User's Manual

SPEEDLAN 8500 Series Installation and Operation User Guide
7-10 Setting Up the IP Addresses (IP Host Setup)
What is NAT?
Network Address Translation (NAT) is the conversion of an Internet Protocol address (IP address)
used within one network to a different IP address within another network. One network is designated
the inside network and the other is the outside network.
Network Address Translation (NAT) occurs when there is a translation among an Internet Protocol (IP
address) used within one network (designated as inside network) to a different IP addresses within
another network (designated as outside network). Network Address Translators (NATs) allow
companies to decrease the number of global IP addresses. This enables companies to communicate
with other devices on the Internet using a single IP address (or more than one IP address).
For example, a company can provide its clients with one IP address, allowing access to the
company's firewall only. This IP address is not a "real" address on the company's internal network, but
it is successfully translated to the correct IP location through NAT (i.e., NAT router). Therefore, the
company controls access through firewalls and provides multiple IP addresses to outside customers
without excessive limited resources, or "global" Internet IP protocols.