Persistent NAT Mapping for External Host Connectivity
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Solution Overview
Problem
Current Network Address Translation (NAT) systems temporarily map internal private IP addresses to public IP addresses, limiting external hosts' ability to initiate connections with internal hosts beyond a single session, as the mappings are typically temporary and do not persist.
Innovation Solution
Implementing a method where an internal host requests and receives a public IP address through an API, which is then mapped and communicated to a NAT system, allowing the internal host to make the public IP address available to external hosts, enabling persistent mappings for incoming connections via a network element like a DNS server.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If temporary NAT mapping is used, then IP address sharing is enabled, but external hosts cannot initiate connections beyond a single session
Solution Approach 1:
The internal host proactively requests and obtains a public IP address mapping before external connections are needed. The mapping is established in advance and made available to external hosts through DNS or other resolution mechanisms, enabling connections to be initiated at any time without waiting for session resumption.
Solution Approach 2:
A DNS server or similar intermediary is introduced to resolve the public IP address to the internal host. This intermediary maintains the mapping information and facilitates the connection establishment process, allowing external hosts to reach internal hosts consistently through the public address without direct NAT session management.
2Ease of operation
If public IP address is assigned to internal host, then external access is enabled, but the advantage of shared IP address usage is lost
Solution Approach 1:
The system segments IP address usage into two distinct spaces: private IP addresses for internal network communication and public IP addresses for external accessibility. Internal hosts maintain their private addresses for shared usage, while obtaining public addresses only when external access is required, thus segmenting the address allocation based on functional needs.
Solution Approach 2:
The solution adds a dimensional layer by introducing public IP addresses as an additional addressing dimension alongside private IP addresses. Internal hosts operate in the private address space for efficient sharing, while the public address space provides external accessibility. The NAT mapping connects these two dimensional spaces, allowing both efficiency and accessibility to coexist.
Data Source
AI summary
Network address translation allows hosts within a private network (“internal hosts”) to access the Internet through a single or a limited number of public IP addresses. When an internal host accesses the Internet, NAT translates the internal host's private IP address into a temporary public IP address for a given session. A method and media are provided for enabling a host external to the private network (“external host”) to initiate communication with an internal host. The internal host requests that a global address be mapped to its private address. The internal host receives the global address and sends it to a server where it is available to an external host. The mapping between the private address and the global address is maintained in a NAT system so that an inbound connection request from an external host can be forwarded to the internal host.