The Internet is a huge network and is made up of many smaller networks. To learn about routes in other networks, each network has to run a routing protocol. While protocols such as EIGRP (Enhanced Interior Gateway Routing Protocol), OSPF (Open Shortest Path First), and RIP (Routing Information Protocol) work well for many networks, they do not scale to support the needs of a gigantic network like the Internet, nor do they provide the level of administrative separation required. So, BGP (Border Gateway Protocol) is used by ISP (Internet Service Provider) and large enterprises to advertise IP routes to one another.

In this chapter, we'll learn about BGP and its features when compared to other routing protocols. We will also learn the commands used in BGP and configure it in Cisco Packet Tracer.