The OSPF protocol is often used in the networking. During the use of the OSPF protocol, the OSPF neighbor relationship cannot be established. Due to many reasons, the OSPF neighbor relationship fails to be established.
1.Router-ID Same
The two devices establish an OSPF neighbor relationship. When the Router-ID values of the two devices are the same, the device considers that the peer device sends packets and does not accept the OSPF neighbor relationship.
2. The area IDs are inconsistent.
If the interfaces connected to the two devices are in different areas, the OSPF neighbor relationship cannot be established.
3. The authentication is inconsistent.
If different OSPF authentication modes are configured on the interfaces of two devices, the OSPF neighbor relationship cannot be established because the authentication fails.
4. The masks are inconsistent (in the MA network).
The DR and BDR need to be selected on the MA network. When the masks are inconsistent, the DR and BDR cannot be selected. As a result, the OSPF neighbor relationship fails to be established.
5.hello and dead are inconsistent.
If the hello/dead time on the two devices is different, the OSPF neighbor relationship fails to be established.
6.silent-interface (silent port, not sent by the port)
After a port is configured with the silent port command, the port does not receive or transmit packets, and no packet is exchanged. As a result, the OSPF neighbor relationship cannot be established.
7.priority (on an MA network)
On the MA network, the DR and BDR need to be selected. When the priority of the device is 0, it indicates that all devices do not participate in the DR and BDR election. As a result, the OSPF forest creation fails.
8.network Inconsistent
When OSPF is configured, the interface address is advertised and OSPF is enabled. When two devices advertise different network segment addresses on the link, the OSPF neighbor relationship cannot be established.
The values of 9.MTU are inconsistent.
By default, MTU detection is disabled on Huawei devices. When Huawei devices connect to non-Huawei devices to establish OSPF, you must start MTU detection on both devices or disable MTU detection at the same time. Otherwise, OSPF neighbor relationships fail to be established.
