Routing And Switching Questions
EIGRP (Enhanced Interior Gateway Routing Protocol) and OSPF (Open Shortest Path First) are both routing protocols used in computer networks, but they differ in several ways:
1. Protocol Type: EIGRP is a Cisco proprietary protocol, meaning it is only used in Cisco devices, while OSPF is an open standard protocol that can be used in devices from different vendors.
2. Metric Calculation: EIGRP uses a composite metric that takes into account bandwidth, delay, reliability, load, and MTU (Maximum Transmission Unit) to calculate the best path. OSPF, on the other hand, uses a cost-based metric that is based solely on the bandwidth of the link.
3. Convergence: EIGRP has faster convergence time compared to OSPF. EIGRP uses Diffusing Update Algorithm (DUAL) to quickly converge and adapt to network changes, while OSPF uses the Shortest Path First (SPF) algorithm, which may take longer to converge.
4. Scalability: OSPF is more scalable than EIGRP. OSPF divides the network into areas, which reduces the amount of routing information that needs to be exchanged between routers. EIGRP does not have this hierarchical structure, which can lead to scalability issues in larger networks.
5. Administrative Distance: EIGRP has a default administrative distance of 90, while OSPF has a default administrative distance of 110. Administrative distance is used to determine the trustworthiness of routing information from different sources, with lower values being more trusted.
6. VLSM Support: OSPF supports Variable Length Subnet Masking (VLSM), which allows for more efficient use of IP address space by using different subnet mask lengths within a network. EIGRP also supports VLSM.
Overall, the choice between EIGRP and OSPF depends on the specific network requirements, vendor preferences, and the level of scalability and convergence speed needed.