tier 1150 of FIG. 11 ). The data plane DMZ tier 1348 can include a trusted app subnet 1360 and an untrusted app subnet 1362 of the data plane app tier 1346 and a LB subnet 1322 that can be communicatively coupled to an Internet gateway 1334 contained within the data plane VCN 1318. The trusted app subnet 1360 can be communicatively coupled to a service gateway 1336 contained within the data plane VCN 1318, a NAT gateway 1338 contained within the data plane VCN 1318, and a DB subnet 1330 contained within the data plane data tier 1350. The untrusted app subnet 1362 may be communicatively coupled to a service gateway 1336 contained within the data plane VCN 1318 and a DB subnet 1330 contained within the data plane data hierarchy 1350. The data plane data hierarchy 1350 may include a DB subnet 1330 that may be communicatively coupled to a service gateway 1336 contained within the data plane VCN 1318.

[0194] The untrusted app subnet 1362 may include one or more VNICs 1364(1)-(N), which may be communicatively coupled to tenant virtual machines (VMs) 1366(1)-(N). Each tenant VM 1366(1)-(N) may be communicatively coupled to a respective app subnet 1367(1)-(N), which may be contained within a respective container egress VCN 1368(1)-(N), which may be contained within a respective customer tenancy 1370(1)-(N). Each secondary VNIC 1372(1)-(N) may facilitate communication between the untrusted app subnet 1362 contained within the data plane VCN 1318 and the app subnet contained within the container egress VCN 1368(1)-(N). Each container egress VCN 1368(1)-(N) may include a NAT gateway 1338, which may be communicatively coupled to the public Internet 1354 (e.g., public Internet 1154 of FIG. 11 ).

[0195] The Internet gateway 1334 contained within the control plane VCN 1316 and the Internet gateway 1334 contained within the data plane VCN 1318 may be communicatively coupled to a metadata management service 1352 (e.g., metadata management service 1152 of FIG. 11 ), which may be communicatively coupled to the public Internet 1354. The public Internet 1354 may be communicatively coupled to a NAT gateway 1338 contained within the control plane VCN 1316 and the NAT gateway 1338 contained within the data plane VCN 1318. The service gateway 1336 contained within the control plane VCN 1316 and the service gateway 1336 contained within the data plane VCN 1318 may be communicatively coupled to cloud services 1356.

[0196] In some embodiments, data plane VCN 1318 can be integrated with customer tenancies 1370. This integration can be useful or desirable for an IaaS provider's customers in some cases, such as those cases where support may be desired when executing code. A customer may provide code for execution that may be disruptive, may communicate with other customer resources, or may otherwise cause undesirable effects. In response, the IaaS provider can determine whether or not to execute the code provided to the IaaS provider by the customer.

[0197] In some examples, a customer of an IaaS provider may grant temporary network access to the IaaS provider to request a function associated with data plane tier app 1346. Code to perform the function may run within VMs 1366(1)-(N), and the code may not be configured to run anywhere else on data plane VCN 1318. Each VM 1366(1)-(N) may be connected to one customer tenancy 1370. Each container 1371(1)-(N) contained within VM 1366(1)-(N) may be configured to run code. In this case, there may be double isolation (e.g., containers 1371(1)-(N) executing code, where containers 1371(1)-(N) may be contained within VMs 1366(1)-(N) that are contained within at least untrusted app subnet 1362), which may help prevent incorrect or otherwise undesirable code from damaging the IaaS provider's network or from damaging a different customer's network. Containers 1371(1)-(N) may be communicatively coupled to customer tenancy 1370 and configured to send or receive data from customer tenancy 1370. Containers 1371(1)-(N) may not be configured to send or receive data from any other entity in data plane VCN 1318. Once code execution is complete, the IaaS provider may stop or otherwise destroy containers 1371(1)-(N).

[0198] In some embodiments, trusted app subnet 1360 may execute code that may be owned or operated by the IaaS provider. In this embodiment, trusted app subnet 1360 may be communicatively coupled to DB subnet 1330 and may be configured to perform CRUD operations on DB subnet 1330. Untrusted app subnet 1362 may be communicatively coupled to DB subnet 1330, but in this embodiment, untrusted app subnet 1362 may be configured to perform read operations on DB subnet 1330. Containers 1371(1)-(N) that may be contained within each customer's VMs 1366(1)-(N) and may execute code from the customer may not be communicatively coupled to DB subnet 1330.

