What is the default dead interval for OSPF neighbors?

The default dead interval for OSPF (Open Shortest Path First) neighbors is indeed 40 seconds. The dead interval is an important timer in the OSPF protocol that indicates the time that must pass before a router considers a neighbor to be down if no hello packets have been received from that neighbor.

OSPF routers send hello packets at regular intervals to maintain neighbor relationships and keep track of the status of those neighbors. If a router fails to receive any hello packets from a neighbor within the dead interval period, it will assume that the neighbor is down and begin the process of recalculating the OSPF routing table accordingly.

This timer plays a crucial role in ensuring efficient network operations, allowing for quick identification of failed links while avoiding false positives from transient connectivity issues. Thus, a dead interval of 40 seconds is structured to balance responsiveness and stability in OSPF routing environments.