EIGRP for IPv6 uses a different method to enable an interface for EIGRP. Instead of using the network router configuration mode command to specify matching interface addresses, EIGRP for IPv6 is configured directly on the interface.
Use the following interface configuration mode command to enable EIGRP for IPv6 on an interface:
Router(config-if)# ipv6 eigrp autonomous-system
The autonomous-system value must be the same as the autonomous system number used to enable the EIGRP routing process. Similar to the network command used in EIGRP for IPv4, the ipv6 eigrp interface command:
- Enables the interface to form adjacencies and send or receive EIGRP for IPv6 updates
- Includes the prefix (network) of this interface in EIGRP for IPv6 routing updates
Figure 1 shows the configuration to enable EIGRP for IPv6 on routers R1 and R2 interfaces. Notice the message following the serial 0/0/0 interface in R2:
%DUAL-5-NBRCHANGE: EIGRP-IPv6 2: Neighbor FE80::1 (Serial0/0/0) is up: new adjacency
This message indicates that R2 has now formed an EIGRP-IPv6 adjacency with the neighbor at link-local address FE80::1. Because static link-local addresses were configured on all three routers, it is easy to determine that this adjacency is with router R1 (FE80::1).
Use the Syntax Checker in Figure 2 to enable EIGRP for IPv6 on R3’s interfaces.
Passive Interface with EIGRP for IPv6
The same passive-interface command used for IPv4 is used to configure an interface as passive with EIGRP for IPv6. As shown in Figure 3, the show ipv6 protocols command is used to verify the configuration.