[0199] In other embodiments, the control plane VCN 1316 and the data plane VCN 1318 may not be directly communicatively coupled. In this embodiment, there may not be direct communication between the control plane VCN 1316 and the data plane VCN 1318. However, communication may occur indirectly through at least one method. An LPG 1310 may be established by an IaaS provider that may facilitate communication between the control plane VCN 1316 and the data plane VCN 1318. In another example, the control plane VCN 1316 or the data plane VCN 1318 may make a call to a cloud service 1356 via a service gateway 1336. For example, a call from the control plane VCN 1316 to the cloud service 1356 may include a request for a service that may communicate with the data plane VCN 1318.

[0200] FIG. 14 is a block diagram 1400 illustrating another example pattern of an IaaS architecture, according to at least one embodiment. A service operator 1402 (e.g., service operator 1102 of FIG. 11 ) may be communicatively coupled to a secure host tenancy 1404 (e.g., secure host tenancy 1104 of FIG. 11 ), which may include a virtual cloud network (VCN) 1406 (e.g., VCN 1106 of FIG. 11 ) and a secure host subnet 1408 (e.g., secure host subnet 1108 of FIG. 11 ). The VCN 1406 may include an LPG 1410 (e.g., LPG 1110 of FIG. 11 ), which may be communicatively coupled to an SSH VCN 1412 (e.g., SSH VCN 1112 of FIG. 11 ) via the LPG 1410 included in the SSH VCN 1412. SSH VCN 1412 can include an SSH subnet 1414 (e.g., SSH subnet 1114 in FIG. 11 ), which can be communicatively coupled to a control plane VCN 1416 (e.g., control plane VCN 1116 in FIG. 11 ) via an LPG 1410 included in control plane VCN 1416, and to a data plane VCN 1418 (e.g., data plane VCN 1118 in FIG. 11 ) via an LPG 1410 included in data plane VCN 1418. Control plane VCN 1416 and data plane VCN 1418 can be included in service tenancy 1419 (e.g., service tenancy 1119 in FIG. 11 ).

[0201] The control plane VCN 1416 may include a control plane DMZ tier 1420 (e.g., the control plane DMZ tier 1120 of FIG. 11) that may include a LB subnet 1422 (e.g., the LB subnet 1122 of FIG. 11), a control plane app tier 1424 (e.g., the control plane app tier 1124 of FIG. 11) that may include an app subnet 1426 (e.g., the app subnet 1126 of FIG. 11), and a control plane data tier 1428 (e.g., the control plane data tier 1128 of FIG. 11) that may include a DB subnet 1430 (e.g., the DB subnet 1330 of FIG. 13). The LB subnet 1422 included in the control plane DMZ tier 1420 can be communicatively coupled to an app subnet 1426 included in the control plane app tier 1424 and an Internet gateway 1434 (e.g., Internet gateway 1134 in FIG. 11 ) that may be included in the control plane VCN 1416, and the app subnet 1426 can be communicatively coupled to a DB subnet 1430 included in the control plane data tier 1428 as well as a service gateway 1436 (e.g., service gateway in FIG. 11 ) and a network address translation (NAT) gateway 1438 (e.g., NAT gateway 1138 in FIG. 11 ). The control plane VCN 1416 can include the service gateway 1436 and the NAT gateway 1438.

[0202] The data plane VCN 1418 can include a data plane app tier 1446 (e.g., data plane app tier 1146 of FIG. 11 ), a data plane DMZ tier 1448 (e.g., data plane DMZ tier 1148 of FIG. 11 ), and a data plane data tier 1450 (e.g., data plane data tier 1150 of FIG. 11 ). The data plane DMZ tier 1448 can include a trusted app subnet 1460 (e.g., trusted app subnet 1360 of FIG. 13 ) and an untrusted app subnet 1462 (e.g., untrusted app subnet 1362 of FIG. 13 ) of the data plane app tier 1446, as well as a LB subnet 1422 that can be communicatively coupled to an Internet gateway 1434 contained within the data plane VCN 1418. The trusted app subnet 1460 may be communicatively coupled to a service gateway 1436 contained within the data plane VCN 1418, a NAT gateway 1438 contained within the data plane VCN 1418, and a DB subnet 1430 contained within the data plane data hierarchy 1450. The untrusted app subnet 1462 may be communicatively coupled to a service gateway 1436 contained within the data plane VCN 1418 and a DB subnet 1430 contained within the data plane data hierarchy 1450. The data plane data hierarchy 1450 may include a DB subnet 1430 that may be communicatively coupled to a service gateway 1436 contained within the data plane VCN 1418.

