You can configure GATED to use one or more of the following protocols: Protocol RFC Description Routing Information RFC RIP is a commonly used interior Protocol (RIP) 1058, protocol that selects the route Versions 1 and 2 RFC 1723 with the lowest metric (hop count) as the best route. Open Shortest Path RFC 1583 Another interior routing First (OSPF) Version protocol, OSPF is a link-state 2 protocol (shortest path first) and better suited than RIP foruse in complex networks with many routers. Exterior Gateway RFC 904 EGP exchanges reachability Protocol (EGP) information between autonomous systems. An autonomous system is usually defined as a set of routers under a single administration, using an interior gateway protocol and common metric to route packets. Autonomous systems use exterior routing protocols to route packets to other autonomous systems. Border Gateway RFCs Like EGP, BGP exchanges Protocol (BGP) 1163, reachability information 1267, between autonomous systems 1771 but supports nonhierarchical topologies. BGP uses path attributes to provide more information about each route. Path attributes can include, for example, administrative preferences based on political, organizational, or security considerations. Router Discovery RFC 1256 This protocol is used to inform hosts of the availability of hosts it can send packets to and to supplement a statically configured default router.