e-trunk bfd

Function

The e-trunk bfd command configures dynamic Bidirectional Forwarding Detection (BFD) session parameters in E-Trunk scenarios so that a dynamic BFD session is negotiated based on the configured parameters.

The undo e-trunk bfd command restores the default values of dynamic BFD session parameters.

The default local detection multiplier, minimum interval between receiving BFD packets, and minimum interval between sending BFD packets are 3, 10 ms, and 10 ms, respectively.

Format

e-trunk bfd { min-tx-interval mintx | min-rx-interval minrx | detect-multiplier multiplier } ^*

undo e-trunk bfd { min-tx-interval | min-rx-interval | detect-multiplier } ^*

Parameters

Parameter	Description	Value
min-tx-interval mintx	Specifies the minimum interval at which BFD packets are sent.	The value is an integer ranging from 3 to 20000, in milliseconds. The default value is 10.
min-rx-interval minrx	Specifies the minimum interval at which BFD packets are received.	The value is an integer ranging from 3 to 20000, in milliseconds. The default value is 10.
detect-multiplier multiplier	Specifies a local detection multiplier of a dynamic BFD session. You can specify different detection multipliers for both ends of a BFD session as required. Detection multipliers do not need to be negotiated during BFD session establishment.	The value is an integer ranging from 3 to 50.

Parameter

Description

Value

min-tx-interval mintx

Specifies the minimum interval at which BFD packets are sent.

The value is an integer ranging from 3 to 20000, in milliseconds. The default value is 10.

min-rx-interval minrx

Specifies the minimum interval at which BFD packets are received.

The value is an integer ranging from 3 to 20000, in milliseconds. The default value is 10.

detect-multiplier multiplier

Specifies a local detection multiplier of a dynamic BFD session.

You can specify different detection multipliers for both ends of a BFD session as required. Detection multipliers do not need to be negotiated during BFD session establishment.

The value is an integer ranging from 3 to 50.

Views

E-Trunk view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
etrunk	write

Usage Guidelines

Usage Scenario

You can set proper BFD session parameters as required.

If a device does not receive BFD packets from its peer before a specified detection period expires, the device considers the link faulty and sets the BFD session to Down. To reduce system resource consumption, the device automatically changes the local receive interval to a random value greater than 1000 ms after detecting that the BFD session goes Down. When the BFD session goes Up again, the device restores the configured receive interval.

Interval at which BFD packets are sent= max (Local minimum interval between sending BFD packets, Peer minimum interval between receiving BFD packets)
Interval at which BFD packets are received = max (Peer minimum interval between sending BFD packets, Local minimum interval between receiving BFD packets)
Detection period = Peer detection multiplier x max (Peer minimum interval between sending BFD packets, Local minimum interval between receiving BFD packets)

Prerequisites

A device has been enabled to create a dynamic BFD session using the e-trunk bfd enable command in the E-Trunk view.

Precautions

When dynamic BFD session parameters are configured in E-Trunk scenarios:

If you specify a large local detection multiplier, it takes a long period for the device to detect link faults through the BFD session. Traffic switches to the backup link only after the specified period elapses. Packet loss may occur within the period.
If you specify a large value for min-rx-interval or min-tx-interval, packet loss may occur.

Example

# Set the local detection multiplier, minimum interval between receiving BFD packets, and minimum interval between sending BFD packets to 8, 20 ms, and 40 ms, respectively.

<HUAWEI> system-view
[~HUAWEI] bfd
[*HUAWEI-bfd] quit
[*HUAWEI] e-trunk 1
[*HUAWEI-e-trunk-1] e-trunk bfd enable
[*HUAWEI-e-trunk-1] e-trunk bfd detect-multiplier 8 min-rx-interval 20 min-tx-interval 40

# Set the minimum interval at which BFD packets are sent to 30 ms.

<HUAWEI> system-view
[~HUAWEI] bfd
[*HUAWEI-bfd] quit
[*HUAWEI] e-trunk 1
[*HUAWEI-e-trunk-1] e-trunk bfd enable
[*HUAWEI-e-trunk-1] e-trunk bfd min-tx-interval 30

# Set the local detection multiplier to 6 for a dynamic BFD session.

<HUAWEI> system-view
[~HUAWEI] bfd
[*HUAWEI-bfd] quit
[*HUAWEI] e-trunk 1
[*HUAWEI-e-trunk-1] e-trunk bfd enable
[*HUAWEI-e-trunk-1] e-trunk bfd detect-multiplier 6

# Set the minimum interval at which BFD packets are received to 30 ms.

<HUAWEI> system-view
[~HUAWEI] bfd
[*HUAWEI-bfd] quit
[*HUAWEI] e-trunk 1
[*HUAWEI-e-trunk-1] e-trunk bfd enable
[*HUAWEI-e-trunk-1] e-trunk bfd min-rx-interval 30