IP Services

NAT translates private (RFC 1918) addresses to public addresses, conserving the limited IPv4 space and hiding internal addressing from the outside.

The private address assigned to an inside host as it appears inside the local network before translation.

The public, routable address that represents an inside host to the outside world after translation.

Outside global is the real public address of an outside host; outside local is how that outside host appears to the inside network (often the same unless destination NAT is used).

A fixed one-to-one mapping between one inside local and one inside global address; used so internal servers are reachable from outside at a consistent public IP.