Before fine tuning EIGRP features, start with a basic implementation of EIGRP.

Figure 1 shows the network topology used for this chapter.

Figures 2, 3, and 4 show the IPv4 interface configurations and the EIGRP implementations on R1, R2, and R3, respectively.

The types of serial interfaces and their associated bandwidths may not necessarily reflect the more common types of connections found in networks today. The bandwidths of the serial links used in this topology help explain the calculation of the routing protocol metrics and the process of best path selection.

Notice that the bandwidth commands on the serial interfaces were used to modify the default bandwidth of 1,544 kb/s.

In this chapter, the ISP router is used as the routing domain’s gateway to the Internet. All three routers are running Cisco IOS, Release 15.2.