Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 604)

Enabling VRRP preemption
You can allow a backup router that is acting as the master to be preempted by another backup router
with a higher priority value.
Default : Preemption is enabled for VRRP, disabled for VRRP-E.
NOTE
If preemption is disabled for VRRP, the owner router is not affected because the owner router always
preempts the active master.
To enable preemption for a virtual router, run the preempt-mode command in virtual-router-group
configuration mode, as shown in the following example:
switch(config-vrrp-group-5)# preempt-mode
Track priority example
Using the figure in VRRP multigroup clusters on page 598 as an example, you can configure interface
ve 10 on Router 1 to track interface 101/2/4, Then, if 101/2/4 goes down, interface ve 10 can respond
by lowering the Router 1 VRRP priority by the track-port priority value. The backup routers detect this
change and negotiate to become the new master, thus providing a master with an uninterrupted path
out of the network.
The following example sets the track port and priority as described above.
1. Enter interface configuration mode and run the following command:
switch(config)# int ve 10
2. Run the following command to enter group configuration mode.
switch(conf-Ve-10)# vrrp-group 1
3. Run the following command to set the track port and priority:
switch(config-vrrp-group-1)# track te 101/2/4 priority 60
Refer also to Track ports and track priority with VRRP and VRRP-E on page 600.
Configuring short-path forwarding
Refer to Short-path forwarding (VRRP-E only) on page 600.
Under the VRRP-E group-configuration level, there is an option to enable short-path-forwarding.
For example, follow these steps:
1. Enter global configuration mode.
switch# config
2. In global configuration mode, entering the int vlan command.
switch(config)# int vlan 10
3. Exit the interface configuration mode by entering the end command.
switch(config-Vlan-10)# end
4. Enter global configuration mode.
switch# config
5. Enter RBridge ID configuration mode.
switch (config)# rbridge-id 101
6. In RBridge ID configuration mode, enter the int ve command.
switch(config-rbridge-id-101)# int ve 10
Enabling VRRP preemption
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