Problem Description

Huawei NE40E router interfaces with Cisco C7304 router, set the same segment IP through subinterfaces, both subinterfaces transmit VLAN 1, and run the OSPF protocol, but the OSPF neighbors cannot establish FULL state.

Processing

Huawei NE40E router interfaces with Cisco C7304 router, sets the same segment IP through subinterfaces, and both subinterfaces pass through VLAN 1, and runs OSPF protocol, and the OSPF neighbors cannot establish FULL state.

Root cause

VLAN 1 data compatibility problem of different manufacturers.

Solution

This is also the actual project, when encountered and Cisco manufacturers equipment docking, such as the sub-interface found to run the OSPF protocol, the neighbor relationship can not be established, can be encapsulated non-VLAN1 data.

After the above troubleshooting, through the command display ospf peer brief view, OSPF neighbor relationship is normal, state is FULL state, the problem is solved.

Suggestions and Summary

Link sub-interface access between routers of different manufacturers, hardware and software configuration is normal, optional, it is recommended not to use VLAN1 pass-through encapsulation, you can consider using other VLAN encapsulation.