min-tx-interval

Function

The min-tx-interval command sets the minimum interval for sending BFD packets.

The undo min-tx-interval command restores the default minimum interval for sending BFD packets.

By default, the minimum interval for sending BFD packets is 1000 ms.

Format

min-tx-interval interval

undo min-tx-interval

Parameters

Parameter	Description	Value
interval	Specifies the minimum interval for sending BFD packets.	The value is an integer that ranges from 100 to 1000, in milliseconds. After the set service-mode enhanced command is configured on the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, and S6720-HI, the value ranges from 3 to 1000. After the set service-mode enhanced-bfd command is configured on the S5732-H, S6730-H, S6730S-H, S6730-S, and S6730S-S, the value ranges from 3 to 1000.

Views

BFD session view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

The local detection multiplier determines the detection time of a BFD session.

Detection time = Received Detect Multi of the remote system x Max (Local RMRI/Received DMTI)

where

Detect Multi: local detection multiplier, which is set by using the detect-multiplier command
Required Min Rx Interval (RMRI): minimum interval for receiving BFD packets, which is set by using the min-rx-interval command
Desired Min Tx Interval (DMTI): minimum interval for sending BFD packets, which is set by using the min-tx-interval command

Precaution

You can increase or reduce the minimum interval for sending BFD packets based on actual networking. The minimum interval for sending BFD packets determines the detection time of a BFD session. On an unstable link, if the minimum interval for sending BFD packets is small, the BFD session may flap. You can increase the minimum interval for sending BFD packets. The default value is recommended. Do not randomly change the minimum interval for sending BFD packets.
If no BFD packet is received from the peer device within the detection time, the link is considered as faulty and the BFD session enters the Down state. To reduce the usage of system resources, when the BFD session is detected in Down state, the system adjusts the sending interval to a random value greater than 1000 ms. When the BFD session becomes Up, the configured interval is restored.
On the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S, when the minimum interval for sending BFD packets is smaller than 100 ms and the working mode of the switch is normal, the original BFD session needs to be deleted. Then set the working mode of the switch and reconfigure the BFD session.

Table 1 describes the mapping between configured and actual values of the BFD packet sending interval on the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S.

**Table 1** Mapping between configured and actual values of the BFD packet sending interval
Configured Value (x)	Actual Value
3 ms <= x < 10 ms	3.3 ms
10 ms <= x < 20 ms	10 ms
20 ms <= x < 50 ms	20 ms
50 ms <= x < 100 ms	50 ms
100 ms <= x < 300 ms	100 ms
300 ms <= x < 500 ms	300 ms
500 ms <= x < 1000 ms	500 ms
x = 1000 ms	1000 ms

Example

# Set the minimum interval for sending BFD packets to 500 ms.

<HUAWEI> system-view
[HUAWEI] bfd session
[HUAWEI-bfd-session-session] min-tx-interval 500