Brocade TurboIron 24X Series Configuration Guide - Manual (Page 351)

Brocade TurboIron 24X Series Configuration Guide 317
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Virtual Switch Redundancy Protocol (VSRP)
Disabling or re-enabling backup pre-emption
By default, a backup that has a higher priority than another backup that has become the master
can preempt the master, and take over the role of master. If you want to prevent this behavior,
disable preemption.
Preemption applies only to backups and takes effect only when the master has failed and a backup
has assumed ownership of the VRID. The feature prevents a backup with a higher priority from
taking over as master from another backup that has a lower priority but has already become the
master of the VRID.
Preemption is especially useful for preventing flapping in situations where there are multiple
backups and a backup with a lower priority than another backup has assumed ownership, because
the backup with the higher priority was unavailable when ownership changed.
If you enable the non-preempt mode (thus disabling the preemption feature) on all the backups,
the backup that becomes the master following the disappearance of the master continues to be
the master. The new master is not preempted.
To disable preemption on a backup, enter a command such as the following at the configuration
level for the VRID.
TurboIron(config-vlan-200-vrid-1)#non-preempt-mode
Syntax: [no] non-preempt-mode
Suppressing RIP advertisement from backups
Normally, for Layer 3 a VSRP backup includes route information for a backed up IP address in RIP
advertisements. As a result, other Layer 3 Switches receive multiple paths for the backed up
interface and might sometimes unsuccessfully use the path to the backup rather than the path to
the master.
You can prevent the backups from advertising route information for the backed up interface by
enabling suppression of the advertisements.
NOTE
This parameter applies only if you specified an IP address to back up and is valid only on Layer 3
Switches.
To suppress RIP advertisements, enter the following commands.
Router2(config)#router rip
Router2(config-rip-router)#use-vrrp-path
Syntax: [no] use-vrrp-path
VSRP-aware interoperablilty
The vsrp-aware tc-vlan-flush command should be used in network configurations in which the
switch operates as the VSRP-Aware device connecting to the other devices configured as a VSRP
master.
The command is available at the VLAN level, and is issued per a specific VRID, as shown here for
VRID 11.
TurboIron(config-vlan-10)#vsrp-aware vrid 11 tc-vlan-flush