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| 5.5 |  | Configuring EIGRP |
| 5.5.1 |  | Configuring EIGRP for IP networks |

Despite the complexity of DUAL, configuring EIGRP can be relatively simple. EIGRP configuration commands vary depending on the protocol that is to be routed. An example is IP, IPX, or AppleTalk. This section covers configuration commands for each of these routed protocols, in addition to special controls for IPX SAP.

Perform the following steps to configure EIGRP for IP:

1. Use the following to enable EIGRP and define the autonomous system.

> Router(config)#router eigrp autonomous-system-number

The autonomous-system-number is the number that identifies the autonomous system. It is used to indicate all routers that belong within the internetwork. This value must match all routers within the internetwork.

2. Indicate which networks belong to the EIGRP autonomous system on the local router.

> Router(config-router)#network network-number

The network-number determines which interfaces of the router are participating in EIGRP and which networks are advertised by the router.

The

network command configures only connected networks. For example, network 3.1.0.0, located on the far left of Figure , is not directly connected to Router A. Consequently, that network is not part of the configuration for Router A.

3. When configuring serial links using EIGRP it is important to configure the bandwidth setting on the interface. If the bandwidth setting is not changed for these interfaces EIGRP assumes the default bandwidth on the link instead of the true bandwidth. If the link is slower, the router may not be able to converge, routing updates might become lost, or suboptimal path selection may result.

> Router(config-if)#bandwidth kilobits

The value, kilobits, indicates the intended bandwidth in kilobits per second. For generic serial interfaces, such as PPP or HDLC, set the bandwidth to the line speed.

Cisco also recommends adding the following command to all EIGRP configurations:

> Router(config-router)#eigrp log-neighbor-changes

This command enables the logging of neighbor adjacency changes to monitor the stability of the routing system and to help detect problems.

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