Note: When OSPF is configured and running over an NBMA network, do not issue the clear ip ospf neighbor command simultaneously on both ends of the OSPF link. Doing so brings the OSPF link down completely. In this event, you must do one of the following on both sides of the link to bring the link back up:

• Reconfigure the OSPF neighbors on the NBMA interface with the neighbor command.
• Issue the clear ip ospf database command to clear and reset the OSPF adjacencies.
• Issue the shutdown command followed by the no shutdown command on the interface.