Method and system for achieving network address translation

Abstract

The invention discloses a method and a system for achieving network address translation, which relates to the technical field of network communication. The method comprises the steps of: S1, receiving a current datagram requiring network address port translation, achieving translation of an inner network IP (internet protocol) address and a public network IP (internet protocol) address of the current datagram, wherein the public network IP address of the current datagram comprises N port queues, and N is an integer greater than 1; S2, selecting one port sequence in the N port queues according to an outer network IP address of the current datagram, and selecting a port which is not distributed in the selected port queue as a public network port number of the current datagram. According to the invention, judgment of a target IP is increased on a conversion method of PAT (port address translation); the same port number can be adopted as to different resources; multiplexing of the port is achieved; the different resources are expanded for N times relatively to the port resource, and the datagram is prevented from being abandoned due to exhausting of the port resource.

Description

technical field [0001] The invention relates to the technical field of network communication, in particular to a method and system for realizing network address translation. Background technique [0002] The Network Address Translation (NETWORK ADDRESS TRANSLATION, NAT) protocol realizes the mutual conversion between the IP address in the private network and the IP address in the public network, and the private network address corresponds to the public network address one by one. [0003] Network Address Port Translation (PORT ADDRESS TRANSLATION, PAT) is a variant of NAT, which allows multiple private network addresses to be mapped to the same public network address. It can also be called "many-to-one address translation" or "address multiplexing". . PAT maps IP addresses and port numbers at the same time. The source addresses of datagrams from different private network addresses can be mapped to the same public network address, but the port numbers of these datagrams from...

AI Technical Summary

Problems solved by technology

In this scheme, due to the limited length of the port queue (port value ranges from 0 to 65535), the number of private network addresses that can be used for conversion of a public network address is limited, and it is easy to run out of port resources in actual use resulting in datagrams being discarded

Images