Port Address Translation (PAT)

Port Address Translation (PAT) An architecture diagram generated by Archify. Host A · 10.0.0.2:1234 · Internal Network Host A 10.0.0.2:1234 Host B · 10.0.0.3:1234 · Internal Network Host B 10.0.0.3:1234 198.51.100.1 · IP:port translation · NAT Router (PAT) 198.51.100.1 IP:port translation Server · 203.0.113.5:80 · Internet Server 203.0.113.5:80 10.0.0.2:1234 10.0.0.3:1234 198.51.100.1:5000 198.51.100.1:5001 Internal Network NAT Router (PAT) Internet Legend Frontend Security External

How PAT works

  • • Translates each internal host's IP:port pair to a different port on a single public IP
  • • Multiple internal hosts share one public IP, distinguished by port number
  • • Limited by the number of available ports (about 65,000)