NAPT (Network Address Port Translation) is a variation of NAT (Network Address Translation). In Computer networking network address translation (NAT is the process of modifying Network address information in datagram packet headers while in transit across It is also referred to as PAT (Port Address Translation) by Cisco, and RAPT (Reverse Address and Port Translation) or RAT in some implementations. Port Address Translation (PAT is a feature of a network device that translates TCP or UDP communications made between hosts on a private network and hosts