Enhanced Interior Gateway Routing Protocol
Enhanced Interior Gateway Routing Protocol is a distance vector routing protocol, where a router shares information with neighboring routers about the network in an autonomous system and shares only the information that neighboring routers don’t have instead of the whole message. It is an enhanced version of Interior Gateway Routing Protocol, both of them uses the same distant vector technology and the distance information within them is not changed.
EIGRP is also called as dynamic routing protocol as it lets router to share information with other routers whose EIGRP is correctly configured, which in turn reduces the network administrator’s workload, who don’t have veto to change the routing table manually. As IGRP doesn’t hold up to the changed design of the internet protocol that supports classless IPv4 addresses, it has been replaced by EIGRP.
Enhanced Interior Gateway Routing Protocol is modified in such a way that it lessens the router’s workload and the amount of data that is to be transmitted between the routers. Other than internet protocol networks EIGRP can also be used for AppleTalk and Novell NetWare networks.
Features supported by EIGRP are :
• Has the ability to use different authentication passwords at different times.
• When a route is changed, it sends only topology changes instead of sending the complete routing table.
• Supports MD5 authentication between two routers
• Supports Classless Inter-Domain Routing
• Supports load balancing on parallel links between sites
• Backwards compatibility with the IGRP routing protocols
• Consumes less bandwidth
• Supports VLSM(super nets/subnets)
Basic components of EIGRP:
Neighbor Discovery/Recovery :
On a directly connected network , a router finds its neighbor on receiving the Hello packet. Now, a request message is sent to DUAL asking to update the new neighbor with full route. In return a response message of full route is sent by the neighbor. Each hello packet consists of hold time, nothing but the...