What is the default OSPF hello interval on Ethernet networks?

The default OSPF hello interval on Ethernet networks is indeed 10 seconds. This interval is important because it determines how frequently OSPF routers send hello packets to establish and maintain neighbor relationships. By sending hello packets at this interval, routers can quickly detect when a neighbor router is down, allowing for faster convergence of the OSPF routing topology.

In the OSPF protocol, hello packets are essential for neighbor discovery, and the consistency of the hello interval across OSPF routers is crucial for forming adjacencies. If the timers are not consistent between neighboring routers, they may declare each other as down, leading to potential routing issues.

Understanding the default timer configuration is critical for network professionals as it affects the performance and stability of an OSPF network. Adjusting these timers may be necessary in specific scenarios, such as high-speed WAN links, but the default setting of 10 seconds is standard for Ethernet, ensuring efficient neighbor discovery and upkeep of OSPF adjacencies.