Hybrid Routing Protocols
Enhanced IGRP (EIGRP) is a hybrid routing protocol developed by Cisco. EIGRP makes decisions based on metric information it receives from neighbors, and it employs some of the mechanisms of link-state protocols. It establishes adjacencies with neighboring routers, sends only changes in its updates, and keeps a topology database of the network. EIGRP uses Diffusing Update Algorithm (DUAL) to achieve rapid convergence, conserve bandwidth, and support multiple network protocols.