isis bfd
Function
The isis bfd command sets values of BFD session parameters on a specified IS-IS interface.
The undo isis bfd command restores the default values of BFD session parameters on a specified IS-IS interface.
By default, BFD session parameters use default values.
Only the 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 support this command.
Format
isis bfd { min-rx-interval receive-interval | min-tx-interval transmit-interval | detect-multiplier multiplier-value | frr-binding } *
undo isis bfd { min-rx-interval [ receive-interval ] | min-tx-interval [ transmit-interval ] | detect-multiplier [ multiplier-value ] | frr-binding } *
Parameters
| Parameter | Description | Value |
|---|---|---|
| min-rx-interval receive-interval | Specifies the minimum interval for receiving BFD packets from the peer end. | The value is an integer that ranges from 100 to 1000, in milliseconds.
|
| min-tx-interval transmit-interval | Specifies the minimum interval for transmitting BFD packets to the peer end. | The value is an integer that ranges from 100 to 1000, in milliseconds.
|
| detect-multiplier multiplier-value | Specifies the local detection multiplier. | The value is an integer that ranges from 3 to 50. The default value is 3. |
| frr-binding | Binds the BFD session status to IS-IS Auto FRR. When BFD detects the link fault on an interface, the BFD session goes Down, triggering FRR on the interface. After that, the traffic is switched from the faulty link to the backup link, which protects the traffic. | - |
Usage Guidelines
BFD can quickly detect faults on links. Configure proper parameters based on the actual network situation to improve the IS-IS convergence speed when network faults occur. You can use the isis bfd command to change BFD session parameters such as the minimum interval for sending BFD packets, minimum interval for receiving BFD packets, and local detection multiplier.
In an IS-IS process, after IS-IS establishes a BFD session, the value of receive-interval is obtained after the negotiation of the local min-rx-interval value and the remote min-tx-interval value. If no BFD packet is received from the peer end within the specified period (receive-interval x multiplier-value), the neighbor is considered Down.
Negotiation principle: Actual interval for the local device to receive BFD packets = MAX {local min-rx-interval value, remote min-tx-interval value}
PrerequisitesBFD has been enabled globally. In the interface view, IS-IS has been enabled and BFD has been enabled on the interface using the isis bfd enable command.
PrecautionsThe BFD priority of the interface is higher than that of the process. If BFD of the interface is enabled, the BFD session is set up based on the BFD parameters on the interface.
Example
# Enable BFD on VLANIF100 and set the minimum receive interval to 600 ms and local detection multiplier to 4.
<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] isis bfd enable [HUAWEI-Vlanif100] isis bfd min-rx-interval 600 detect-multiplier 4
# Enable BFD on GE0/0/1 and set the minimum receive interval to 600 ms and local detection multiplier to 4.
<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] isis bfd enable [HUAWEI-GigabitEthernet0/0/1] isis bfd min-rx-interval 600 detect-multiplier 4