Network Address tanslation

NAT (Network Address Translation)
  • It is estimated that there are over 20 billion devices connected to the Internet (and growing)
    • IPv4 supports around 4.29 billion addresses
  • The address space for IPv4 is exhausted
    • There are no available addresses to assign
  • How does it all work?
    • Network Address Translation
  • This isn't the only use of NAT
    • NAT is handy in many situations
Port Forwarding
  • 24x7 access to a service hosted internally
    • Web server, gaming server, security system, etc.
  • External IP/port number maps to an internal IP/port
    • Does not have to be the same port number
  • Also called Destination NAT or Static NAT
    • Destination address is translated from a public IP to a private IP
    • Does not expire or timeout
RFC 1918 Private IPv4 Addresses

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