Which routing protocol is described as Cisco-originated, now open standard, using a composite metric and fast convergence?

Which routing protocol is described as Cisco-originated, now open standard, using a composite metric and fast convergence?

• A. BGP
• B. RIP
• C. OSPF
• D. EIGRP

Answer: (D)

EIGRP is designed around using a composite metric to choose the best path, rather than relying on a single factor like hop count. It can weigh several path characteristics—such as bandwidth, delay, and optional factors like reliability and load—to determine the most efficient route. This gives more accurate and scalable routing decisions in diverse networks. What makes it really fast is the Diffusing Update Algorithm, which provides rapid, loop-free convergence. EIGRP sends updates only when there’s a topology change, and it can identify feasible successors to immediately switch to if the primary route fails, avoiding full network rebuilds. Historically, this protocol originated with Cisco, but it’s now available as an open standard, which aligns with the description given. In contrast, other protocols mentioned are either not Cisco-originated or use different mechanisms: RIP relies on hop count, OSPF is a link-state protocol, and BGP is a path-vector exterior gateway protocol with a very different metric and convergence behavior.

EIGRP is designed around using a composite metric to choose the best path, rather than relying on a single factor like hop count. It can weigh several path characteristics—such as bandwidth, delay, and optional factors like reliability and load—to determine the most efficient route. This gives more accurate and scalable routing decisions in diverse networks.

What makes it really fast is the Diffusing Update Algorithm, which provides rapid, loop-free convergence. EIGRP sends updates only when there’s a topology change, and it can identify feasible successors to immediately switch to if the primary route fails, avoiding full network rebuilds.

Historically, this protocol originated with Cisco, but it’s now available as an open standard, which aligns with the description given. In contrast, other protocols mentioned are either not Cisco-originated or use different mechanisms: RIP relies on hop count, OSPF is a link-state protocol, and BGP is a path-vector exterior gateway protocol with a very different metric and convergence behavior.