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At
a minimum, IP routing and appropriate IP addresses must be
configured on the router. To configure overlapping address
translation, perform the following steps:
-
Define the standard IP
access list for the inside network, as discussed in the “Dynamic NAT Configuration” section.
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Define an IP NAT pool for the inside network by using the
ip nat pool
name start-ip end-ip {netmask netmask | prefix-length prefix-length}
command.
Define an IP NAT pool for the outside network by using the
ip nat pool
name start-ip end-ip {netmask netmask | prefix-length prefix-length}
command.
Define mapping between the
access list and the inside global pool by using the
ip nat inside source list
access-list-number pool
name [overload]
command.
Define mapping between the
access list and the outside local pool by using the
ip nat outside source list
access-list-number pool
name
command.
Enable NAT on the appropriate interface, as previously discussed, by using the
ip nat {inside | outside}
command.
Example
shows a sample configuration of NAT used for translating overlapping addresses. In this example, one single router is responsible for performing the translation for inside and outside traffic. The corresponding topology is shown in Figure
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Lab
Activity |
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Configure an ISDN connection between Bread
company router and the Butter company router,
and configure it so that the two networks
which have the same IP addresses can
communicate together. To accomplish the
communication we will configure dynamic
overlapping network address translation. |
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