Border Gateway Protocol

• Exterior gateway protocol
• "3-napkins protocol"
• Popular standard
• BGP uses a path vector protocol approach
  • It maintains the path information that gets updated dynamically as it exchanges routing information with other BGP routers across different autonomous systems.
  • This path vector is crucial for BGP to determine the best routes for data transfer across diverse, interconnected networks.
• Selects the best path primarily based on the length of the AS-path, which is the number of autonomous systems a route must pass through. A shorter AS-path is preferred.