Why are routes in the OSPF routing table on an S series switch in the inactive state

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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.

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 cannot an OSPF route contained in the LSDB/LSA be queried in the routing table on an S series switch
Question: Why cannot an OSPF route contained in the LSDB/LSA be queried in the routing table? Answer: Perform the following operations on the S series switch to solve the problem. Check whether the IP address is valid. Check whether the forwarding address is known and reachable. Check whether the route aggregation or route import is correct. Check whether a different mask or IP address is used in P2P connection. Check whether the advertise route list is configured. Check whether the connection with the backbone area is proper. Check whether OSPF is enabled on the secondary IP address instead of the primary IP address.

Commands for checking OSPF routing table faults on S series switches
You can run the following commands on an S series switch supporting OSPF to check information about OSPF routing table faults: display ospf peer The command output displays information about an OSPF neighbor. display ospf routing The command output displays OSPF routing table entries. display ospf lsdb The command output displays information about an LSDB of OSPF.

Why cannot an OSPF route that exists in the LSDB be found in the routing table
Perform the following steps to solve this problem: Check whether the IP address is valid. Check whether the forwarding address is known and reachable. Check whether the routes are summarized or redistributed correctly. Check whether different masks or IP addresses are used in the Peer-to-peer (P2P) connection. Check whether route lists are advertised. Check whether the backbone area is disconnected. Check whether OSPF is enabled on the secondary address but not on the primary address. Parent topic: IP Routing

Why configure OSPF route tag on S series switches
For S series switches supporting OSPF, the OSPF router tag is applied to VPNs and prevents loops of Type 5 LSAs in CE dual-homing networking. If the tag of a received Type 5 LSA is the same as the router tag of OSPF on a PE, the PE neglects this LSA when calculating routes. When a CE is connected to two PEs, PE1 generates a Type 5 LSA based on the imported BGP route and sends the LSA to the CE, and the CE forwards the LSA to PE2. The OSPF route takes precedence over the BGP route, so PE2 replaces the BGP route with the OSPF route. As a result, a loop occurs. If the route tag is configured on a PE, when the PE receives an LSA with the same route tag as its own route tag, it neglects this LSA, avoiding loops. By default, the route tag is calculated using the BGP AS number. If BGP is not configured, the route tag is 0. In OSPF public network instances, router tags cannot be used to prevent loops but can be used as a filtering condition in a policy. When setting the router tag of ASE-LSAs and NSSA-LSAs, not the following: The route-tag command is used in the OSPF multi-instance scenario. The default tag command is used in the OSPF public network instance scenario. The import-route tag command can be used in either of the preceding scenarios.

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