Intel ER8100STUS - Express 8100 Router, Reference Manual

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Reference.bok : Chapter08 62 Wed Apr 22 10:58:08 1998
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IP Concept
IP Routing
is restarted following every communication. After 1 hour, the address can be re-
used for another address translation if required but remains available until it is
reused for another translation.
Static Mapping to
internal addresses for
Dynamic Mapping
When using Dynamic Mapping, only internal devices can initiate communica-
tions with external devices. To make specific internal addresses permanently ac-
cessible to the external network, Static Mapping to these addresses can be
established. Static Mapping assign a fixed translation address to an internal de-
vice address so that communications can also be initiated to the device from the
external network.
Examples of Use
Simple address
translation
A common application of NAT is simple address translation between internal
and external network addresses. This may be done, for example, to avoid renum-
bering an entire network which is using an unreserved network number, to be
connected to network which requires reserved network numbers (for example the
internet) assigned by InterNIC (see
“Address assignment”, p. 47 ).
Address translations between networks of the same size is described in “Static
Mapping”, p. 60 . Address translations between networks of different size is de-
scribed in “Dynamic Mapping”, p. 60 .