This chapter describes how to configure Enhanced Interior Gateway Routing Protocol (E IGRP). For a complete description of the EIGRP commands listed in this chapter, refer to the “EIGRP Commands” chapter of the Network Protocols Command Reference, Part 1. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
Refer to the Network Protocols Configuration Guide, Part 2 for information on AppleTalk Enhanced IGRP or IPX Enhanced IGRP.
For protocol-independent features that work with EIGRP, see the chapter “Configuring IP Routing Protocol-Independent Features.
EIGRP is an enhanced version of IGRP developed by Cisco Systems, Inc. EIGRP uses the same distance vector algorithm and distance information as IGRP. However, the convergence properties and the operating efficiency of EIGRP have improved significantly over IGRP.
The convergence technology is based on research conducted at SRI International and employs an algorithm referred to as the Diffusing Update Algorithm (DUAL). This algorithm guarantees loop-free operation at every instant throughout a route computation and allows all devices involved in a topology change to synchronize at the same time. Routers that are not affected by topology changes are not involved in recomputations. The convergence time with DUAL rivals that of any other existing routing protocol.Read more…