EIGRP

EIGRP (Enhanced Interior Gateway Routing Protocol) is an advanced variation of distance vector routing protocol. It contains optimization that minimizes levels of routing instability that occur after topology along with the processing power and bandwidth used in a router. EIGRP supports many older routing protocols. In this scenario, a router running these processes can automatically redistribute information in between both protocols. Many of the EIGRP routing optimizations are based on the DUAL (Diffusing Update Algorithm). DUAL helps to ensure an operation free of loops and acts as a mechanism that provides speedy convergence. EIGRP gathers routing information from these three tables: the neighbor table, the topology table and the routing table. Unlike several other distance vector routing protocols, it does not require that routes are periodically dumped to maintain it’s topology. It enables routing information to be exchanged once as the router startups. Even then, information is only exchanged after changes are sent.