In BGP, what type of information does an AS exchange?

In Border Gateway Protocol (BGP), the primary type of information exchanged between autonomous systems (AS) is routing information. BGP is designed to facilitate the exchange of reachability information among different networks on the internet, making it essential for managing how data packets are routed from one AS to another. Each AS shares information about which IP address prefixes it can reach and the associated paths to those prefixes. This enables ASes to make informed decisions about the best routes for traffic based on factors such as path length and policy.

The focus of BGP on routing information makes it a critical component of the internet's operations, allowing disparate networks to cooperate and optimize routing in a scalable manner. This exchange supports the establishment of accurate routing tables across diverse ASes, thereby ensuring efficient communication within the larger internet infrastructure.