5. Internal routing protocols

Internal routing protocols are designed to facilitate the management of an autonomous system by automating the construction of routing tables as far as possible. Routers exchange information about their view of the network via the routing protocol. Several internal routing protocols have been standardized:

• the simplest is RIP (routing information protocol ). It requires very little configuration but is only effective on small networks;

• The OSPF (open shortest path first) protocol and its ISO equivalent IS-IS (intermediate system to intermediate system) are considerably more complex, but are better suited to large networks such as operator networks;

• Finally, equipment manufacturer Cisco also offers proprietary IGRP and EIGRP procotoles.