Well, I think we have said enough about EIGRP; we now know that it is based on autonomous systems, being either single or multiple. It is an enhanced routing protocol, due to the fact that it has both distance-vector and link state features. The maximum number of routers a packet can travel is 255 routers, but, by default, this is set to 100.
It uses a very sophisticated algorithm called diffused update algorithm, or DUAL, which makes lots of decisions based on metrics, such as the five K values of bandwidth, delay, load, reliability, and MTU. It also gets AD, or advertised distance, from its neighbor routers to calculate the distance to remote networks.
EIGRP also works with tables. The routing table, topology table, and neighbor table, all work together to make sure if a path to a destination network fails then the routing protocol will always have an alternate...