By default, LFA FRR is disabled for OSPF.
4. Enable TI-LFA FRR for OSPF. fast-reroute ti-lfa [ per-prefix ] [ route-policy route-policy-name
| host ]
By default, TI-LFA FRR is disabled for OSPF.
Disabling an interface from participating in TI-LFA calculation
Disabling an IS-IS interface from participating in TI-LFA calculation
1. Enter system view. system-view
2. Enter the view of IS-IS interface. interface interface-type interface-number
3. Disable the interface from participating in TI-LFA calculation. isis fast-reroute ti-lfa disable [ level-1 | level-2 ]
By default, an IS-IS interface participates in TI-LFA calculation.
Disabling an OSPF interface from participating in TI-LFA calculation
1. Enter system view. system-view
2. Enter the view of OSPF interface. interface interface-type interface-number
3. Disable the interface from participating in TI-LFA calculation. ospf fast-reroute ti-lfa disable
By default, an OSPF interface participates in TI-LFA calculation.
Configuring microloop avoidance
About this task
The following microloop avoidance methods are available:
•
FRR microloop avoidance —Provides microloop avoidance after a network failure.
On a network deployed with TI-LFA FRR, when a node or link fails, traffic will be switched to the backup path calculated by TI-LFA. If devices on the backup path have not finished route convergence, a loop is formed between the source node (failed node or the previous node along the link) and a device on the backup path. The loop exists until the devices on the backup path finish route convergence.
To resolve this issue, FRR microloop avoidance first switches traffic to the backup path calculated by TI-LFA after the node or link failure. Then, the source node waits for the nodes on the backup path to finish route convergence before starting route convergence.
•
SR microloop avoidance —Provides microloop avoidance both after a network failure and after a failure recovery.
After a network failure occurs or recovers, route convergence occurs on relevant network devices. Because of non-simultaneous convergence on network devices, microloops might be formed. After you configure SR microloop avoidance, the devices will forward traffic along the specified path before route convergence is finished on all the relevant network devices.
Because the forwarding path is independent of route convergence, microloops are avoided.
To leave sufficient time for IGP to finish route convergence, set the SR microloop avoidance
RIB-update-delay timer. Before the timer expires, failure relevant devices will forward traffic
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along the specified path. After the timer expires, IGP route convergence should have finished and traffic will traverse along the IGP-calculated path.
Restrictions and guidelines
If you configure both FRR microloop avoidance and SR microloop avoidance, SR microloop avoidance takes effect.
Configuring FRR microloop avoidance for IS-IS
1. Enter system view. system-view
2. Enter IS-IS view.
isis process-id
3. Enter IS-IS IPv4 unicast address family view. address-family ipv4
4. Enable FRR microloop avoidance for IS-IS. fast-reroute microloop-avoidance enable [ level-1 | level-2 ]
By default, FRR microloop avoidance is disabled for IS-IS.
5. (Optional.) Set the FRR microloop avoidance RIB-update-delay time. fast-reroute microloop-avoidance rib-update-delay delay-time
[ level-1 | level-2 ]
By default, the FRR microloop avoidance RIB-update-delay time is 5000 ms.
Configuring FRR microloop avoidance for OSPF
1. Enter system view. system-view
2. Enter OSPF view.
ospf process-id
3. Enable FRR microloop avoidance for OSPF. fast-reroute microloop-avoidance enable
By default, FRR microloop avoidance is disabled for OSPF.
4. (Optional.) Set the FRR microloop avoidance RIB-update-delay time. fast-reroute microloop-avoidance rib-update-delay delay-time
By default, the FRR microloop avoidance RIB-update-delay time is 5000 ms.
Configuring SR microloop avoidance for IS-IS
1. Enter system view. system-view
2. Enter IS-IS view.
isis process-id
3. Enter IS-IS IPv4 unicast address family view. address-family ipv4
4. Enable SR microloop avoidance for IS-IS. segment-routing microloop-avoidance enable [ level-1 | level-2 ]
By default, SR microloop avoidance is disabled for IS-IS.
5. (Optional.) Set the SR microloop avoidance RIB-update-delay time.
segment-routing microloop-avoidance rib-update-delay delay-time
[ level-1 | level-2 ]
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