[0203] The untrusted app subnet 1462 may include primary VNICs 1464(1)-(N) that may be communicatively coupled to tenant virtual machines (VMs) 1466(1)-(N) that reside in the untrusted app subnet 1462. Each tenant VM 1466(1)-(N) may execute code in a respective container 1467(1)-(N) and may be communicatively coupled to an app subnet 1426 that may be contained in a data plane app tier 1446 that may be contained in a container egress VCN 1468. Each secondary VNIC 1472(1)-(N) may facilitate communication between the untrusted app subnet 1462 that is contained in the data plane VCN 1418 and the app subnet that is contained in the container egress VCN 1468. The container egress VCN may include a NAT gateway 1438 that may be communicatively coupled to the public Internet 1454 (e.g., public Internet 1154 of FIG. 11 ).

[0204] The Internet gateway 1434 contained within the control plane VCN 1416 and the Internet gateway 1434 contained within the data plane VCN 1418 may be communicatively coupled to a metadata management service 1452 (e.g., metadata management service 1152 of FIG. 11 ), which may be communicatively coupled to the public Internet 1454. The public Internet 1454 may be communicatively coupled to a NAT gateway 1438 contained within the control plane VCN 1416 and the NAT gateway 1438 contained within the data plane VCN 1418. The service gateway 1436 contained within the control plane VCN 1416 and the service gateway 1436 contained within the data plane VCN 1418 may be communicatively coupled to cloud services 1456.

[0205] In some examples, the pattern illustrated by the architecture of block diagram 1400 of FIG. 14 may be considered an exception to the pattern illustrated by the architecture of block diagram 1300 of FIG. 13 and may be desirable for an IaaS provider's customer when the IaaS provider cannot communicate directly with the customer (e.g., in an isolated region). Each container 1467(1)-(N) contained within each customer's VM 1466(1)-(N) can be accessed in real time by the customer. The containers 1467(1)-(N) can be configured to make calls to each secondary VNIC 1472(1)-(N) contained within the app subnet 1426 of the data plane app tier 1446, which may be contained within a container egress VCN 1468. The secondary VNIC 1472(1)-(N) can send the call to a NAT gateway 1438, which can send the call to the public Internet 1454. In this example, containers 1467(1)-(N) that may be accessed in real time by a customer may be isolated from control plane VCN 1416 and may be isolated from other entities contained within data plane VCN 1418. Containers 1467(1)-(N) may also be isolated from resources of other customers.

[0206] In another example, a customer can call cloud service 1456 using container 1467(1)-(N). In this example, the customer can execute code within container 1467(1)-(N) that requests a service from cloud service 1456. Container 1467(1)-(N) can send the request to secondary VNIC 1472(1)-(N), which can send the request to a NAT gateway, which can send the request to public Internet 1454. Public Internet 1454 can send the request to LB subnet 1422, which is contained within control plane VCN 1416, via Internet gateway 1434. In response to determining that the request is valid, LB subnet 1426 can send the request to app subnet 1426, which can send the request to cloud service 1456 via service gateway 1436.

[0207] It should be understood that the IaaS architectures 1100, 1200, 1300, 1400 depicted in the drawings may have components other than those depicted. Additionally, the embodiments depicted in the drawings are only some examples of cloud infrastructure systems that may incorporate embodiments of the present disclosure. In some other embodiments, the IaaS system may have more or fewer components than depicted, may combine two or more components, or may have a different configuration or arrangement of components.

[0208] In certain embodiments, the IaaS system described herein may include a suite of application, middleware, and database service offerings that are delivered to customers on a self-service, subscription-based, elastically scalable, reliable, highly available, and secure basis. One example of such an IaaS is Oracle Infrastructure (OCI) offered by the present assignee.

[0209] 15 illustrates an exemplary computer system 1500 on which various embodiments may be implemented. The system 1500 may be used to implement any of the computer systems described above. As shown in the drawing, the computer system 1500 includes a processing unit 1504 that communicates with a number of peripheral subsystems via a bus subsystem 1502. These peripheral subsystems may include a processing acceleration unit 1506, an I / O subsystem 1508, a storage subsystem 1518, and a communication subsystem 1524. The storage subsystem 1518 includes a tangible computer readable storage medium 1522 and a system memory 1510.

