H3C Technologies H3C S12500 Series Switches - Manual (Page 147)

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Solution
1. Display OSPF neighbor information by using the display ospf peer command.
2. Display OSPF interface information by using the display ospf interface command.
3. Ping the neighbor router's IP address to check connectivity.
4. Check OSPF timers. The dead interval on an interface must be at least four times the hello interval.
5. On an NBMA network, use the peer ip-address command to manually specify the neighbor.
6. At least one connected interface must have a router priority higher than 0 on an NBMA or a
broadcast network.
Incorrect routing information
Symptom
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 belong to 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 attached are configured with the stub command. In an NSSA area, all
routers attached 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.