BGP Short Overview

Here is my short overview of BGP from my studies today.

BGP

BGP is an exterior gateway protocol. We use BGP to route between AS's.

BGP runs on TCP port 179 for its operation.

BGP Features:

• Reliable updates
• Triggered updates
• Rich metrics (path attributes) for tuning
• Extremely scalable
• Neighbors not discovered they have to be manually configured.

BGP Peering and Route Advertisement

• The "neighbor remote-as" command is used for Internal BGP and External BGP peerings.
• eBGP are assumed to be directly connected, if not, you need to use the "ebgp-multihop" command.

• The "network" command is used to advertise prefixes; the prefix must be in the routing table (static route to null0 at least)