Cisco Certified Network Associate (CCNA) 2025 – 400 Free Practice Questions to Pass the Exam

EIGRP, or Enhanced Interior Gateway Routing Protocol, employs the Diffusing Update Algorithm (DUAL) for determining the best path for routing. This algorithm is crucial because it allows EIGRP to effectively calculate the shortest and most efficient pathways in a dynamic network environment.

DUAL provides several advantages, including rapid convergence and loop-free routes through its sophisticated method of maintaining topology information and metrics. It keeps track of both the feasible successors and successors, which ensures that if the primary route fails, EIGRP can quickly switch to a backup route without causing a disruption in traffic.

The other options, while they represent different approaches used by various routing protocols, do not apply to EIGRP. The path vector algorithm is used by BGP, the link state algorithm is employed by OSPF, and the distance vector algorithm is a characteristic of protocols like RIP, which lack the advanced features and efficiencies found in EIGRP's DUAL approach.