How to prevent duplicate EIGRP router IDs

When routes are redistributed into the Enhanced Interior Gateway Routing Protocol (EIGRP), external routes are tagged with the Originating router field.

This field is the router ID of the Cisco router redistributing the routes.

The router ID is selected from the highest IP address assigned to a loopback interface.

If no loopback addresses are configured, the router ID is selected from the highest IP address assigned to any other interface.

When multiple Cisco routers use the same router ID, the routes are not installed in the routing table, resulting in routing failures.

To prevent duplicate router IDs, ensure that the IP address on the interface being used as the router ID is unique between the EIGRP routers.

To manually configure a router ID for EIGRP, issue the eigrp router-id command from the router configuration mode of EIGRP.

For more information refer to:

Preventing Duplicate EIGRP Router IDs

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• Cisco
• LANs / WANs
• eigrp router-id command
• Manually configure a Cisco router ID for EIGRP
• Router configuration mode of EIGRP
• Router ID is unique between the EIGRP routers
• When routes are redistributed into the Enhanced Interior Gateway Routing Protocol (EIGRP)