Nat--network Address Translator

Defined

NAT is used to use a private address in the local network, and instead uses the technology of the global IP address when connecting to the Internet. In addition to converting IP addresses, napt (Network address Ports Translator) technology, which can convert TCP and UDP port numbers, enables communication with multiple hosts with a single global IP address. Often referred to as NAT, mostly refers to napt. NAPT is also called IP spoofing or multi NAT.

NAT (NAPT) is actually a technology developed for IPV4 that are facing an address depletion. However, in IPv6, Nat is used in order to improve network security, and NAT-PT is often used in communication between IPV4 and IPV6.

Working mechanism

In communication using TCP or UDP, only the destination address, source address, destination port, source port, and protocol type (TCP or UDP) five items are considered to be the same communication connection. It is the napt that is used at this time.

Nat-pt

Nat-pt the first technique of converting the IPV6 header to the first of the IPv4. With this technique, hosts with only IPV6 addresses can communicate with other hosts of the IPV4 address.

Excerpt from: TCP/IP Detailed

Nat--network Address Translator