preference (VSI-BGP-SITE view)

Function

The preference command configures a priority for a multi-homing site.

The undo preference command restores the default priority of a VPLS multi-homing site.

By default, the priority of VPLS multi-homing sites is 100.

Format

preference preference

undo preference [ preference ]

Parameters

Parameter	Description	Value
preference	Specifies a priority for a multi-homing site.	The value is an integer ranging from 1 to 65535. A greater priority value indicates a higher priority.

Parameter

Description

Value

preference

Specifies a priority for a multi-homing site.

The value is an integer ranging from 1 to 65535.

A greater priority value indicates a higher priority.

Views

VSI-BGP-SITE view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
l2vpn	write

Usage Guidelines

Usage Scenario

VPLS multi-homing prevents routing loops by adjusting link priorities to ensure that one access link of a multi-homed CE is in the active state and the other access links in the blocked state. The link-priority-affecting factors are listed in descending order of influence as follows:

1.ACS: AC interface status, which is determined by the physical interface status

2.PREF: multi-homing site priority

3.PE-ID: If no BGP router ID is configured, the system router ID is used by default. If a BGP router ID is configured, it is used as the PE-ID.

By default, no priority is configured for any multi-homing site. After you create a multi-homing site, run the preference command to configure a priority for the site.

Prerequisites

A multi-homing site ID has been configured using the site-id site-id command.

Precautions

If the preference command is run more than once, the latest configuration overrides the previous one.
If a CE is multi-homed to PEs, configuring different priorities for the same multi-homing site on different PEs is recommended.

Example

# Configure a priority of 100 for the multi-homing site named company1.

<HUAWEI> system-view
[~HUAWEI] mpls
[*HUAWEI-mpls] quit
[*HUAWEI] mpls l2vpn
[*HUAWEI-l2vpn] quit
[*HUAWEI] vsi vsi1
[*HUAWEI-vsi-vsi1] pwsignal bgp multi-homing
[*HUAWEI-vsi-vsi1-bgp] route-distinguisher 192.168.1.1:1
[*HUAWEI-vsi-vsi1-bgp] site name company1
[*HUAWEI-vsi-vsi1-bgp-site-company1] site-id 20
[*HUAWEI-vsi-vsi1-bgp-site-company1] preference 100