Cisco APIC Layer 3 Networking Configuration Guide, Release 6.2(x)

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Cisco APIC Layer 3 Networking Configuration Guide, Release 6.2(x)

Create an OSPF timers policy

Updated: April 17, 2026

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Creates an OSPF timers policy that defines interface metrics, administrative distance, ECMP, SPF scheduling, LSA processing, and LSA-limit behavior for a VRF.

Before you begin

Create the OSPFv2 interface profile. For instructions, see Create an OSPF interface profile .

OSPF timers control protocol-message processing and shortest path first (SPF) calculations. Associate the completed policy with a VRF.

Procedure

  1. From the menu bar, choose Tenants > tenant_name > Policies > Protocol > OSPF > OSPF Timers .

  2. In the Work pane, click Create OSPF Timers Policy.

  3. In the Name field, enter a policy name that contains 1 through 64 alphanumeric characters.

    Note

    You cannot change the name after you save the policy.

  4. In the Description field, enter a description that contains up to 128 alphanumeric characters.

  5. In the Bandwidth Reference field, enter the reference bandwidth that OSPF uses to calculate default interface metrics.

    The range is 1 through 40000. The default is 40000.

  6. In the Admin Distance Preference field, enter the administrative distance.

    The administrative distance determines route preference when multiple routing protocols provide routes to the same destination. The range is 1 through 255. The default is 110.

  7. In the Maximum ECMP field, enter the maximum number of equal-cost paths.

    The range is 1 through 16. The default is 8.

  8. In the Control Knobs field, select one or more OSPF controls.

    • Enable Name Lookup for Router IDs: Enables name lookup for router IDs.

    • Prefix Suppression: Prevents prefix advertisement.

  9. Select Graceful Restart Controls to enable OSPF graceful restart, also known as nonstop forwarding (NSF).

    Graceful restart keeps OSPF in the data-forwarding path during a process restart.

  10. In the Initial SPF Schedule Delay Interval (ms) field, enter the delay before the first SPF calculation.

    The range is 1 through 600000 ms. The default is 200 ms.

  11. In the Minimum Hold Time Between SPF Calculations (ms) field, enter the minimum interval between SPF calculations.

    After the initial calculation, each interval doubles until it reaches the maximum wait time. The range is 1 through 600000 ms. The default is 1000 ms.

  12. In the Maximum Wait Time Between SPF Calculations (ms) field, enter the maximum interval between SPF calculations.

    The range is 1 through 600000 ms. The default is 5000 ms.

  13. In the LSA Group Pacing Interval (seconds) field, enter the interval for grouping, refreshing, checksumming, and aging LSAs.

    The range is 1 through 1800 seconds. The default is 10 seconds. Decrease the interval for a large LSA database, and increase it for a small database.

  14. In the LSA Generation Throttle Start Wait Interval (ms) field, enter the initial LSA-generation throttle interval.

    The range is 0 through 5000 ms. The default is 0 ms.

  15. In the LSA Generation Throttle Hold Interval (ms) field, enter the incremental interval for calculating subsequent LSA-generation rate limits.

    The range is 50 through 30000 ms. The default is 5000 ms.

  16. In the LSA Generation Throttle Maximum Interval (ms) field, enter the maximum interval for calculating subsequent LSA-generation rate limits.

    The range is 50 through 30000 ms. The default is 5000 ms.

  17. In the Minimum Interval Between Arrival of an LSA (ms) field, enter the minimum interval for accepting another instance of the same LSA.

    An LSA instance has the same LSA ID, LSA type, and advertising-router ID. The software drops an instance that arrives before the interval expires. The range is 10 through 600000 ms. The default is 1000 ms.

  18. In the Maximum Number of Not Self-Generated LSAs field, enter the maximum number of LSAs that OSPF did not generate locally.

    The default is 20000.

  19. In the LSA Maximum Sleep Ignore Count Interval (ignore-time) field, enter the number of minutes that OSPF remains in the ignore state after exceeding the LSA limit.

  20. In the LSA Maximum Sleep Ignore Count (ignore-count) field, enter the maximum number of times that OSPF can enter the ignore state before manual recovery is required.

  21. In the LSA Sleep Count Reset Interval (reset-time) field, enter the number of minutes that OSPF must operate normally before resetting the ignore-state counter to 0.

  22. In the LSA Threshold (percentage) field, enter the warning threshold as a percentage of the maximum LSA count.

    The default is 75 percent.

  23. From the LSA Maximum Action field, select Log or Reject.

  24. Click Submit.

The OSPF timers policy is created in the tenant.

What to do next

To associate the policy with a VRF, choose Tenants > tenant_name > Networking > VRFs > VRF_name > Policy > OSPF Timers , and select the policy.

OSPF link-state database overload protection is a resource-protection mechanism that

  • monitors the number of nonself-generated link-state advertisements (LSAs) that an OSPF process receives,

  • limits excessive LSA processing to protect CPU and memory resources, and

  • uses configurable thresholds, actions, and ignore-state controls to manage overload conditions.

Overload behavior and recovery

The router compares the number of received nonself-generated LSAs with the configured limit. When the number exceeds the limit, the router generates a fault and can place the OSPF process in an ignore state to protect system resources.

To recover an OSPF process from a permanent ignore state, perform one of the following actions:

  • Disable and reenable the OSPF process in the L3Out.

  • Restart the OSPF process.

  • Reload the device.

Note

When LSA Maximum Action is set to Log, the OSPF process logs a fault after the limit is exceeded but does not change OSPF adjacencies.