Configuration Guide User guide

650 FastIron Configuration Guide
53-1002494-02
VSRP
Syntax: [no] backup [priority <value>] [track-priority <value>]
Specifying a track port setting
You can configure the VRID on one interface to track the link state of another interface on the
device. This capability is useful for tracking the state of the exit interface for the path for which the
VRID is providing redundancy. Refer to “VSRP priority calculation” on page 636.
To configure a VRID to track an interface, enter a command such as the following at the
configuration level for the VRID.
Brocade(config-vlan-200-vrid-1)#track-port ethernet 2/4
Syntax: [no] track-port ethernet [<slotnum>/]<portnum> | ve <num> [priority <num>]
The priority <num> parameter changes the VSRP priority of the interface. If this interface goes
down, the VRID VSRP priority is reduced by the amount of the track port priority you specify here.
NOTE
The priority <num> option changes the priority of the specified interface, overriding the default track
port priority. To change the default track port priority, use the backup track-priority <num>
command.
Disabling or re-enabling backup pre-emption setting
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.
Brocade(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.