BGP is basically what routes the internet. It handles the routing of traffic between ASs (autonomous systems - independent networks owned by companies, with the

BGP is basically what routes the internet. It handles the routing of traffic between ASs (autonomous systems - independent networks owned by companies, with their own sets of public IP ranges). BGP is super complex, and it takes a lot of experience to understand the intricacies involved. Also BGP peering configurations are generally confidential, so much of BGP (which again, is literally the core of the internet) happens in the dark. There have been academic studies to try mapping out BGP routes, and you can see the routes when you do a traceroute. Somehow it all manages to work, mostly :). If you want to play with BGP, download Quagga - its interface emulates the Cisco router interface. Documentation is poor but you can just reference Cisco docs.