Describe the Enhanced Interior Gateway Routing Protocol (EIGRP).

What will be an ideal response?

Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco proprietary protocol designed to overcome the limitations found in IGRP. Although it is often described as a hybrid protocol containing the features of both distance-vector and link-state protocols, EIGRP is still a distance-vector routing protocol at its core, albeit an advanced one. EIGRP is classless, whereas RIPv1 and IGRP are classful. Therefore, EIGRP can support VLSM and complex internetworks. EIGRP can also route IP, IPX, and AppleTalk. Protocol Dependent Modules (PDMs) allow EIGRP to carry these multiple routed protocols within their own native packet formats. Finally, EIGRP uses nonperiodic, partial, and bounded routing table updates. So, EIGRP does send route information to directly connected neighbors, but not on a periodic basis. Instead, updates are only sent when changes occur to the network. Also, the updates do not include the entire routing table; they are partial, meaning that only routes that have changed are sent. Additionally, the updates are sent only to the routers that need to learn them, not to all directly connected routers. These updates are therefore considered bounded. Finally, because network security is paramount in today's world, EIGRP, like RIPv2, supports authentication of routing peers.