[0210] Bus subsystem 1502 provides a mechanism for allowing the various components and subsystems of computer system 1500 to communicate with each other as intended. Although bus subsystem 1502 is shown diagrammatically as a single bus, alternative embodiments of the bus subsystem may utilize multiple buses. Bus subsystem 1502 may be any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. For example, such architectures may include an Industry Standard Architecture (ISA) bus, a MicroChannel Architecture (MCA) bus, an Enhanced ISA (EISA) bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus, which may be implemented as a Mezzanine bus manufactured in accordance with the IEEE P1386.1 standard.

[0211] The processing unit 1504, which may be implemented as one or more integrated circuits (e.g., conventional microprocessors or microcontrollers), controls the operation of the computer system 1500. One or more processors may be included in the processing unit 1504. These processors may include single-core or multi-core processors. In some embodiments, the processing unit 1504 may be implemented as one or more independent processing units 1532 and / or 1534 with single or multi-core processors included in each processing unit. In other embodiments, the processing unit 1504 may also be implemented as a quad-core processing unit formed by integrating two dual-core processors on a single chip.

[0212] In various embodiments, the processing unit 1504 may execute various programs in response to program code and may maintain multiple simultaneously executing programs or processes. At any given time, some or all of the program code being executed may reside within the processor 1504 and / or the storage subsystem 1518. Through appropriate programming, the processor 1504 may provide various functions as discussed above. The computer system 1500 may additionally include a processing acceleration unit 1506, which may include a digital signal processor (DSP), special purpose processor, or the like.

[0213] The I / O subsystem 1508 can include user interface input devices and user interface output devices. User interface input devices can include pointing devices such as a keyboard, a mouse or trackball, a touchpad or a touch screen integrated into a display, scroll wheels, click wheels, dials, buttons, switches, keypads, acoustic input devices with voice command recognition systems, microphones, and other types of input devices. User interface input devices can include motion sensing and / or gesture recognition devices such as a Microsoft Kinect® motion sensor that allows a user to control and interact with an input device such as a Microsoft Xbox® 360 game controller through a natural user interface using gestures and voice instructions. User interface input devices can also include eye gesture recognition devices such as a Google Glass® blink detector that detects eye activity from a user (e.g., "blinking" while taking a picture and / or making a menu selection) and translates the eye gesture as input to an input device (e.g., Google Glass®). Additionally, the user interface input devices may include a voice recognition sensing device that allows a user to interact with a voice recognition system (eg, the Siri® navigator) through voice commands.

[0214] User interface input devices may also include, but are not limited to, three-dimensional (3D) mice, joysticks or pointing sticks, game pads and graphic tablets, as well as audio / visual devices such as speakers, digital cameras, digital camcorders, portable media players, webcams, image scanners, fingerprint scanners, barcode readers 3D scanners, 3D printers, laser range finders, and eye-tracking devices. Additionally, user interface input devices may include medical imaging input devices, such as, for example, computed tomography, magnetic resonance imaging, position emission tomography, medical ultrasound devices, and the like. User interface input devices may also include audio input devices, such as, for example, MIDI keyboards, digital musical instruments, and the like.

[0215] User interface output devices may include non-visual displays such as a display subsystem, indicator lights, or audio output devices. The display subsystem may be a flat panel device such as one using a cathode ray tube (CRT), liquid crystal display (LCD) or plasma display, a projection device, a touch screen, etc. In general, use of the term "output device" is intended to include all possible types of devices and mechanisms for outputting information from computing device 1500 to a user or to another computer. For example, user interface output devices may include a variety of display devices that visually convey text, graphics, and audio / video information, such as, but not limited to, monitors, printers, speakers, headphones, automobile navigation systems, plotters, audio output devices, and modems.

[0216] Computer system 1500 may include a storage subsystem 1518 that includes software elements, currently shown as residing in system memory 1510. System memory 1510 may store program instructions that are loadable and executable on processing unit 1504, as well as data generated during the execution of these programs.

