3Com MSR 50 Series Configuration Manual page 969

5 On an NBMA network, using the peer ip-address command to specify the
neighbor manually is required.
6 On an NBMA or a broadcast network, at least one connected interface must have
a router priority higher than 0.
Incorrect Routing Symptom
Information
OSPF cannot find routes to other areas.
Analysis
The backbone area must maintain connectivity to all other areas. If a router
connects to more than one area, at least one area must be connected to the
backbone. The backbone cannot be configured as a Stub area.
In a Stub area, all routers cannot receive external routes, and all interfaces
connected to the Stub area must be associated with the Stub area.
Solution
1 Use the display ospf peer command to display neighbors.
2 Use the display ospf interface command to display OSPF interface information.
3 Use the display ospf lsdb command to display the Link State Database to check
its integrity.
4 Display information about area configuration using the display
current-configuration configuration ospf command. If more than two areas
are configured, at least one area is connected to the backbone.
5 In a Stub area, all routers are configured with the stub command. In an NSSA
area, all interfaces are configured with the nssa command.
6 If a virtual link is configured, use the display ospf vlink command to check the
state of the virtual link.
Troubleshooting OSPF Configuration 969