Troubleshooting guide

BSR Troubleshooting Guide
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4. Use the debug ip ospf adj command in Privileged EXEC mode. Check the output
for mismatched values, as shown in the following example:
RDN#debug ip ospf adj
5. If mismatches are indicated in the debug output, try to resolve the mismatch.
6. Ensure that all routers in an area have the same area ID and authentication type,
and are configured as stub routers.
Mismatched IP MTU
This section describes what to do if the OSPF router rejects packets with a Maximum
Transmission Unit (MTU) size that exceeds the configured IP MTU of the
neighboring or adjacent OSPF interface.
Follow these steps to align IP MTU sizes between OSPF routers:
1. To determine the mismatched IP MTU size problem with the adjacent OSPF
router, use the debug ip ospf adj command in Privileged EXEC mode, as shown
in the following example:
RDN#debug ip ospf adj
2. Look in the debug ip ospf adj command output for a message similar to the
following example, which identifies that the neighboring OSPF router has a
larger MTU than the local OSPF router:
OSPF: Nbr 102.2.2.2 has larger interface MTU
3. To get the MTU value for the local OSPF router, use the show ip interface
command in Privileged EXEC mode, as shown in the following example:
RDN#show ip interface