[0217] Depending on the configuration and type of computer system 1500, system memory 1510 may be volatile (such as random access memory (RAM)) and / or non-volatile (such as read only memory (ROM), flash memory, etc.). RAM typically contains data and / or program modules that are immediately accessible to and / or currently being operated and executed by the processing unit 1504. In some embodiments, system memory 1510 may include a number of different types of memory, such as static random access memory (SRAM) or dynamic random access memory (DRAM). In some embodiments, a basic input / output system (BIOS), which contains the basic routines that help transfer information between elements within computer system 1500, such as during start-up, may typically be stored in ROM. By way of example and not limitation, system memory 1510 also illustrates application programs 1512, program data 1514, and operating system 1516, which may include client applications, web browsers, mid-tier applications, relational database management systems (RDBMS), and the like. By way of example, operating system 1516 may include various versions of Microsoft Windows®, Apple Macintosh®, and / or various commercially available UNIX® or UNIX-like operating systems (such as, but not limited to, various GNU / Linux operating systems, Google Chrome® OS), and / or mobile operating systems such as iOS, Windows® Phone, Android® OS, BlackBerry® 15 OS, and Palm® OS operating systems.

[0218] The storage subsystem 1518 may also provide a tangible computer readable storage medium for storing the basic programming and data structures that provide the functionality of some embodiments. Software (programs, code modules, instructions) that, when executed by the processor, provide the functionality described above may be stored in the storage subsystem 1518. These software modules or instructions may be executed by the processing unit 1504. The storage subsystem 1518 may also provide a repository for storing data used in accordance with the present disclosure.

[0219] Storage subsystem 1500 may also include a computer readable storage medium reader 1520 that may be further connected to a computer readable storage medium 1522. Along with, and optionally in combination with, the system memory 1510, computer readable storage medium 1522 may collectively represent remote, local, fixed, and / or removable storage devices+media for containing, storing, transmitting, and retrieving computer readable information on a temporary and / or more persistent basis.

[0220] The computer readable storage medium 1522 containing the code or portions of code may also include any suitable medium known or used in the art, including storage media and communication media, such as, but not limited to, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing and / or transmitting information. This may include tangible computer readable storage media, such as RAM, ROM, Electrically Erasable Programmable ROM (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other tangible computer readable media. This may also include non-tangible computer readable media, such as a data signal, data transmission, or any other medium that may be used to transmit the desired information and that can be accessed by the computing system 1500.

[0221] By way of example, the computer readable storage medium 1522 may include hard disk drives that read from or write to non-removable non-volatile magnetic media, magnetic disk drives that read from or write to removable non-volatile magnetic disks, and optical disk drives that read from or write to removable non-volatile optical disks, such as CD ROMs, DVDs, and Blu-ray disks or other optical media. The computer readable storage medium 1522 may include, without limitation, Zip drives, flash memory cards, Universal Serial Bus (USB) flash devices, Secure Digital (SD) cards, DVD disks, digital video tapes, and the like. The computer readable storage medium 1522 may also include solid state drives (SSDs) based on non-volatile memory, such as flash memory-based SSDs, enterprise flash drives, solid state ROMs, and the like, SSDs based on volatile memory, such as solid state RAM, dynamic RAM, static RAM, and the like, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, and hybrid SSDs that use a combination of DRAM and flash memory-based SSDs. The disk drives and their associated computer-readable media may provide non-volatile storage of computer readable instructions, data structures, program modules and other data for the computer system 1500.

[0222] The communications subsystem 1524 provides an interface to other computer systems and networks. The communications subsystem 1524 serves as an interface for receiving data from other systems and transmitting data from the computer system 1500 to other systems. For example, the communications subsystem 1524 can enable the computer system 1500 to connect to one or more devices via the Internet. In some embodiments, the communications subsystem 1524 can include radio frequency (RF) transceiver components for accessing wireless voice and / or data networks (e.g., using cellular technology, 3G, 4G or EDGE (Enhanced Data Rates for Global Evolution), advanced data network technologies such as WiFi (IEEE 802.11 family of standards, or other mobile communications technologies, or any combination thereof), global positioning system (GPS) receiver components, and / or other components. In some embodiments, the communications subsystem 1524 can provide a wired network connection (e.g., Ethernet) in addition to or instead of a wireless interface.

[0223] In some embodiments, the communications subsystem 1524 may also receive incoming communications in the form of structured and / or unstructured data feeds 1526, event streams 1528, event updates 1530, etc. on behalf of one or more users who may use the computer system 1500.

[0224] As an example, the communications subsystem 1524 may be configured to receive data feeds 1526 in real time from users of social networks and / or other communications services, such as web feeds such as Twitter® feeds, Facebook® updates, Rich Site Summary (RSS) feeds, and / or real-time updates from one or more third party sources.

