Advanced IP Network Design (CCIE Professional Development)

Case Study: Troubleshooting EIGRP Neighbor Relationships

There are numerous reasons why EIGRP may have problems establishing neighbor relationships. In order to determine the source of the problem, the first thing to do is to add the command eigrp log-neighbor-changes under the router process in the configuration of every router. This will give you much more information about the cause of any neighbor problems.

This Case Study describes two common problems that cause EIGRP not to establish neighbors successfully. The first problem occurs when the primary addresses used by the routers trying to be neighbors do not belong to the same subnet. The second common problem occurs when the underlying media is failing to deliver either unicast or multicast ...