Key Differences Between EIGRP and OSPF

EIGRP (Enhanced Interior Gateway Routing Protocol) and OSPF (Open Shortest Path First) are both interior gateway routing protocols used in networking. Here are some key differences between EIGRP and OSPF:

1. Algorithm: EIGRP uses a proprietary algorithm that calculates the shortest path to a destination, taking into account bandwidth, delay, load, and reliability. OSPF, on the other hand, uses the Dijkstra algorithm to calculate the shortest path based on cost.
2. Convergence: EIGRP has faster convergence compared to OSPF due to its DUAL (Diffusing Update Algorithm) mechanism, which allows for quick route recomputation. OSPF has a longer convergence time as it recalculates routes when topology changes occur.
3. Metric: EIGRP uses bandwidth and delay as its metric, while OSPF uses cost based on link speed. EIGRP's metric calculation is more flexible and supports various parameters for path selection.
4. Protocol Type: EIGRP is a distance vector protocol with some characteristics of link-state protocols, while OSPF is a pure link-state protocol that maintains a detailed view of the network topology.
5. Administrative Distance: EIGRP has a default administrative distance of 90 for internal routes and 170 for external routes, while OSPF has a default administrative distance of 110.

Understanding these key differences can help in choosing the appropriate routing protocol for a network's specific requirements.