Miscellaneous OSPF Configuration Settings
These last few topics in the chapter discuss a few unrelated and optional OSPF configuration settings, namely how to make a router interface passive for OSPF, and how to originate and flood a default route using OSPF.
OSPF Passive Interfaces
Once OSPF has been enabled on an interface, the router tries to discover neighboring OSPF routers and form a neighbor relationship. To do so, the router sends OSPF Hello messages on a regular time interval (called the Hello interval). The router also listens for incoming Hello messages from potential neighbors.
Sometimes, a router does not need ...