[0225] Additionally, the communications subsystem 1524 may also be configured to receive data in the form of continuous data streams, which may include event streams 1528 of real-time events and / or event updates 1530, which may be continuous or unlimited in nature with no apparent end. Examples of applications that generate continuous data may include, for example, sensor data applications, financial tickers, network performance measurement tools (e.g., network monitoring and traffic management applications), clickstream analysis tools, automobile traffic monitoring, etc.

[0226] The communications subsystem 1524 may also be configured to output structured and / or unstructured data feeds 1526, event streams 1528, event updates 1530, etc. to one or more databases that may be in communication with one or more streaming data source computers coupled to the computer system 1500.

[0227] The computer system 1500 can be one of a variety of types, including a handheld portable device (e.g., an iPhone® mobile phone, an iPad® computing tablet, a PDA), a wearable device (e.g., a Google Glass® head mounted display), a PC, a workstation, a mainframe, a kiosk, a server rack, or any other data processing system.

[0228] Due to the ever-changing nature of computers and networks, the description of the computer device 1500 shown in the drawings is intended as a specific example only. Many other configurations are possible, having more or fewer components than the system shown in the drawings. For example, customized hardware may also be used, and / or certain elements may be implemented in hardware, firmware, software (including applets), or a combination. Furthermore, connections to other computing devices, such as network input / output devices, may be utilized. Based on the present disclosure and the teachings provided herein, one skilled in the art will appreciate other ways and / or methods for implementing various embodiments.

[0229] The embodiments may be implemented by using a computer program product comprising computer program instructions which, when executed by a processor, cause the processor to perform any of the methods described in the present disclosure.

[0230] Although specific embodiments have been described, various modifications, variations, alternative configurations, and equivalents are encompassed within the scope of the disclosure. The embodiments are not limited to operation in one particular data processing environment, but can freely operate in multiple data processing environments. Additionally, while the embodiments are described using a particular sequence of transactions and steps, it will be apparent to one skilled in the art that the scope of the disclosure is not limited to the described sequence of transactions and steps. Various features and aspects of the embodiments described above may be used individually or jointly.

[0231] Furthermore, while the embodiments are described using a particular combination of hardware and software, it should be recognized that other combinations of hardware and software are within the scope of the present disclosure. The embodiments may be implemented using only in hardware, only in software, or a combination thereof. The various processes described herein may be implemented on the same processor, or on multiple different processors in any combination. Thus, where a component or module is described as being configured to perform a particular operation, such configuration may be achieved, for example, by designing an electronic circuit to perform the operation, by programming a programmable electronic circuit (such as a microprocessor) to perform the operation, or by any combination thereof. Processes may communicate using a variety of techniques, including, but not limited to, conventional techniques for inter-process communication, and different pairs of processes may use different techniques, or the same pair of processes may use different techniques at different times.

[0232] Accordingly, the specification and drawings are to be considered in an illustrative and not a restrictive sense. It will be apparent, however, that additions, subtractions, deletions, and other modifications and changes may be made thereto without departing from the broader spirit and scope as set forth in the appended claims. Thus, while certain disclosed embodiments have been described, these are not intended to be limiting. Various modifications and equivalents are within the scope of the appended claims.

[0233] Use of the terms "a" and "an" as well as "the" and similar referents in the context of describing embodiments of the present disclosure (particularly in the context of the claims that follow) should be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" should be construed as open-ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. The term "connected" should be construed as being partially or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of individually referring to each separate value falling within the range, unless otherwise indicated herein and incorporated herein as if each separate value were individually set forth herein. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. Any examples or exemplary language provided herein (e.g., "such as") is intended only to facilitate a better understanding of the embodiments and does not impose limitations on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.

[0234] Disjunctive language, such as the phrase "at least one of X, Y, or Z," is intended to be understood within the context as it is commonly used to indicate that an item, term, etc., can be either X, Y, or Z, or any combination thereof (e.g., X, Y, and / or Z), unless specifically stated otherwise. Thus, such disjunctive language is not intended to, and should not, generally imply that an embodiment requires that at least one of X, at least one of Y, or at least one of Z, respectively, be present.

[0235] Preferred embodiments of the present disclosure, including the best mode known for carrying out the present disclosure, are described herein. Modifications of these preferred embodiments may become apparent to those skilled in the art upon reading the above description. Those skilled in the art should be able to utilize such modifications as appropriate, and the present disclosure may be practiced otherwise than as specifically described herein. Accordingly, the present disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, unless otherwise indicated herein, any combination of the above-described elements in all possible variations is encompassed by the present disclosure.

