Introduction to BGP

You might be aware that the Internet is often defined as a 'network of networks', interconnected with each other—but how exactly do your packets of data get routed from point A to point B across the planet as efficiently as possible?

The answer is a protocol called BGP, which is used by Internet routers to communicate with each other and work out the most efficient path to get your data from one computer to another, hop-to-hop.

When two independent networks, such as those run by ISPs (known as Autonomous Systems, or AS-es) want to send traffic to each other (without relying on some form of upstream transit provider) they establish what's known as peering sessions between their routers, and to do this they use the BGP protocol.