Intermediate System to Intermediate System | 515Sample ConfigurationThe following configurations are examples for enabling IPv6 IS-IS. These are not comprehensivedirections. They are intended to give you a some guidance with typical configurations.You can copy and paste from these examples to your CLI. Be sure you make the necessary changes tosupport your own IP Addresses, Interfaces, Names, etc.Figure 23-10 is a sample configuration for enabling IPv6 IS-IS. Figure 23-13 illustrates the topologycreated with that CLI configuration.IPv6 IS-IS routes can be configured in one of the following three different methods:• Congruent Topology: Both IPv4 and IPv6 addresses must be configured on the interface. Thecommands ip router isis and ipv6 router isis must be enabled on the interface. You must enable thewide-metrics parameter in the router isis configuration mode.• Multi-topology: The IPv6 address must be configured. Configuring the IPv4 address is optional. Thecommand ipv6 router isis must be enabled on the interface. If IPv4 is configured, the command ip routerisis must also be enabled. In the router isis configuration mode, enable multi-topology underaddress-family ipv6 unicast.• Multi-topology Transition: The IPv6 address must be configured. Configuring the IPv4 address isoptional. The command ipv6 router isis must be enabled on the interface. If IPv4 is configured, thecommand ip router isis must also be enabled. In the router isis configuration mode, enablemulti-topology transition under address-family ipv6 unicast.SNote: Only one IS-IS process can run on the router, even if both IPv4 and IPv6 routing isbeing used.SNote: Whenever ISIS configuration changes are made, the IS-IS process must be cleared(re-started) using the clear isis command. The clear isis command must include the tag for theISIS process. The example below shows the response from the router:FTOS#clear isis *% ISIS not enabled.FTOS#clear isis 9999 *
