Explains how routers use various configurable policies to determine precisely which routes are accepted by the router or advertised to other routers. Once the role of a particular routing policy is established in a chapter, the actual syntax for implementing that routing policy is presented in the configuration languages of both Cisco and Juniper network routers. Goralski, who works for Juniper Networks, covers the routing information protocol (RIP), open shortest path first (ISPF), intermediate system (IS-IS), and the border gateway protocol (BGP).