Methods for implementing DHCP without IP relay in PON networks

Abstract

This invention discloses a method for implementing DHCP relay without IP address in a PON network, comprising the following steps: S1, the OLT device enables and configures DHCP snooping; S2, the OLT device enables DHCP relay for the client-side VLAN and specifies the Server IP, without creating a Layer 3 VLAN interface or configuring an IP address for the client-side VLAN; S3, the OLT device processes request packets sent by the client side. If the OLT device has not configured the client-side VLAN if interface IP, the source IP is filled with the Server-side VLAN if interface IP; if the giaddr field is 0, it is filled with the same as the source IP and forwarded; otherwise, no changes are made, and the packet is forwarded directly; S4, the DHCP snooping binding table is updated. This invention cleverly completes DHCP relay forwarding using the DHCP snooping function without configuring IP addresses, simplifying user network setup and configuration, and improving network security.

Description

Technical Field

[0001] This invention relates to the field of communications, and more particularly to a method for implementing DHCP without IP relay in a PON network. Background Technology

[0002] An OLT (Optical Line Terminal) device is an important central office device that can connect to aggregation layer switches and routers via network cables, converting signals into optical signals and interconnecting with the user-end optical splitter via a single optical fiber. It enables control, management, and ranging of the user-end ONU (Optical Network Unit) devices. Like the ONU device, it is an integrated optoelectronic device. Currently, OLTs play a crucial role in network topology, and Layer 3 functionality has become standard on various OLT devices. This includes VLAN interface management system, routing management system, ARP management system, IPv6 protocol, NDP management system, DHCP Server protocol, DHCP Client protocol, and DHCP Snooping protocol.

[0003] A PON (Passive Optical Network) system typically consists of two parts: an OLT and an ONU.

[0004] DHCP (Dynamic Host Configuration Protocol) is commonly used in large local area network environments. Its main function is to centrally manage and allocate IP addresses, enabling hosts in the network environment to dynamically obtain information such as IP addresses, gateway addresses, and DNS server addresses, thereby improving address utilization. DHCP is a common service application in PON networks. When a user configures a DHCP client on the ONU terminal to request an IP address from the server upstream of the OLT, and the user is using a Layer 3 network deployment, they typically configure DHCP-relay on the OLT. This requires occupying a Layer 3 interface on the OLT and configuring an IP address. However, in reality, the OLT interface may be far from the client, or for security reasons, the user may prefer not to create this Layer 3 interface and configure an IP address.

[0005] Before OLT devices support IP relay-less operation, a Layer 3 interface needs to be created and an IP address configured in the OLT device before DHCP relay forwarding can be performed. Figure 1 As shown.

[0006] Another implementation method: Instead of creating a Layer 3 interface in the OLT device, add another device supporting DHCP Relay in the upstream network of the OLT to handle forwarding, such as... Figure 2 As shown.

[0007] Regardless of which of the above solutions is chosen, the networking setup becomes complex or increases costs. Summary of the Invention

[0008] The main objective of this invention is to enable DHCP relay without configuring Layer 3 interfaces and IP addresses on the OLT, thereby greatly simplifying the user's network setup and configuration, and improving network security.

[0009] The technical solution adopted in this invention is:

[0010] A method for implementing DHCP without IP relay in a PON network is provided, including the following steps:

[0011] S1 and OLT devices are configured to enable DHCP snooping, listen to VLANs and trust ports, and configure option 82 to add an identifier to client requests connecting to the trust port.

[0012] S2 and OLT devices enable DHCP Relay for customer-side VLANs and specify a Server IP. No Layer 3 VLAN interfaces are created or IP addresses are configured for customer-side VLANs.

[0013] The S3 and OLT devices process the request packets sent by the client side as follows:

[0014] If the OLT device is not configured with the client-side VLAN if interface IP, then fill the source IP with the server-side VLAN if interface IP;

[0015] If the giaddr field is 0, fill it with the VLAN if interface IP on the server side and forward it; otherwise, do not change it and forward it directly.

