Understanding BGP Routing and Troubleshooting Reachability Issues
Basic Overview :- BGP is a Path vector protocol. It uses TCP port no. 179 . BGP use path vector attributes such as AS path length, local preference, origin type, and other optional attributes to determine the best path to reach a specific network prefix. The AS path attribute helps prevent routing loops by specifying the sequence of ASNs (Autonomous System Numbers) through which the route has traversed. BGP is also known as “AS-by-AS routing protocol ”. In short, internet means network of network. When user try to access towards internet packet traverse through different AS. How it’s happened?? Let’s check. Illustration 1: PGCIL user wants to access cricbuzz website to see live cricket match score. How packet traverse from source to destination to access internet Via AS By AS is shown as below ...