This chapter provided an overview of the BGP4 path vector routing protocol that forms the glue that holds together today's Internet consisting of tens of thousands of autonomous systems and BGP nodes. BGP can appear as either IBGP or EBGP.

A detailed description of full-mesh IBGP, route reflectors, and confederation was provided. In contrast, EBGP and EBGP multihop provides signaling connectivity to neighbor autonomous systems. A significant portion of this chapter dealt with components such as route servers, looking glasses, and the IRR.

This chapter concluded the discussion of dynamic routing protocols as such. A discussion of BGP security and Multiprotocol BGP ended the chapter and thus the routing part of this book. The following chapters deal with traffic shaping, queuing, and tunnel issues.