[0016] S4. Update the DHCP snooping binding table and create a new DHCP snooping binding table entry for the client device that sent the request packet.

[0017] Following the above technical solution, step S3 also includes the OLT device processing the server-side reply packet, as detailed below:

[0018] Check the giaddr field in the response packet;

[0019] If it is a Server-side VLAN if IP, it is considered that there is no IP for Relay configuration. The DHCP snooping binding table is used to look up the user-side VLAN, modify the packet source IP to the Server-side VLAN if IP, and forward it according to the user-side VLAN.

[0020] After receiving the Ack message, the DHCP module updates the DHCP snooping binding table, recording complete information including IP address and lease details.

[0021] Following the above technical solution, in step S3, when the OLT device processes the request packet sent by the client side, if the OLT device has configured the client-side VLAN if interface IP, then the source IP will be filled with the Client-side VLAN if interface IP.

[0022] If the giaddr field is 0, it is filled with the VLAN if interface IP on the Client side and forwarded; otherwise, it is not changed and forwarded directly.

[0023] Following the above technical solution, in step S3, when the OLT device processes the server-side reply packet, if it is a Client-side VLAN if IP, it is assumed that the Relay configuration is performed through the Layer 3 port, and the packet is forwarded directly according to the Client-side VLAN if attribute.

[0024] Following the above technical solution, in step S3, when the OLT device processes the server-side reply packet, if it is not the IP address of the VLAN IF interface of this device, it will look up the next hop in the device routing table and forward it.

[0025] Following the above technical solution, the method further includes step S5: the OLT device periodically obtains the next-hop information of the server from the routing module through the DHCP module.

[0026] Following the above technical solution, the ONT is configured in bridge mode and does not act as a DHCP client. The user's PC acts as a client and accesses the network through the ONT via the PON port of the OLT device.

[0027] The present invention also provides a system for implementing DHCP without IP relay in a PON network, including a DHCP server, an OLT device, an optical network unit (ONU), and a client;

[0028] The client is used to initiate a DHCP discover message, which is sent uplink from the ONT device to the PON port of the OLT, and requests an IP address from the DHCP server located upstream of the OLT device through the PON network;

[0029] The OLT device is used to enable DHCP snooping, configure the listening VLAN and trusted port, and configure option 82 to add an identifier to client requests connecting to the trusted port; it enables DHCP Relay for the client-side VLAN and specifies the Server IP; the client-side VLAN does not create a Layer 3 VLAN interface or configure an IP address; the OLT device's processing flow for request packets sent from the client side is as follows:

[0030] If the OLT device does not have a configured VLAN if interface IP on the client side, then fill the source IP with the VLAN if interface IP on the server side;

[0031] If the giaddr field is 0, fill it with the VLAN if interface IP on the server side and forward it; otherwise, do not change it and forward it directly.

[0032] At the same time, the DHCP snooping binding table is updated, and a new DHCP snooping binding table entry is created for the client device that sent the request packet.

[0033] The present invention also provides a computer storage medium, characterized in that it stores a computer program that can be executed by a processor, the computer program executing the method for implementing DHCP without IP relay in a PON network according to the above technical solution.

[0034] The beneficial effects of this invention are as follows: This invention enables DHCP Relay on the client-side VLAN via the OLT device and assigns a Server IP. The client-side VLAN does not create a Layer 3 VLAN interface or configure an IP address. When a client sends a request packet, if the OLT device does not have a configured client-side VLAN if interface IP, the source IP is filled with the Server-side VLAN if interface IP; the giaddr field is used to fill in the VLAN if interface IP of either the Server or Client side; and the DHCP snooping binding table is updated simultaneously. For server-side response packets, the giaddr field is checked to determine whether it is a Server-side VLAN if IP, a Client-side VLAN if IP, or a non-local VLAN if interface IP, and the packet is forwarded accordingly. This achieves DHCP-relay network deployment without Layer 3 interfaces or IP addresses. Therefore, this patent breaks with conventional DHCP Relay schemes. Without configuring IP addresses, it cleverly completes DHCP Relay forwarding using DHCP snooping functionality, simplifying user network setup and configuration, and improving network security. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a typical DHCP-Relay network diagram—a schematic diagram of configuring the relay through a Layer 3 interface;

