(also Border Gateway Protocol)
BGP, or Border Gateway Protocol, is a standardized exterior gateway protocol. It manages packet routing across the internet through the exchange of routing and reachability information among edge routers. BGP enables autonomous systems (ASes), which are large collections of IP networks and routers under the control of a single organization, to exchange routing information for the purpose of ensuring reliable and efficient data transmission across the internet.
BGP operates by establishing connections, called sessions, between neighboring routers, which then exchange routing information. The protocol is crucial for maintaining internet stability and preventing routing loops, ensuring that data packets reach their intended destination through the most efficient path.
BGP compared to other routing protocols
BGP is different from interior gateway protocols like OSPF (Open Shortest Path First) and EIGRP (Enhanced Interior Gateway Routing Protocol), which are used within an AS. While interior gateway protocols focus on finding the shortest path within an AS, BGP focuses on policy-based routing, allowing administrators to apply routing policies based on various attributes like AS path, community, or local preference.
Pros and cons of BGP
- Highly scalable and suitable for large networks.
- Policy-based routing offers granular control over traffic paths.
- A stable and proven protocol used by the global internet.
- Complex configuration and management.
- Slow convergence time compared to interior gateway protocols.
- Vulnerable to route leaks and hijacks if not properly secured.