What Is BGP?
Border Gateway Protocol (BGP) is the Internet’s primary routing protocol. It has been described as the protocol that “makes the Internet work” because it plays such an important role in allowing traffic to move quickly and efficiently.
The original function of BGP was to carry internet reachability information between edge routers (it is sometimes described as a reachability protocol). It has since expanded to also carry routes for VPNs, IPv6, Multicast, and a range of other data. BGP provides network stability as it guarantees routers can rapidly adapt to send packets via a different connection if one Internet pathway goes down. It does this by exchanging routing information across the Internet, through the use of BGP-speaking routers and routing tables.