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| 5.2 |  | EIGRP Features |
| 5.2.2 |  | Neighbor discovery and recovery |

Remember that simple distance vector routers do not establish any relationship with their neighbors. RIP and IGRP routers merely broadcast or multicast updates on configured interfaces. In contrast, EIGRP routers actively establish relationships with their neighbors, much the same way that OSPF routers do.

EIGRP routers establish adjacencies with neighbor routers by using small hello packets. - Hellos are sent by default every five seconds. An EIGRP router assumes that as long as it is receiving hello packets from known neighbors, those neighbors (and their routes) remain viable. By forming adjacencies, EIGRP routers do the following:

- Dynamically learn of new routes that join their network
- Identify routers that become either unreachable or inoperable
- Rediscover routers that had previously been unreachable

| Interactive Media Activity Drag and Drop: EIGRP Operation Upon completion of this activity, the student will be able to identify the four key steps of EIGRP operation.