Internet Protocols - CCIE Routing and Switching Exam Certification Guide - page 298

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Inside global address —Translated IP address of the device that resides in the Internal
network. The public network uses this address.

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Outside global address —Real IP address of a device that resides in the Internet, outside
of the stub domain.

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Outside local address —Translated IP address of the device that resides in the Internet.
The stub domain uses this address.

Figure 6-16 illustrates the previous terms. The real IP address of the host in the stub network is
192.168.10.100, which is the inside local address. The inside local address is translated into the
inside global address (200.100.10.100) at the NAT router. Hosts located in the Internet have
their real IP address (outside global address) translated. For example, 30.100.2.50 is translated
into the outside local address of 192.168.100.50.

NAT Terminology Example

Figure 6-16

Stub Network Public Network

NAT Router

Inside global address: 200.100.10.100

Inside local address: 192.168.10.100

Outside local address: 192.168.100.50 Outside global address: 30.100.2.50

Configuring NAT on Cisco Routers
To configure IP NAT for simple dynamic NAT, performed the following steps:

Configure interfaces to be marked as inside or outside. Inside interfaces
reside in the stub network, and outside interfaces reside in the public
network. Configure inside interfaces with the ip nat inside command.
Configure outside interfaces with the ip nat outside command.

Step 1

Configure an address pool to dynamically assign inside global addresses. You
can use a range of IP addresses for dynamic translations that are specified
with a starting and ending IP address by using the ip nat pool name start-ip
end-ip netmask netmask command.

Step 2

Enable the translation of inside local addresses with the ip nat inside source
[ list acl pool name ] command. The name is the same name specified in Step
2. The acl access list specifically defines the inside local addresses that are
translated.

Step 3

Example 6-8 shows a sample configuration for Figure 6-17, which translates the inside
192.168.10.0/24 and 192.168.11.0/24 addresses by using a global pool of 200.100.100.0/24.
Outside global addresses are not translated.