Cabletron Systems 9032578-05 - page 245

SmartSwitch Router User Reference Manual 219
Chapter 16
Network Address
Translation
Configuration
Guide
Overview
Note: Some commands in this facility require updated SSR hardware. Please refer to
Appendix A for details.
Network Address Translation (NAT) allows an IP address used within one network to be
translated into a different IP address used within another network. NAT is often used to
map addresses used in a private, local intranet to one or more addresses used in the
public, global Internet. NAT provides the following benefits:
• Limits the number of IP addresses used for private intranets that are required to be
registered with the Internet Assigned Numbers Authority (IANA).
• Conserves the number of global IP addresses needed by a private intranet (for
example, an entity can use a single IP address to communicate on the Internet).
• Maintains privacy of local networks, as internal IP addresses are hidden from public
view.
With NAT, the local network is designated the inside network and the global Internet is
designated the outside network. In addition, the SSR supports Port Address Translation
(PAT) for either static or dynamic address bindings.