[0037] Figure 2 This is a typical DHCP-Relay network diagram – a schematic diagram of a network using an external relay device;

[0038] Figure 3 This is a DHCP-Relay network diagram for an embodiment of the present invention that does not use a Layer 3 port;

[0039] Figure 4 This is a flowchart of the OLT device receiving and processing request messages;

[0040] Figure 5 This is a flowchart illustrating the process of receiving and processing reply messages by an OLT device according to an embodiment of the present invention.

[0041] Figure 6 This is a method flow for implementing DHCP without IP relay in a PON network according to an embodiment of the present invention. Figure 1 ;

[0042] Figure 7 This is a method flow for implementing DHCP without IP relay in a PON network according to an embodiment of the present invention. Figure 2 . Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0044] like Figure 3 As shown, the DHCP relay system in the PON network of this invention mainly implements the DHCP-Relay function through the OLT device without IP address, including a DHCP server, OLT device, optical network unit (ONU), and client. After the ONU successfully registers on the OLT device, the user PC (client) requests an IP address from the DHCP server located upstream of the OLT through the PON network composed of the ONU and OLT.

[0045] This invention primarily provides a method for DHCP relay on an OLT without configuring a Layer 3 interface and IP address. For example... Figure 6 As shown, the method mainly includes the following steps:

[0046] S1 and OLT devices enable DHCP snooping, configure the listening VLAN and trusted port, and configure option 82 to add an identifier to client requests connecting to the trusted port.

[0047] The S2 and OLT devices enable DHCP Relay for the customer-side VLANs and specify the Server IP. The customer-side VLANs do not create Layer 3 VLAN interfaces or configure IP addresses.

[0048] The S3 and OLT devices analyze and process request packets from the client side and response packets from the server side.

[0049] S4. After receiving the Ack message, the DHCP module updates the DHCP snooping binding table, recording complete information including IP address and lease details.

[0050] like Figure 6 As shown, the method also includes the following steps: S5, the DHCP module periodically obtains the next-hop information of the server from the routing module.

[0051] Step S3 mainly includes the following steps:

[0052] S31. The processing of client-side request packets mainly involves configuring the VLAN if interface IP based on whether the client-side VLAN if interface IP is configured, and performing different configurations based on the giaddr field.

[0053] S32. The processing of server-side reply packets mainly involves checking the giaddr field in the message to determine whether it is the server-side VLAN if IP, the client-side VLAN if IP, or an interface IP that is not the local device's VLAN IF interface.

[0054] like Figure 4 As shown, step S31 mainly includes the following steps:

[0055] S311. If the device does not have a client-side VLAN if interface IP configured, then fill the source IP with the server-side VLAN if interface IP and forward it.

[0056] S312. If the giaddr field is 0, then fill the giaddr field with the Server-side VLAN if interface IP (i.e., the value of the source IP) and then forward; otherwise, do not change the giaddr field and forward directly.

[0057] S313. If the device has a configured client-side VLAN if interface IP, then fill the source IP with the client-side VLAN if interface IP and forward it.

[0058] S314. If the giaddr field is 0, then fill the giaddr field with the Client-side VLAN if interface IP (i.e., the value of the source IP), and then forward the data; otherwise, do not change the giaddr field and forward the data directly.

[0059] The DHCP module (software function module: including DHCP client, DHCP relay protocol, DHCP snooping function) of the S315 and OLT devices simultaneously updates the DHCP snooping binding table, creating a new DHCP snooping binding table for the requesting device, recording information such as MAC, VLAN, and option82.

