Topology Description: NE40－－S6500 (L3)－－S3528G (L2)
Phenomenon: OSPF protocol is enabled between NE40 and S6500. Neighbor relation can reach full state, but they cannot learn routing information of the peer.
1. disp cur co ospf on two devices and OSPF configuration of two devices are correct.
2. display ospf peer on two devices and opposite peer state reaches full state. It indicates that LSDB of two devices is synchronized. disp ospf lsdb and it is actually synchronized.
3. LSDB is complete, but it is not based on routing table. It is possible that SPF algorithm is problematic.
4. Compare configuration of two devices. Connected Ethernet interface of NE40 and S6500 configures command "ospf network-type p2p". Ethernet network type of S6500 uses default broadcast type.
5. Change network type of Ethernet interface of both sides as P2P and the problem is solved. They can learn routing information of the peer.
1. The configuration is problematic.
2. The device is problematic.
Change network type of Ethernet as P2P. When OSPF protocol is enabled, DR and BDR do not need electing. It can quichken the speed of route convergence. If the configuration is not detailed, when one port configures P2P network, another port reserves broadcast network. Such problem occurs: OSPF neighbor can reach full state and LSDB is synchronized. But routing table cannot be computed (There is margin of LSDB. Correct SPT cannot be built and SPF algorithm cannot calculate correct route. Display OSPF brief and "SPF Computation Count: 0").