EIGRP vs OSPF: Key Differences, Pros & Cons
EIGRP (Enhanced Interior Gateway Routing Protocol) is Cisco’s proprietary, distance-vector-plus protocol that uses a composite metric to choose the fastest loop-free path. OSPF (Open Shortest Path First) is an open-standard, link-state protocol that builds a complete map of the network and recalculates shortest paths with Dijkstra’s SPF algorithm.
Network engineers often confuse the two because both run inside an enterprise, support VLSM, and advertise routes. Yet OSPF shows up in multivendor labs while EIGRP is the “Cisco-only” default in CCNA courses—so people pick the wrong acronym when drawing diagrams or troubleshooting tickets.
Key Differences
EIGRP uses DUAL for rapid convergence, keeps a feasible successor for backup, and speaks RTP between neighbors. OSPF floods LSAs, elects DR/BDR on broadcast segments, and recalculates the LSDB on every change. One favors simplicity and speed; the other trades CPU cycles for universal compatibility.
Which One Should You Choose?
Pick EIGRP if your network is all-Cisco, you want zero-touch failover, and licensing is no issue. Choose OSPF when you mix vendors, need granular area design, or face strict open-standard policies. In greenfield SD-WAN, both may lose to BGP anyway.
Can I redistribute between EIGRP and OSPF?
Yes, use route-maps and set metrics carefully to avoid loops.
Does EIGRP still need auto-summary?
No, modern IOS disables it; always verify with show run.