[0236] All references cited in this specification, including publications, patent applications, and patents, are incorporated by reference herein to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.

[0237] In the above specification, aspects of the disclosure are described with reference to specific embodiments thereof, but those skilled in the art will recognize that the disclosure is not limited thereto. Various features and aspects of the above-described disclosure may be used individually or jointly. Moreover, the embodiments may be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. Thus, the specification and drawings should be considered as illustrative and not restrictive.< / realm>

Claims

1. A method, including providing a secure network connection service for enabling a secure private network connection between an on-premises network associated with a customer of the cloud service provider and a virtual cloud network (VCN) hosted by the cloud service provider for the customer, wherein the secure network connection system comprises a virtual overlay network including a set of one or more computing nodes, and the method further comprises the secure network connection system registering an external resource existing within the on-premises network as an external endpoint within the virtual cloud network, the external endpoint being identified by an Internet Protocol (IP) address within the virtual cloud network, and the method further comprises a first computing node of the set of one or more computing nodes within the secure network connection system creating an external resource representation of the external endpoint within the virtual cloud network, creating the external resource representation comprising the first computing node creating a virtual network interface card (VNIC), and the first computing node assigning the Internet Protocol (IP) address associated with the external endpoint to the virtual network interface card (VNIC), and the method further comprises the first computing node transmitting configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation to an agent configured within the on-premises network associated with the customer, and A second computing node of the set of one or more computing nodes within the secure network connection system receives a request to query information associated with resources existing within the virtual cloud network (VCN) associated with the customer, the query being sent by the external resource existing within the on-premises network, the external resource being provisioned with a logical interface, and the method further comprises the second computing node establishing a connection between the logical interface provisioned to the external resource within the on-premises network and a virtual network interface card (VNIC) created for the external resource representation within the virtual cloud network the second computing node sending the request to the resources existing within the virtual cloud network via the established connection the second computing node obtaining a result corresponding to the request via the established connection. A method comprising **Claim 2** The agent within the on-premises network is configured to establish a secure virtual private network (VPN) connection between the external resource existing within the on-premises network and the set of one or more computing nodes comprising the secure network connection system. The method according to claim 1 **Claim 3** The agent is configured to provision the logical interface of the external resource existing within the on-premises network, at least in part based on the configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation. The method according to claim 1 or claim 2 **Claim 4** Provisioning the logical interface of the external resource includes the agent assigning the virtual Internet Protocol (IP) address of the virtual network interface card (VNIC) of the external resource representation to the logical interface, according to the method of claim 3.

5. The configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation includes the virtual Internet Protocol (IP) address of the virtual network interface card (VNIC), the fully qualified domain name associated with the computing instance associated with the virtual network interface card (VNIC), and the cloud identifier of the virtual cloud network associated with the customer, according to the method of claim 3.

6. Establishing the connection between the logical interface provisioned to the external resource existing in the on-premises network by the second computing node and the virtual network interface card created for the external resource representation in the virtual cloud network includes establishing the connection via the agent existing in the on-premises network, according to the method of claim 1 or 2.

7. The second computing node sending the request to the resource existing in the virtual cloud network via the established connection is the second computing node converting the physical IP address associated with the external resource to the virtual IP address associated with the virtual network interface card of the external resource representation in the virtual cloud network associated with the customer, and The method according to claim 1 or 2, wherein a second computing node transmits the request to the virtual IP address associated with the virtual network interface card.

8. The method according to claim 1 or 2, further comprising enabling the secure network connection system to create an external site representation of the on-premises network associated with the customer, wherein the external site representation is a logical representation of the on-premises network and is identified by an external site identifier and a customer identifier.

9. The method according to claim 8, wherein the external resource is registered within the external site representation.

10. The method according to claim 9, further comprising establishing a connection between the logical interface provisioned to the external resource existing within the external site representation by the second computing node and the virtual network interface card created for the external resource representation within the virtual cloud network.

11. The method according to claim 1 or 2, wherein the external resource is a database, an application, or a computing instance existing within the on-premises network.

