Disabling Routing Loop Detection for Routes Imported to OSPF
Usage Scenario
When an OSPF process imports routes, routing loops may occur. Routing loop detection can help prevent such routing loops. When a device detects that it imports a route advertised by itself, it sends this route with a large cost to other devices. After learning the route, these devices preferentially select other paths, thereby preventing routing loops. By default, OSPF routing loop detection is enabled.
OSPF uses Opaque LSAs to implement routing loop detection for imported routes. Therefore, the Opaque LSA capability must be enabled for this function. By default, the Opaque LSA capability is enabled on a device. If the Opaque LSA capability is disabled on the device using the opaque-capability disable command, you need to run the opaque-capability enable command to enable the Opaque LSA capability.
Procedure
- Run system-view
The system view is displayed.
- (Optional) Run clear route loop-detect ospf alarm-state The routing loop detection alarm state exits, and related alarms are cleared. If the device detects an OSPF routing loop, it reports an alarm. Because the device cannot automatically detect whether a routing loop is eliminated, you need to run this command to manually clear the OSPF routing loop alarm after the routing loop is eliminated. This prevents the device from advertising a large cost for imported routes in this case.
- Run route loop-detect ospf disable
Routing loop detection is disabled for routes imported to OSPF.
To reduce the impact of routing loops on services, you are advised to keep routing loop detection enabled for routes imported to OSPF.
- Run commit
The configuration is committed.