[0060] like Figure 5 As shown, step S32 mainly includes the following steps:

[0061] S321. If it is a Server-side VLAN if IP, it is considered that there is no IP for Relay configuration. Then, the DHCP snooping binding table is used to look up the user-side VLAN, modify the packet source IP to the Server-side VLAN if IP, and forward it according to the user-side VLAN.

[0062] S322. If it is a Client-side VLAN if IP, it is assumed that the Relay is configured through a Layer 3 port, and forwarding is performed directly according to the Client-side VLAN if attribute.

[0063] S323. If the IP address is not the VLAN IF interface IP address of this device, look up the next hop in the device routing table and forward it.

[0064] The above process enables DHCP-relay network deployment without Layer 3 interfaces and IP addresses, which can greatly simplify network setup and configuration for users and improve network security.

[0065] In this embodiment of the invention, the upstream network of the OLT is connected to the DHCP server using VLANIF. The OLT is configured as VLANIF1000, IP10.11.1.5, and the DHCP server IP is 10.11.1.1.

[0066] Enable DHCP snooping on the OLT device, configure the listening VLAN and trusted port, and configure option 82 to add an identifier to client requests connecting to the trusted port.

[0067] The DHCP server uses the option 82 identifier to distinguish the validity of clients and assigns IP addresses to devices requesting IP addresses.

[0068] The ONT is configured in bridge mode and does not act as a DHCP client. The user's PC acts as a client and accesses the network through the ONT via the PON port of the OLT device.

[0069] The OLT device enables DHCP Relay for VLAN 201 on the client side, specifies the Server IP as 10.11.1.1, and does not create a Layer 3 VLAN interface for the client side VLAN.

[0070] The user PC first initiates a DHCP discover message, which is then sent uplink from the ONT to the PON port of the OLT.

[0071] When the OLT device receives the discover message, it performs DHCP snooping and adds option 82 information.

[0072] The DHCP module of the OLT device checks the discover message and finds that the client-side VLAN does not have an IP address. Therefore, it fills the source IP with the IP address of the uplink VLANIF connected to the DHCP server side, which is 10.11.1.5. At the same time, it fills the giaddr field with the IP address of the uplink VLANIF connected to the DHCP server side, which is 10.11.1.5, and forwards it out from the uplink port.

[0073] When the DHCP server receives the message, it uses the option82 identifier to distinguish the validity of the client. If successful, it sends an offer packet to provide an IP address.

[0074] When the OLT device receives the offer packet from the server, it checks the giaddr field in the packet and finds that it is the VLAN if IP of the server side. Then it looks up the DHCP snooping binding table, obtains the client side VLAN 201, and fills the source IP with the IP address of the uplink port VLAN IF connected to the DHCP server side, 10.11.1.5, and forwards it from the user side VLAN 201.

[0075] When the user's PC receives the offer message, it continues the request process. Subsequent messages follow the same process and are forwarded normally.

[0076] After the above process, the client-side PC can be successfully assigned an IP address through the OLT device relay.

[0077] This application also provides a computer-readable storage medium, such as flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, server, app store, etc., which stores a computer program. When the program is executed by a processor, it performs corresponding functions. The computer-readable storage medium of this embodiment is used to implement the DHCP without IP relay method in the PON network of the method embodiment when executed by a processor.

[0078] Note that the example above uses a single DHCP server and a single DHCP client for networking. In actual deployment, it is not limited to a single configuration. There can be n VLANs and clients under one PON port, and the DHCP server can also connect to multiple VLANs to realize a multi-point to multi-point service forwarding model.

[0079] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for implementing DHCP without IP relay in a PON network, characterized in that, Includes the following steps: S1 and OLT devices are configured to enable DHCP snooping, listen to VLANs and trust ports, and configure option 82 to add an identifier to client requests connecting to the trust port. S2 and OLT devices enable DHCP Relay for customer-side VLANs and specify a Server IP. No Layer 3 VLAN interfaces are created or IP addresses are configured for customer-side VLANs. The S3 and OLT devices process the request packets sent by the client side as follows: If the OLT device is not configured with a VLAN if interface IP on the client side, then the source IP will be filled with the VLAN if interface IP on the server side and forwarded. If the giaddr field is 0, then fill it with the Server-side VLAN if interface IP and forward it; Otherwise, do not make any changes and forward directly; S4. Update the DHCP snooping binding table and create a new DHCP snooping binding table entry for the client device that sent the request packet.