12. A secure network connection system for enabling a secure private network connection between an on-premises network associated with a customer of a cloud service provider and a virtual cloud network (VCN) hosted by the cloud service provider for the customer, implemented in the cloud service provider, the secure network connection system comprising a virtual overlay network including a set of one or more computing nodes, wherein the computing nodes in the set of computing nodes are memory, One or more processors configured to perform a process, wherein the process comprises registering, by the secure network connection system, an external resource existing within the on-premises network as an external endpoint within the virtual cloud network, wherein the external endpoint is identified by an Internet Protocol (IP) address within the virtual cloud network, and the process further comprises creating, by a first computing node of the set of one or more computing nodes within the secure network connection system, an external resource representation of the external endpoint within the virtual cloud network, wherein creating the external resource representation comprises creating, by the first computing node of the set of one or more computing nodes within the secure network connection system, a virtual network interface card (VNIC), and assigning, by the first computing node of the set of one or more computing nodes within the secure network connection system, the Internet Protocol (IP) address associated with the external endpoint to the virtual network interface card (VNIC), and the process further comprises transmitting, by the first computing node within the secure network connection system, configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation to an agent configured within the on-premises network associated with the customer, and The second computing node of the set of one or more computing nodes within the secure network connection system receives a request for querying information associated with resources existing within the virtual cloud network (VCN) associated with the customer, where the query is sent by the external resource existing within the on-premises network, and the external resource is provisioned with a logical interface, and the process further The second computing node within the secure network connection system establishes a connection between the logical interface provisioned to the external resource within the on-premises network and the virtual network interface card (VNIC) created for the external resource representation within the virtual cloud network. The second computing node within the secure network connection system sends the request to the resources existing within the virtual cloud network via the established connection. The second computing node within the secure network connection system obtains a result corresponding to the request via the established connection, the secure network connection system comprising. Claim 13 The agent within the on-premises network is configured to establish a secure virtual private network (VPN) connection between the external resource existing within the on-premises network and the set of one or more computing nodes comprising the secure network connection system, the system according to claim 12. Claim 14 The system according to claim 12 or claim 13, wherein the agent is configured to provision a logical interface of the external resource existing in the on-premises network based at least in part on the configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation.

15. Provisioning the logical interface of the external resource includes the agent assigning the virtual Internet Protocol (IP) address of the virtual network interface card (VNIC) of the external resource representation to the logical interface, according to the system of claim 14.

16. The configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation includes the virtual Internet Protocol (IP) address of the virtual network interface card (VNIC), the fully qualified domain name associated with the computing instance associated with the virtual network interface card (VNIC), and the cloud identifier of the virtual cloud network associated with the customer, according to the system of claim 12 or 13.

17. A computer program including program code, the program code being executable by one or more processing devices to perform a plurality of operations, the plurality of operations including registering an external resource existing in the on-premises network as an external endpoint in a virtual cloud network, the external endpoint being identified by an Internet Protocol (IP) address in the virtual cloud network, and the plurality of operations further including creating an external resource representation of the external endpoint in the virtual cloud network, creating the external resource representation including Creating a virtual network interface card (VNIC), and assigning the Internet Protocol (IP) address associated with the external endpoint to the virtual network interface card (VNIC), and the plurality of operations further include transmitting configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation to an agent configured within the on-premises network associated with the customer; receiving a request for querying information associated with a resource existing within the virtual cloud network (VCN) associated with the customer, the query being sent by the external resource existing within the on-premises network, the external resource being provisioned with a logical interface, and the plurality of operations further include establishing a connection between the logical interface provisioned for the external resource existing within the on-premises network and the virtual network interface card (VNIC) created for the external resource representation within the virtual cloud network; transmitting the request to the resource existing within the virtual cloud network via the established connection; and obtaining a result corresponding to the request via the established connection. A computer program comprising

18. The computer program according to claim 17, wherein the agent is configured to provision the logical interface of the external resource existing within the on-premises network at least partially based on the configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation.

19. Provisioning the logical interface of the external resource includes the agent assigning the virtual Internet Protocol (IP) address of the virtual network interface card (VNIC) of the external resource representation to the logical interface, the computer program according to claim 18.

20. The configuration information corresponding to the virtual network interface card (VNIC) of the external resource representation includes the virtual Internet Protocol (IP) address of the virtual network interface card (VNIC), the fully qualified domain name associated with the computing instance associated with the virtual network interface card (VNIC), and the cloud identifier of the virtual cloud network associated with the customer, the computer program according to any one of claims 17 to 19.

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