H3C Technologies H3C S3600 Series Switches - Manual (Page 246)

1-4
Figure 1-1 The uplink of the master switch fails
Switch A
Switch B
Internet
Master
Backup
Master
Backup
VLAN 10
Gateway: 10.1.1.1/24
VLAN 20
Gateway: 20.1.1.1/24
The uplink port
of Switch A fails
Using VRRP together with the Auto Detect function, you can change the priority of a switch according to
the uplink status. On the master switch of the VRRP backup group, you can use the Auto Detect
function to detect the paths between the master switch and other networks, and control the priority of
the master switch according to the returned reachable/unreachable information, thus implementing
automatic master/backup switchover and guaranteeing the communication is not interrupted.
z The master switch keeps as Master when the detected group is reachable.
z The priority of the master switch decreases and thus becomes a Backup when the detected group
is unreachable.
You need to create the detected group and perform VRRP-related configurations before the following
operations.
Follow these steps to configure the auto detect function for VRRP:
To do… Use the command… Remarks
Enter system view system-view —
Enter VLAN interface view interface Vlan-interface vlan-id —
Enable the auto detect function
for VRRP vrrp vrid virtual-router-id track detect-group
group-number [ reduced value-reduced ]
Required
Auto Detect Implementation in VLAN Interface Backup
VLAN interface backup means backing up the VLAN interfaces on a devices. Usually, the master VLAN
interface transmits traffic, while the backup VLAN interfaces stay standby. When the master VLAN
interface or the link connected to the VLAN interface fails and thus cannot transmit traffic, the backup
VLAN interface can be used for communication. In this way, the network reliability is improved.
As shown in 0 , Switch A has two VLAN interfaces: VLAN-interface 1 and VLAN-interface 2. The two
VLAN-interfaces back up each other. Normally. VLAN-interface 1 transmits traffic, while VLAN-interface