Hello Samir
Sometimes it depends on the mismatch. For example, if you have broadcast on one end and non-broadcast on the other, the adjacency won’t form. If you have broadcast on one end and point to point on the other, an adjacency will form, but you will get a Syslog message like so:
*Dec 19 06:51:24.260: %OSPF-4-NET_TYPE_MISMATCH: Received Hello from 2.2.2.2 on GigabitEthernet0/1 indicating a potential
network type mismatch
But you’ll get that only once upon creation of the adjacency, and if you miss it you may be in trouble.
So for your question, I’m assuming you are referring to mismatches that will create an adjacency, assuming we missed that first syslog message.
Other than the show ip ospf neighbor some additional commands that can help you to troubleshoot such situations include:
- `sh ip ospf interface brief’: This command will show you the OSPF network type for each interface on the router. You can use this command on both ends of the link to see if they match.
debug ip ospf adj: This command will show you the OSPF adjacency process in real-time. If there’s a mismatch in network type, you will see an error message stating that the network types do not match.sh run | section router ospf: This command will display the OSPF configuration section of the running configuration. You can check to see if ‘network point-to-point’ or ‘network broadcast’ is configured under the OSPF process.
I hope this has been helpful!
Laz