Verifying the OSPF Protocol

Purpose

After you have verified that the LSP is down, and the cause is not in the physical, datalink, or IP layer, verify the OSPF configuration. Check the routers in your network to ensure that the interfaces and the OSPF protocol are configured correctly, and that the neighbors are established.

Figure 17: MPLS Network Broken at the OSPF Protocol Layer

The crosses shown in Figure 17 indicate where the LSP is not working because of problems with the OSPF protocol configuration. The OSPF protocol is configured with a RID but without the loopback (lo0) interface, and traffic engineering is missing from the transit router (R3).

Steps To Take

1. Verify the LSP
2. Verify OSPF Interfaces
3. Verify OSPF Neighbors
4. Verify the OSPF Protocol Configuration
5. Take Appropriate Action
6. Verify the LSP Again