Interconnect Cisco Devices with OSPF Vlink

Hello,

The interconnection can be successful.

Cisco's feature: The virtual link is considered as a demand circuit. Therefore, Hello packets are sent only when a connection is established, and Hello packets are not sent after the connection is established.The LSA transmitted on the demand circuit is set to the DNA(DoNotAge) bit to suppress the LSA refresh function, indicating that the LSA is never aged.

Huawei feature: By default, Huawei devices do not consider virtual links as on-demand links. 

Interconnection process: When a Cisco device is connected to a Huawei device, the Huawei device does not process the virtual link as an on-demand link. The DC bit in the option field of the packet sent by the Huawei device is not set, so the on-demand link cannot be established. In this case, the Cisco device does not process the virtual link as an on-demand link (DNA in the LSA is not set). Instead, the Cisco device periodically sends Hello messages in unicast mode within 10s. The OSPF Vlink is successfully established.