What is the default maximum number of equal-cost OSPF routes that may be added to the routing table?

The default maximum number of equal-cost OSPF (Open Shortest Path First) routes that can be added to the routing table is indeed 4. This means that when OSPF discovers multiple routes to the same destination that have equal cost, it will install up to 4 of those routes into the routing table for load balancing purposes. By using multiple equal-cost paths, OSPF can improve network performance and reliability by distributing traffic across several routes.

When the number of equal-cost paths exceeds this default limit, OSPF will not add any further routes into the routing table even if they exist, which is why configuring the maximum number of equal-cost routes is an important consideration for network design. If more than four equal-cost routes are available, the router will choose the best four based on the metrics defined and discard the rest for routing decisions.

In practical terms, this configuration allows for efficient bandwidth usage and redundancy in path selection. Adjusting this number can either enhance or limit the routing capabilities based on network requirements and design strategies.