Why is an OSPF-enabled interface on an S series switch in different states

13

Question: Why is an OSPF-enabled interface in different states?
Answer: If a tunnel interface is created using the IP address of an OSPF-enabled loopback interface and the tunnel interface is Down, the interface is in different states. You can run the display ospf interface all command to check details about an OSPF interface.

[HUAWEI]display ospf interface all
OSPF Process 1 with Router ID 1.1.1.1
Interfaces
Area: 0.0.0.0 (MPLS TE not enabled)
Interface: 1.1.1.1 (LoopBack0)
Cost: 1 State: DR Type: Broadcast MTU: 1500
Priority: 1
Designated Router: 1.1.1.1
Backup Designated Router: 0.0.0.0
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1
Interface: 1.1.1.1 (Tunnel0/0/1)
Cost: 1562 State: Down Type: P2P MTU: 1500
Unnumbered
Timers: Hello 10 , Dead 40 , Poll 120 , Retransmit 5 , Transmit Delay 1

Other related questions:
Why is an OSPF route on an S series switch in the Invalid Adv state
Question: Why is an OSPF route in the Invalid Adv state? Answer: After you run the display ip routing-table x.x.x.x verbose command on an S series switch supporting OSPF to check information about a specified route, you may find that Invalid Adv is displayed in the State field. Possible causes are as follows: A route with a smaller preference value, for example, a directly connected route, exists. The route is filtered out based on a filter policy. A sham link is configured on the outbound interface.

Why are routes in the OSPF routing table on an S series switch in the inactive state
A policy that filters all OSPF routes may be configured in an OSPF process. As a result, all routes in the OSPF routing table are in the inactive state.

Why is the default OSPF cost of an interface on an S series switch incorrect
Question: Why is default OSPF cost value incorrect? For example, after OSPF is enabled on a device, the default OSPF cost value of an Ethernet interface is 7. Generally, the default OSPF cost value of an interface is 1. Answer: The default OSPF cost value of an interface on an S series switch supporting OSPF depends on the values of bandwidth and bandwidth-reference. The value of bandwidth-reference is configured in an OSPF process. Generally, the default bandwidth-reference value is used. In this case, if the default bandwidth value is 100 Mbit/s, the OSPF cost value is 1.

Differences between interface authentication and area authentication for OSPF on S series switches
Rules for OSPF authentication on S series switches supporting OSPF are as follows: If an interface is configured with authentication, the authentication method configured on the interface is used. If the authentication is set to null, the interface is not authenticated. If the interface is not configured with authentication (null does not indicate no configuration), area authentication is used. If the area is not configured with authentication either, no authentication is performed.

Why is an interface in Down state on a CE series switch
If the indicator of a connected interface on a CE series switch is off, the interface does not go Up. You can run the display interface command on the switch to view the interface status. Common causes: 1. The interface is manually shut down. 2.The cable or optical fiber is faulty. 3. The optical module is faulty. 4. The local and remote interfaces fail to negotiate parameters including the duplex mode and rate. Recommended solutions: 1. Check whether the interface has been manually shut down using the shutdown command. If so, run the undo shutdown command in the interface view to enable the interface. 2. Connect the interface to another interface, and replace the optical module, optical fiber, or cable on the interface to check whether the interface, optical module, or optical fiber/cable is faulty. If the fault persists, see section "Interface Troubleshooting" in the Troubleshooting - Hardware.

If you have more questions, you can seek help from following ways:
To iKnow To Live Chat
Scroll to top