OSPF vs EIGRP: The Complete Comparison
Both are powerful interior routing protocols, but they work differently: OSPF is a standards-based link-state protocol (every router builds a full map), while EIGRP is Cisco's advanced distance-vector protocol (fast convergence via precomputed backups). The choice often comes down to multi-vendor needs versus Cisco-only speed.
Side by side
| Factor | OSPF | EIGRP |
|---|---|---|
| Type | Link-state | Advanced distance-vector |
| Standard | Open (multi-vendor) | Cisco (now largely open) |
| Metric | Cost (bandwidth-based) | Bandwidth + delay (composite) |
| Convergence | Fast (SPF recalculation) | Very fast (feasible successors) |
| Admin distance | 110 | 90 (internal) |
| Design | Requires areas at scale | Flatter, simpler design |
The details that matter
OSPF shines in multi-vendor environments and scales through a hierarchical area design — every router computes the shortest-path tree with Dijkstra's algorithm. EIGRP converges even faster thanks to feasible successors (precomputed loop-free backups via DUAL) and is simpler to design, but was historically Cisco-only. In interviews: OSPF for standards and large hierarchical networks; EIGRP for fast convergence in a Cisco shop. Both are CCNP ENARSI topics — see OSPF and EIGRP guides.
Frequently asked questions
What is the main difference between OSPF and EIGRP?
OSPF is a standards-based link-state protocol where every router builds a full topology map; EIGRP is Cisco's advanced distance-vector protocol using precomputed backup routes for fast convergence.
Which converges faster, OSPF or EIGRP?
EIGRP often converges faster thanks to feasible successors — precomputed loop-free backups that install instantly when the primary fails.
Is EIGRP still Cisco-only?
EIGRP was Cisco-proprietary but has been released as an open standard; in practice it's still used mainly in Cisco environments.
Related articles
Want hands-on training?
Learn this on real Cisco lab devices with placement support at Attila Technologies, Ahmedabad.