Routing on the internet is actually performed between autonomous systems (ASes). Those autonomous systems need a way to determine how to send data to ASes that they are not directly connected with. To do this, the use the border gateway protocol, or BGP. By exchanging routing announcements using BGP routers located in each autonomous system can eventually build up a routing table allowing them to determine the best way to reach any other AS connected to the internet.

Credits: Talking: Geoffrey Challen (Assistant Professor, Computer Science and Engineering, University at Buffalo). Producing: Greg Bunyea (Undergraduate, Computer Science and Engineering, University at Buffalo).

Part of the https://www.internet-class.org online internet course. A blue Systems Research Group (https://blue.cse.buffalo.edu) production.