The isis lfa-backup command enables an IS-IS interface to participate in loop-free alternate (LFA) calculation so that the interface can be a candidate for a backup interface.
The undo isis lfa-backup command disables an IS-IS interface from participating in LFA calculation.
By default, an IS-IS interface can participate in LFA calculation.
Product |
Support |
|---|---|
S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S |
Supported |
S2720-EI, S5720I-SI, S5720-LI, S5735-L, S5735S-L, S5735S-L-M, S5720S-LI, S5720S-SI, S5720-SI, S5735-S, S5735S-S, S5735-S-I, S5730S-EI, S5730-SI, S6720-LI, S6720S-LI, S6720S-SI, and S6720-SI |
Not supported |
isis lfa-backup [ level-1 | level-2 | level-1-2 ]
undo isis lfa-backup [ level-1 | level-2 | level-1-2 ]
| Parameter | Description | Value |
|---|---|---|
| level-1 | Indicates that an interface can be a backup interface in Level-1 areas. | - |
| level-2 | Indicates that an interface can be a backup interface in Level-2 areas. | - |
| level-1-2 | Indicates that an interface can be a backup interface in both Level-1 and Level-2 areas. | - |
To facilitate traffic management and avoid the uncertainty in the traffic forwarding path in the case the primary link fails, run the undo isis lfa-backup command on some interfaces to disable them from participating in LFA calculation.
IS-IS has been enabled on the interface using the isis enable command.
# Disable VLANIF100 from becoming a backup interface for IS-IS Auto FRR.
<HUAWEI> system-view [HUAWEI] isis [HUAWEI-isis-1] network-entity 01.0000.0000.0001.00 [HUAWEI-isis-1] quit [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] isis enable 1 [HUAWEI-Vlanif100] undo isis lfa-backup
# Disable GE0/0/1 from becoming a backup interface for IS-IS Auto FRR.
<HUAWEI> system-view [HUAWEI] isis [HUAWEI-isis-1] network-entity 01.0000.0000.0001.00 [HUAWEI-isis-1] quit [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] undo portswitch [HUAWEI-GigabitEthernet0/0/1] isis enable 1 [HUAWEI-GigabitEthernet0/0/1] undo isis lfa-backup