What is the default OSPF Dead timer on Ethernet connections?

The default OSPF Dead timer on Ethernet connections is 40 seconds. The Dead timer is an important component of the Open Shortest Path First (OSPF) protocol, which helps to determine the interval after which a neighbor is considered down if no Hello packets are received. When the router does not receive Hello packets within the Dead timer period, it will remove that neighbor from its neighbor table, which helps maintain an accurate and efficient routing table.

In OSPF, the Hello interval is set to 10 seconds by default, which means that routers send Hello packets every 10 seconds to discover and maintain neighbor relationships. The Dead timer, being four times the Hello interval, ensures that the network can handle potential packet loss and delays without losing neighbor relationships prematurely. This design ensures stability in OSPF by allowing enough time for network fluctuations before declaring a neighbor unreachable. Consequently, for Ethernet connections, setting the Dead timer to 40 seconds provides a reliable mechanism for OSPF to monitor its neighbors while adapting to the dynamics of network traffic.