Configuring IS-IS

Configuring IS-IS
An important item for you to note is to make sure the IOS your routers are running supports
CLNS. Remember, even in an IP-only environment, IS-IS still sends CLNS PDUs. If your routers
are not running an IOS that supports CLNS, you will not be able to configure IS-IS.
Figure 7.4 displays a network with three areas and five routers.