e-trunk track bfd-session

Function

The e-trunk track bfd-session command binds a BFD session to an E-Trunk.

The undo e-trunk track bfd-session command unbinds a BFD session from an E-Trunk.

By default, no BFD session is bound to an E-Trunk.

Only the S5720-EI, S5720-HI, S5720I-SI, S5720S-SI, S5720-SI, S5735-S, S5735S-S, S5735-S-I, S5730-HI, S5730S-EI, S5730-SI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-EI, S6720-HI, S6720S-EI, S6720S-SI, S6720-SI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this command.

Format

e-trunk track bfd-session session-name bfd-session-name

undo e-trunk track bfd-session

Parameters

Parameter	Description	Value
session-name bfd-session-name	Specifies the name of a BFD session.	The value is a string of 1 to 15 case-insensitive characters without spaces. When the string is enclosed with double quotation marks (""), spaces are allowed in the string.

Views

E-Trunk view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

PE1 and PE2 are connected through an E-Trunk. PE1 is in master state and PE2 is in slave state. When PE1 fails and PE2 does not receive any E-Trunk protocol packets from PE1 after the timer expires, PE2 switches from the slave state to the master state.

The status of PE2 changes after the timer expires. During the timeout, user traffic is interrupted. To enable PE2 to rapidly detect the fault and switch its status, run this command to bind a BFD session to an E-Trunk.

After the BFD session is bound to the E-Trunk, the BFD session can rapidly detect the link between PE1 and PE2. If the link fails, the BFD session becomes Down. PE2 then can detect the BFD session status and switch its status to master so that traffic is correctly forwarded.

In this scenario, the Eth-Trunk on PE1 and PE2 supports only one member interface.

Prerequisites

Before using this command, pay attention to the following points:

An E-Trunk and a BFD session must have been configured. BFD for IP must be used; otherwise, the E-Trunk cannot rapidly detect the fault through the BFD session.
The IP addresses of both ends of the E-Trunk must be reachable; otherwise, the BFD session cannot go Up. That is, the BFD session cannot detect the link between PE1 and PE2.

Precautions

After a BFD session is bound to an E-Trunk and AC interfaces on both devices of the E-Trunk are associated with the BFD session, if the AC interface of the master device fails, the BFD session goes Down and traffic is switched to the standby link. If the AC interface recovers within 60 seconds, traffic is immediately switched back to the active link.

Example

# Bind a BFD session named hello to E-Trunk 1.

<HUAWEI> system-view
[HUAWEI] e-trunk 1
[HUAWEI-e-trunk-1] e-trunk track bfd-session session-name hello