backup (VSRP)

Configures the device as a Virtual Switch Redundancy Protocol (VSRP) backup for the Virtual Routing ID (VRID) or changes the backup priority and the track priority.
Syntax
backup [ priority priority-number [ track-priority track-number ] ]
no backup [ priority priority-number [ track-priority track-number ] ]
Command Default

The default backup priority for the VSRP VRID is 100.

The default track priority for all track ports is 5.

Parameters
priority priority-number
Configures the backup priority for the VSRP VRID. The range is from 6 through 255. The default value is 100.
track-priority track-number
Configures the track priority for the VSRP VRID. The range is from 1 through 254. The default value is 5.
Modes

VSRP VRID configuration mode

Usage Guidelines

This configuration is important because in VSRP, all devices on which a VRID are configured are backups. The master is then elected based on the VSRP priority of each device. There is no "owner" device as there is in VRRP.

The backup priority is used for election of the master. The VSRP backup with the highest priority value for the VRID is elected as the master for that VRID. If two or more backups are tied with the highest priority, the backup with the highest IP address becomes the master for the VRID.

The track priority is used with the track port feature. When you configure a VRID to track the link state of other interfaces, if one of the tracked interface goes down, the software changes the VSRP priority of the VRID interface. The software reduces the VRID priority by the amount of the priority of the tracked interface that went down. For example, if the VSRP interface priority is 100 and a tracked interface with track priority 60 goes down, the software changes the VSRP interface priority to 40. If another tracked interface goes down, the software reduces the VRID priority again, by the amount of the tracked interface track priority.

The no form of the command without any options removes the device as the backup. The no form of the command with the options resets the backup priority value and the track priority value to the default values.

Examples

The following example configures the backup priority as 75.

device(config)# vlan 200
device(config-vlan-200)# tagged ethernet 1/1/1 to 1/1/8
device(config-vlan-200)# vsrp vrid 1
device(config-vlan-200-vrid-1)# backup priority 75
device(config-vlan-200-vrid-1)# activate

The following example configures the backup priority as 100 and the track priority as 2.

device(config)# vlan 200
device(config-vlan-200)# tagged ethernet 1/1/1 to 1/1/8
device(config-vlan-200)# vsrp vrid 1
device(config-vlan-200-vrid-1)# backup priority 100 track-priority 2
device(config-vlan-200-vrid-1)# activate