what is Network Address Translation

tags: learning networking

content

  • when a ip packet passes a gateway, the gateway modifies the ip packet’s src IP, dest IP, src port, dest port, one or multiple of the 4 elements
  • Address Translation it’s not just simple forwarding, there’s translation, aka transformation, or modification
  • a NAT table will be used to keep track of what have been modified, and how to modify the returning packets, so that they go back to the original sender.

functions:

  • solves the issue of IPv4 exhaustion
  • protects internal servers by hiding them behind a NAT (not exposing their IP to public network)

side effects:

  • prevents p2p connection
  • more operation during packet transmission, adds delay to the process

up

NAT & NAT traversal Network Address Translation NAT

down

source-nat dest-nat

reference