This chapter covers the following subjects:
First released in IOS 9.21, Enhanced Interior Gateway Routing protocol (EIGRP) is, as the name says, an enhancement of the Cisco Interior Gateway Routing Protocol (IGRP). The name is apt because unlike RIPv2, EIGRP is far more than the same protocol with some added extensions. Like IGRP, EIGRP is a distance vector protocol and uses the same composite metrics as IGRP uses. Beyond that, there are few similarities. IGRP was discontinued as of IOS releases 12.2(13)T and 12.2(Rls4)S. Although innovative in its time, modern network operators who desire more capability than RIP provides move to EIGRP or OSPF, not the moderately more capable IGRP. However, to understand EIGRP, it is useful to first examine the protocol from which it evolved. |