2. The method for implementing DHCP without IP relay in a PON network according to claim 1, characterized in that, Step S3 also includes the OLT device's processing of the server-side reply packet, as detailed below: Check the giaddr field in the response packet; If it is a Server-side VLAN if IP, it is assumed that there is no IP for Relay configuration. The user-side VLAN is looked up through the DHCP snooping binding table, the packet source IP is modified to the Server-side VLAN if IP, and forwarded according to the user-side VLAN.

3. The method for implementing DHCP without IP relay in a PON network according to claim 1, characterized in that, In step S3, when the OLT device processes the request packet sent by the client, if the OLT device has a configured client-side VLAN if interface IP, the source IP will be filled with the client-side VLAN if interface IP. If the giaddr field is 0, it is filled with the Client-side VLAN if interface IP and forwarded; Otherwise, leave it as is and forward it directly.

4. The method for implementing DHCP without IP relay in a PON network according to claim 2, characterized in that, In step S3, when the OLT device processes the server-side reply packet, if it is a Client-side VLAN if IP, it assumes that the Relay configuration is performed through the Layer 3 port and forwards it directly according to the Client-side VLAN if attribute.

5. The method for implementing DHCP without IP relay in a PON network according to claim 2, characterized in that, In step S3, when the OLT device processes the reply packet from the server side, if the packet is not the IP address of the VLAN IF interface of this device, it will look up the next hop in the device routing table and forward it.

6. The method for implementing DHCP without IP relay in a PON network according to claim 1, characterized in that, The method also includes step S5: the OLT device periodically obtains the next-hop information of the server from the routing module through the DHCP module.

7. The method for implementing DHCP without IP relay in a PON network according to claim 1, characterized in that, The ONT is configured in bridge mode and does not act as a DHCP client. The user's PC acts as a client and accesses the network through the ONT via the PON port of the OLT device.

8. A system for implementing DHCP without IP relay in a PON network, characterized in that, This includes a DHCP server, OLT equipment, optical network unit (ONU), and clients; The client is used to initiate a DHCP discover message, which is sent uplink from the ONT device to the PON port of the OLT, and requests an IP address from the DHCP server located upstream of the OLT device through the PON network; The OLT device is used to enable DHCP snooping, configure the listening VLAN and trusted port, and configure option 82 to add an identifier to client requests connecting to the trusted port; it enables DHCP Relay for the client-side VLAN and specifies the Server IP; the client-side VLAN does not create a Layer 3 VLAN interface or configure an IP address; the OLT device's processing flow for request packets sent from the client side is as follows: If the OLT device does not have a client-side VLAN if interface IP configured, the source IP will be filled with the server-side VLAN if interface IP and then forwarded. If the giaddr field is 0, then fill it with the Server-side VLAN if interface IP and forward it; Otherwise, do not make any changes and forward directly; At the same time, the DHCP snooping binding table is updated, and a new DHCP snooping binding table entry is created for the client device that sent the request packet.

9. The system for implementing DHCP without IP relay in a PON network according to claim 8, characterized in that, The OLT device processes server-side response packets as follows: Check the giaddr field in the response packet; If it is a Server-side VLAN if IP, it is assumed that there is no IP for Relay configuration. The user-side VLAN is looked up through the DHCP snooping binding table, the packet source IP is modified to the Server-side VLAN if IP, and forwarded according to the user-side VLAN.

10. A computer storage medium, characterized in that, It contains a computer program that can be executed by a processor, which performs the method for implementing DHCP without IP relay in a PON network according to any one of claims 1-7.

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