Dell BigIron RX Series, Руководство по настройке

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BigIron RX Series Configuration Guide 439
53-1002253-01
Configuring optional VSRP parameters
15
Specifying a track port
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 427.
To configure a VRID to track an interface, enter a command such as the following at the
configuration level for the VRID.
BigIron RX(config-vlan-200-vrid-1)# track-port e 2/4
Syntax: [no] track-port ethernet <slot>/<portnum> | ve <num> [priority <num> ]
The priority <num> parameter changes the VSRP priority of the interface. If this interface goes
down, the VRID’s 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
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.
BigIron RX(config-vlan-200-vrid-1)# non-preempt-mode
Syntax: [no] non-preempt-mode
Port transition hold timer
Using this VSRP command will delay the sending of port "up"/"down" events. This command affects
the physical link events. However, the resulting logical link events are also delayed. This is a
per-interface command.
For example, if VSRP is enabled on the port, the ownership would not change until the port status
has remained up or down for the configured amount of time to ensure that minor transient states
of a link do not unintentionally cause a disruptive topology change in the network.