3Com OfficeConnect 3C840, User Manual

Page: 183 / 222

C
A
DDRESS
T
RANSLATION
T
UTORIAL
Overview
Public IP addresses are registered and can be used within a public
network, such as the Internet. Due to the limitation of IP version 4
address space and the growth of the Internet, public addresses are
becoming more scarce.
One solution to this problem is to use private addresses on small LANs
and to use Address Translation when accessing devices on the public
network. Address Translation changes a private address to a public
address at the gateway of a public network.
There are two types of address translation, Network Address Translation
and Port Address Translation:
■
“Network Address Translation (NAT)”
■
“NAT Example”
■
“Dynamic NAT”
■
“Static NAT”
■
“Port Address Translation (PAT)”
■
“PAT Example”
■
“Dynamic PAT”
■
“Static PAT”
■
“Default PAT”
840ug.book Page 1 Friday, July 7, 2000 2:23 PM