the decrement of vrrp object tracking?

[vcp754467]

I'm trying to understand how Virtual Router Redundancy Protocol (VRRP) works but confused by the object tracking.

The document, First Hop Redundancy Protocols Configuration Guide, Cisco IOS Release 15S - Configuring VRRP [Cisco IOS 15.5S] - Cisco , described the commnadline "vrrp group track object-number [decrement priority]" but i'm not certain about the meaning.

does the "decrement priority" indicate that if this tracked object appear then the vrrp priority increase?

Therefore, if configuration "vrrp 9 track 30 decrement 10" is set on a router interface, then the vrrp priority will increase 10 because "object 30" shows up. 

and vice versa?

sorry for the dumb question..

[vcp754467]

(sorry the system posted the content twice...)

[pman]

Hi,

in your case:

if track status=down then the VRRP priority decremented by 10

if track status=up then VRRP priority change back to 100

Example:
interface GigabitEthernet0/0
ip address 1.1.1.1 255.255.255.0
vrrp 1 ip 1.1.1.254
vrrp 1 priority 110
vrrp 1 track 1 decrement 20
!
track 1 interface GigabitEthernet0/0 line-protocol

track is down:
R3(config)#int gi0/0
R3(config-if)#shutdown

R3(config-if)#do show vrrp
GigabitEthernet0/0 - Group 1
State is Init
Virtual IP address is 1.1.1.254
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 90 (cfgd 110)
Track object 1 state Down decrement 20
Master Router is unknown, priority is unknown
Master Advertisement interval is unknown
Master Down interval is unknown

track is up:
R3(config-if)#no shut
R3(config-if)#do show vrrp
GigabitEthernet0/0 - Group 1
State is Master
Virtual IP address is 1.1.1.254
Virtual MAC address is 0000.5e00.0101
Advertisement interval is 1.000 sec
Preemption enabled
Priority is 110
Track object 1 state Up decrement 20
Master Router is 1.1.1.1 (local), priority is 110
Master Advertisement interval is 1.000 sec
Master Down interval is 3.570 sec