What is the default OSPF designated router (DR) priority?

The default OSPF designated router (DR) priority is typically set to 128. In OSPF (Open Shortest Path First), the DR and backup designated router (BDR) are elected on broadcast and non-broadcast multi-access networks to reduce the amount of routing protocol traffic. The priority value determines the likelihood of that router being elected as the DR. If a router has a higher priority compared to others on the same segment, it is more likely to become the designated router.

When the priority is not explicitly configured on a router, the default value of 128 is used. This ensures a level of predictability in how routers are treated on OSPF networks, as routers with default behavior will operate consistently across diverse OSPF implementations. A priority of 0 would indicate that the router cannot become a DR, and values higher than 128 would increase the router's chances, but since the default must be understood for most configurations, 128 is the key value. Understanding this default value is essential for network engineers as it directly influences OSPF operations on multi-access networks.