3Com 3C840 Network Router User Manual


 
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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
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