Which IP protocol number is assigned to OSPF?

Open Shortest Path First (OSPF) is a routing protocol used to facilitate the exchange of routing information within an autonomous system. Each protocol at the network layer of the Internet Protocol Suite is assigned a unique number, which identifies it to the IP protocol stack. OSPF is specifically assigned the protocol number 89.

This numerical assignment ensures that when OSPF packets are transmitted through a network, routers and devices can recognize and properly handle them using the corresponding OSPF processes. Understanding this assignment is essential for network professionals, as it aids in troubleshooting and configuring networks effectively. Recognizing OSPF's protocol number can also assist in learning how routing protocols interact within the broader context of IP networking.

Other numbers that are commonly associated with different protocols, such as 88 (used for EIGRP), 6 (used for TCP), and 17 (used for UDP), help delineate how various protocols function within network communications, but they are not relevant for OSPF.