Troubleshooting IP Routing Protocols (CCIE Professional Development Series)

When OSPF forms an adjacency , it floods all the link-state update packets to its neighbors. Sometimes, the flooding process takes a lot of time, depending upon the router resources. When a router's CPU gets too busy when flooding using the most of the router's resources, CPUHOG messages appear in the log.

The CPUHOG messages usually appear in two significant stages:

• Neighbor formation process

• LSA refresh process

This section discusses the possible solutions for these two instances of SPF:

• CPUHOG messages during adjacency formation

• CPUHOG messages during LSA refresh period