EIGRP is a distance-vector protocol that can be extremely easy to implement in small to medium networks, yet can be designed to manage large-scale complex internetworks with many of the same advantages of more complex link-state protocols. Its proprietary nature, belonging exclusively to Cisco, means that improvements can continuously flow without the impedance of standards bodies. What is the joke? A camel is a horse designed by committee.

The underlying complexity of the protocol needs very careful consideration, but also allows an administrator to trust that the network is stable and robust and easily recovers from many abusive situations. Implementing a diffused computation method of best-path selection and the Hello Protocol to eliminate the need for periodic updates allows EIGRP to be implemented in environments where bandwidth is at a premium and yet remain fully converged for long periods of time. The resulting loop-free topology and alternate-path redundancy greatly reduces the demand on an administrator s time.

As you have seen, EIGRP is by no means a small protocol. With the ability to support VLSM and hierarchical summary addressing, the efficiency of the protocol is limited more by the administrator s ability than by its own design. Planning your network growth and redundancy will pay heavy dividends in the long run.