VRRP - Configure the Virtual Routing Redundancy Protocol

The VRRP configuration is similar to the HSRP, with a few slight differences. For example, there are no
ACTIVE and STANDBU, but MASTER and BACKUP router, as shown below:
#show vrrp brief
Interface          Grp Pri Time  Own Pre State   Master addr     Group addr
Fa0/0              1   200 3218       Y  Master  172.25.12.1      172.25.12.22
Fa0/0              2   100 3609       Y  Backup  172.25.12.2      172.25.12.11

TIMERS are a bit different to configure. You need to tell Master to ADVERTISE the Hello Timer value to the Backup,
and tell the Backup to LEARN the Hello Timer from the Master:
(config-if)#vrrp 1 timers advertise 10
(config-if)#vrrp 2 timers learn
*Router is Mater for VRRP Group 1, and Backup for VRRP Group 2

VRRP Authentication is configured PER GROUP using the command "vrrp X authentication text PASSWORD", and the debug
on the VRRP Pair router is as follows (before the authentication is configured on BOTH):
ES-MAT-AES-SR02#debug vrrp
*Nov 13 15:04:37.585: VRRP: Grp 2 Advertisement from 172.25.12.1 has incorrect authentication type 1 expected 0
*Nov 13 15:04:38.001: VRRP: Grp 1 sending Advertisement checksum EBE4
*Nov 13 15:04:38.585: VRRP: Grp 2 Advertisement from 172.25.12.1 has incorrect authentication type 1 expected 0
*Nov 13 15:04:39.001: VRRP: Grp 1 sending Advertisement checksum EBE4
*Nov 13 15:04:39.585: VRRP: Grp 2 Advertisement from 172.25.12.1 has incorrect authentication type 1 expected 0
*Nov 13 15:04:40.001: VRRP: Grp 1 sending Advertisement checksum EBE4
*Nov 13 15:04:40.585: VRRP: Grp 2 Advertisement from 172.25.12.1 has incorrect authentication type 1 expected 0
*Nov 13 15:04:40.973: VRRP: Grp 2 sending Advertisement checksum 87E5
*Nov 13 15:04:41.001: VRRP: Grp 1 sending Advertisement checksum EBE4
*Nov 13 15:04:41.585: VRRP: Grp 2 Advertisement from 172.25.12.1 has incorrect authentication type 1 expected 0
*Nov 13 15:04:42.001: VRRP: Grp 1 sending Advertisement checksum EBE4
ES-MAT-AES-SR02#u all
All possible debugging has been turned off

At the end the configuration on the interface will look similar to the HSRP config:
interface FastEthernet0/0
 ip address 172.25.12.2 255.255.255.0
 vrrp 1 description MAT1
 vrrp 1 ip 172.25.12.22
 vrrp 1 timers learn
 vrrp 1 authentication cisco
 vrrp 2 description MAT2
 vrrp 2 ip 172.25.12.11
 vrrp 2 timers advertise 10
 vrrp 2 priority 200
end

!!!IMPORTANT DIFFERENCE between HSRP and VRRP: VRRP has Preempt enabled by default on Cisco devices!