User guide

166 ExtremeWarePx1 1.2 Command Reference Guide
Commands for Configuring Redundancy
VRRP Properties
Each application switch maintains three properties for each conÞgured VRRP class.
¥ The switchÕs priority for that VRRP class
The switch with the higher priority for a given VRRP class is the primary device for that class; the
switch with the lower priority is the secondary device for the class. The primary device will initially
be active for the VRRP class (handling the virtual services in that class); the secondary device will
initially be the backup. If the active switch fails, the backup switch takes over automatically.
The default value for this property is 100; the value can be changed with the configure vrrp
priority
command.
The priority 255 is called master priority. Whenever a switch with master priority is available, that
switch handles the VRRP class.
¥ Whether the switch should preempt the active system when it has higher priority for the VRRP class
If a transition occurs because the primary device goes down, this property determines what happens
when the primary device comes back up. This property is relevant only on the primary switch for
the VRRP class and only if that switch does not have master priority. (A switch with master priority
always preempts the active system when it comes back up.)
This property can be set to either preempt or dont-preempt.
The default value for this property is dont-preempt; the value can be changed with the configure
vrrp preempt|dont-preempt
command.
¥ The frequency of advertisement intervals for the VRRP class
Each switch periodically sends VRRP advertisements to the other switch via the Gigabit port, thus
checking to see whether the other switch is in operation. This property controls the frequency of
these checks; the lower the value, the faster failover occurs when the active switch goes down. The
default value for this property is 1 second. The value can be changed with the configure vrrp
advertisement-interval
command.
VRRP Automatic Synchronization
VRRP automatic synchronization (auto-sync) allows you to designate one Px-series application switch
as the master switch and the other as the backup. Automatic synchronization ensures that both switches
have the same conÞguration for servers, server groups, services, domains, and pattern rules.
Synchronization is performed by copying conÞguration from the master switch to the backup switch.
When automatic synchronization is enabled:
¥ If services have already been conÞgured on the master switch, you can issue the configure vrrp
auto-sync forcesync
command on the master switch to synchronize the backup switch.
ConÞguration commands for servers, server groups, services, domains, and pattern rules are sent
Value Meaning
preempt When the primary device comes back up, it automatically takes over as active and the
secondary device becomes the backup once again
dont-preempt The secondary device continues being active after the primary device comes up; the primary
device is then the backup