BGP peer
also: BGP neighbor, BGP router, BGP speaker
A BGP peer is another router that runs the Border Gateway Protocol and exchanges routing information with your router through a direct TCP connection.
A BGP peer is a router or network device configured to establish a BGP (Border Gateway Protocol) session with another router. BGP peers exchange routing advertisements and network reachability information to enable intelligent inter-domain routing across the internet.
BGP peers connect via TCP port 179 and form a peering relationship that can be either external (between different Autonomous Systems, or ASes) or internal (within the same AS). For example, an ISP router might peer with a customer's border router to advertise the customer's IP prefixes to the internet.
Each BGP peer maintains a session where they send UPDATE messages containing routing information, allowing both routers to learn about reachable networks and make forwarding decisions based on policies like AS path length, preferences, and community tags.