Which routing protocol is widely used by Internet service providers to maintain huge routing tables and efficiently process Internet traffic?

Which routing protocol is widely used by Internet service providers to maintain huge routing tables and efficiently process Internet traffic?

• A. Routing Information Protocol (RIP)
• B. Open Shortest Path First (OSPF)
• C. Enhanced Interior Gateway Routing Protocol (EIGRP)
• D. Border Gateway Protocol (BGP)

Answer: (D)

Routing between different networks on the Internet is built for scale and policy control, allowing many networks to share reachability information without overwhelming routers. Border Gateway Protocol is the protocol that handles this inter-domain routing. It operates as a path-vector protocol that uses attributes like the AS path to select best routes across thousands of networks, enabling ISPs to maintain huge routing tables and apply policies for traffic engineering and failover. It runs over TCP, which provides reliable delivery, and supports features such as route aggregation and filtering to keep the global routing state manageable. In contrast, RIP is limited by hop counts and doesn’t scale to Internet size, while OSPF and EIGRP are designed mainly for interior routing within an organization. That scalability and policy-driven control is why BGP is widely used by Internet service providers to manage Internet traffic.

Routing between different networks on the Internet is built for scale and policy control, allowing many networks to share reachability information without overwhelming routers. Border Gateway Protocol is the protocol that handles this inter-domain routing. It operates as a path-vector protocol that uses attributes like the AS path to select best routes across thousands of networks, enabling ISPs to maintain huge routing tables and apply policies for traffic engineering and failover. It runs over TCP, which provides reliable delivery, and supports features such as route aggregation and filtering to keep the global routing state manageable. In contrast, RIP is limited by hop counts and doesn’t scale to Internet size, while OSPF and EIGRP are designed mainly for interior routing within an organization. That scalability and policy-driven control is why BGP is widely used by Internet service providers to manage Internet traffic.