BGP (Border Gateway Protocol) is a routing protocol used to exchange routing information between different autonomous systems (ASes) on the internet. It is the protocol that enables communication between different internet service providers (ISPs) and allows them to exchange traffic between their networks.
BGP works by exchanging routing information between routers that are connected to each other in different ASes. When a router learns about a new route, it shares that information with its neighbors, which then share it with their neighbors, and so on. This process continues until all routers in all connected ASes have learned about the new route.
BGP uses a variety of metrics and policies to determine the best path for traffic between different ASes. These include factors like network bandwidth, hop count, and administrative preferences.
BGP is a critical component of the internet infrastructure, allowing for efficient and reliable routing of traffic across the global network.