What is the function of the OSPF 'Hello' packet?

The function of the OSPF 'Hello' packet is primarily to maintain the adjacency between OSPF routers. OSPF, which stands for Open Shortest Path First, relies on these Hello packets to discover and identify other OSPF-enabled devices on the same network segment. When OSPF routers exchange Hello packets, they negotiate the parameters of their communication, including hello and dead intervals, which are essential for establishing and maintaining their neighboring relationships.

These packets play a crucial role in maintaining the state of the adjacency between routers, ensuring that they stay aware of each other's presence and health. If a router does not receive Hello packets from a neighbor for a defined period (determined by the dead interval), it will assume that the neighbor is down and can remove it from the routing table, thus enhancing network reliability and maintaining accurate routing information.

While some of the other options focus on routing updates or table management, they do not directly address the primary role of Hello packets in building and maintaining OSPF adjacencies.