vrrp vrid backup-forward
Function
The vrrp vrid backup-forward command enables the backup device in a VRRP backup group to forward traffic.
The undo vrrp vrid backup-forward command disables the backup device in a VRRP backup group from forwarding traffic.
By default, the backup device in a VRRP backup group is disabled from forwarding traffic.
Format
vrrp vrid virtual-router-id backup-forward
undo vrrp vrid virtual-router-id backup-forward
Only 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 support this command.
Parameters
| Parameter | Description | Value |
|---|---|---|
virtual-router-id |
Specifies the ID of a VRRP backup group. |
The value is an integer ranging from 1 to 255. |
Views
GE sub-interface view, MultiGE sub-interface view, XGE sub-interface view, 25GE sub-interface view, 40GE sub-interface view, 100GE sub-interface view, Eth-Trunk sub-interface view, VE sub-interface view
Usage Guidelines
Usage Scenario
On large aggregation networks of enterprises, terminal users use active and standby links to access aggregation devices that have a VRRP backup group deployed. The aggregation device connects to the active link is the master device, and that connects to the standby link is the backup device. If the active link or the master device fails, a link switchover occurs. However, the master/backup switchover in the VRRP backup group has not yet completed. Therefore, a traffic interruption occurs and lasts for a short period.
To prevent traffic interruptions in such scenarios, run the vrrp vrid backup-forward command to enable the backup device in a VRRP backup group to forward traffic. This configuration ensures carrier-class reliability.
Prerequisites
A VRRP backup group has been created using the vrrp vrid virtual-ip command in the interface view.
Precautions
The backup device can forward traffic with the destination MAC address being the virtual MAC address. If a downstream switch broadcasts a packet with the destination MAC address being the virtual MAC address, the backup device will also forward this packet. Therefore, two copies of this packet will be sent. To prevent duplicate traffic, do not run the vrrp vrid backup-forward command in scenarios other than the one where high reliability is required on large aggregation networks of enterprises.
Example
# Create VRRP backup group 1 on GE0/0/2.1 and enable the backup device in the VRRP backup group to forward traffic.
<HUAWEI> system-view
[HUAWEI] interface gigabitethernet 0/0/2.1
[HUAWEI-GigabitEthernet0/0/2.1] vrrp vrid 1 virtual-ip 10.1.1.100
[HUAWEI-GigabitEthernet0/0/2.1] vrrp vrid 1 backup-forward