Unable To Learn A Complete Network Topology - H3C S5600 SERIES Operation Manual

OSPF parameters on the interconnected interfaces must be consistent.
Area IDs on the interconnected interfaces must be the same.
Network ID and subnet masks of the interconnected interfaces must be consistent. (P2P networks
and virtual link are excluded.)
The interconnected interfaces have the same type of network.
If the network type of the interface on the local router is NBMA, a neighbor must be specified by
using the peer command.
Solution
Perform the following procedure.
1) Use the display ip interface brief command to verify that the link layer works normally.
2) Use the ping command to check network layer connectivity.
3) Use the display ospf interface command to view the OSPF interface configuration.
4) If the network type of an interface is NBMA, use the display current-configuration configuration
ospf command to verify that a neighbor is specified for the router.
5) Use the display ospf brief command to check that the OSPF timers are consistent with those on
the neighbor and that the dead time of the neighbor is four times the Hello interval.
6) Use the display ospf peer command to view neighbors.

Unable to Learn a Complete Network Topology

Symptom
The router running OSPF is unable to learn a complete network topology.
Analysis
Perform the following procedure to make analyses:
1) If multiple areas are configured on the router, check that one is specified as the backbone area.
2) Check that the backbone area is fully meshed.
3) Check that the backbone area is not configured as a Stub area or NSSA area.
4) Check that no virtual links are configured for the backbone area.
5) For a Stub area, check that the Stub attributes are configured for all routers in the area.
6) For an NSSA area, check that the NSSA attributes are configured for all routers in the area.
7) Check that Stub or NSSA areas are not a transit area of any virtual link. Virtual links cannot pass
through a Stub or NSSA area.
Solution
Perform the following procedure:
1) Use the display ospf peer command to view the OSPF neighbor status.
2) Use the display ospf interface command to view the OSPF configuration on an interface.
3) Use the display ospf lsdb command to view the LSDB information.
4) Use the display current-configuration configuration ospf command to view area
configurations.
5) If a virtual link is configured, use the display ospf vlink command to check that the OSPF virtual
link is normal.
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