VRRP can be configured
to have the existing router preempted. This means that if a new VRRP router is added to the network
with priority higher than the existing routers, the new router will
become the Master. If preemption is disabled, then the new router
will not become the Master. This router will become the Master only
when the current Master is down, that is, only when it does not
receive any advertisement packets from the current Master. By default,
Preempt Mode is enabled. For setup, refer to Figure VRRP- Topology
1.
- Execute the following commands in Switch
1 and Switch 2 to enable preempt mode.
Type the following:
- Enter the Global Configuration
Mode.
iS5comm# configure terminal
- Enable VRRP and enter the VRRP Configuration Mode.
iS5comm(config)# router vrrp
- Select an interface to configure VRRP and
enter the VRRP Interface Configuration
Mode.
iS5comm(config-vrrp)# interface vlan 2
- Enable the Preemption mode.
iS5comm(config-vrrp-if)# vrrp 1 preempt
- Enter the VRRP Interface
Configuration Mode.
iS5comm(config-vrrp-if)# end
- View the preemption status in Switch 1 using the following
command.
Type the following:
iS5comm# show vrrp interface vlan 2 detail
vlan2 - vrID 1
---------------
State is Master
Virtual IP address is 12.0.0.1
Virtual MAC address is 00:00:5e:00:01:01
Master router is 12.0.0.1
Associated IP Addresses :
----------------------
12.0.0.5
12.0.0.6
Advertise time is 1000 milli secs
Current priority is 200
Configured priority is 200, may preempt
- View the preemption status in Switch 2 using the following
command.
Type the following:
iS5comm# show vrrp interface vlan 2 detail
vlan2 - vrID 1
---------------
State is Backup
Virtual IP address is 12.0.0.2
Virtual MAC address is
Master router is 12.0.0.1
Associated IP Addresses :
----------------------
12.0.0.5
12.0.0.6
Advertise time is 1000 milli secs
Current priority is 150
Configured priority is 150, may preempt