How many types of BGP sessions are there?

BGP, or Border Gateway Protocol, utilizes two main types of sessions for establishing communication between different autonomous systems. These sessions are crucial for the exchange of routing information across the internet.

The first type is an eBGP (External BGP) session, which occurs between routers that belong to different autonomous systems. eBGP is responsible for exchanging routing information among these autonomous systems, which is essential for inter-domain routing on the internet.

The second type is an iBGP (Internal BGP) session, which is used for communication between routers within the same autonomous system. iBGP helps in disseminating the routing information received from eBGP peers to other iBGP peers in the same autonomous system, ensuring that all routers within the AS have consistent routing tables.

These two types of BGP sessions work together to facilitate robust and scalable routing on the network, allowing for efficient handling of the diverse paths traffic can take across the internet.