OSPF Troubleshooting

Troubleshooting OSPF involves checking neighbor adjacencies, LSA database consistency, and routing table entries. Here are some common issues and commands.

Common Issues:

  • Neighbor Adjacency Issues: Mismatched Hello/Dead timers, network types, authentication, area IDs, or subnet masks.
  • LSDB Mismatches: Indicates issues with LSA flooding or database synchronization.
  • Routing Inconsistencies: Incorrect route calculations or missing routes.

Useful Commands:

  • show ip ospf neighbor: Verifies OSPF neighbor adjacencies and states.
  • show ip ospf database: Displays the OSPF link-state database.
  • show ip ospf interface [interface-type interface-number]: Shows OSPF interface parameters.
  • show ip protocols: Displays routing protocol parameters.
  • clear ip ospf process: Resets the OSPF process (use with caution).