VRRPv3: Object Tracking Integration

Virtual Router Redundancy Protocol (VRRP) enables a group of devices to form a single virtual device to provide redundancy. The LAN clients then can be configured with the virtual device as the default gateway. The virtual device, representing a group of devices, is also known as a VRRP group. The VRRPv3: Object Tracking Integration feature allows you to track the behavior of an object and receive notifications of changes. This module explains how object tracking, in particular the tracking of IPv6 objects, is integrated into VRRP version 3 (VRRPv3) and describes how to track an IPv6 object using a VRRPv3 group. See the “VRRP Object Tracking” section for more information on object tracking.

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Information About VRRPv3: Object Tracking Integration

VRRP Object Tracking

Object tracking is an independent process that manages creating, monitoring, and removing tracked objects such as the state of the line protocol of an interface. Clients such as the Hot Standby Router Protocol (HSRP), Gateway Load Balancing Protocol (GLBP), and VRRP register their interest with specific tracked objects and act when the state of an object changes.

Each tracked object is identified by a unique number that is specified on the tracking CLI. Client processes such as VRRP use this number to track a specific object.

The tracking process periodically polls the tracked objects and notes any change of value. The changes in the tracked object are communicated to interested client processes, either immediately or after a specified delay. The object values are reported as either up or down.

VRRP object tracking gives VRRP access to all the objects available through the tracking process. The tracking process allows you to track individual objects such as a the state of an interface line protocol, state of an IP route, or the reachability of a route.

VRRP provides an interface to the tracking process. Each VRRP group can track multiple objects that may affect the priority of the VRRP device. You specify the object number to be tracked and VRRP is notified of any change to the object. VRRP increments (or decrements) the priority of the virtual device based on the state of the object being tracked.

How VRRP Object Tracking Affects the Priority of a Device

The priority of a device can change dynamically if it has been configured for object tracking and the object that is being tracked goes down. The tracking process periodically polls the tracked objects and notes any change of value. The changes in the tracked object are communicated to VRRP, either immediately or after a specified delay. The object values are reported as either up or down. Examples of objects that can be tracked are the line protocol state of an interface or the reachability of an IP route. If the specified object goes down, the VRRP priority is reduced. The VRRP device with the higher priority can now become the virtual primary device if it has the vrrp preempt command configured. See the “VRRP Object Tracking” section for more information on object tracking.

How to Configure VRRPv3: Object Tracking Integration

Tracking an IPv6 Object using VRRPv3

SUMMARY STEPS

fhrp version vrrp v3
interface type number
vrrp group-id address-family ipv6
track object-number decrement number
end

DETAILED STEPS

Command or Action Purpose

Step 1

fhrp version vrrp v3

Example:


Device(config)# fhrp version vrrp v3

Enables you to configure Virtual Router Redundancy Protocol version 3 (VRRPv3) and Virtual Router Redundancy Service (VRRS) on a device.

Note

When VRRPv3 is in use, VRRPv2 is unavailable.

Step 2

interface type number

Example:


Device(config)# interface GigabitEthernet 0/0/0

Specifies an interface and enters interface configuration mode.

Step 3

vrrp group-id address-family ipv6

Example:


Device(config-if)# vrrp 1 address-family ipv6

Creates a VRRP group for IPv6 and enters VRRP configuration mode.

Step 4

track object-number decrement number

Example:


Device(config-if-vrrp)# track 1 decrement 20

Configures the tracking process to track the state of the IPv6 object using the VRRPv3 group. VRRP on Ethernet interface 0/0 then registers with the tracking process to be informed of any changes to the IPv6 object on the VRRPv3 group. If the IPv6 object state on serial interface VRRPv3 goes down, then the priority of the VRRP group is reduced by 20.

Step 5

end

Example:


Device(config-if-vrrp)# end

Returns to privileged EXEC mode.

Configuration Examples for VRRPv3: Object Tracking Integration

Example: Tracking an IPv6 Object using VRRPv3

In the following example, the tracking process is configured to track the state of the IPv6 object using the VRRPv3 group. VRRP on GigabitEthernet interface 0/0/0 then registers with the tracking process to be informed of any changes to the IPv6 object on the VRRPv3 group. If the IPv6 object state on serial interface VRRPv3 goes down, then the priority of the VRRP group is reduced by 20:


Device(config)# fhrp version vrrp v3
Device(config)# interface GigabitEthernet 0/0/0
Device(config-if)# vrrp 1 address-family ipv6
Device(config-if-vrrp)# track 1 decrement 20

Example: Verifying VRRP IPv6 Object Tracking


Device# show vrrp

Ethernet0/0 - Group 1 - Address-Family IPv4
  State is BACKUP
  State duration 1 mins 41.856 secs
  Virtual IP address is 172.24.1.253
  Virtual MAC address is 0000.5E00.0101
  Advertisement interval is 1000 msec
  Preemption enabled
  Priority is 80 (configured 100)
    Track object 1 state Down decrement 20
  Master Router is 172.24.1.2, priority is 100
  Master Advertisement interval is 1000 msec (learned)
  Master Down interval is 3609 msec (expires in 3297 msec)

Device# show track ipv6 route brief

Track Type        Instance                   Parameter        State Last Change
601   ipv6 route  3172::1/32                 metric threshold Down  00:08:55
602   ipv6 route  3192:ABCD::1/64            metric threshold Down  00:08:55
603   ipv6 route  3108:ABCD::CDEF:1/96       metric threshold Down  00:08:55
604   ipv6 route  3162::EF01/16              metric threshold Down  00:08:55
605   ipv6 route  3289::2/64                 metric threshold Down  00:08:55
606   ipv6 route  3888::1200/64              metric threshold Down  00:08:55
607   ipv6 route  7001::AAAA/64              metric threshold Down  00:08:55
608   ipv6 route  9999::BBBB/64              metric threshold Down  00:08:55
611   ipv6 route  1111::1111/64              reachability     Down  00:08:55
612   ipv6 route  2222:3333::4444/64         reachability     Down  00:08:55
613   ipv6 route  5555::5555/64              reachability     Down  00:08:55
614   ipv6 route  3192::1/128                reachability     Down  00:08:55

Additional References for VRRPv3: Object Tracking Integration

Related Topic	Document Title
Cisco IOS commands	Cisco IOS Master Command List, All Releases
HSRP commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples	Cisco IOS First Hop Redundancy Protocols Command Reference
Troubleshooting HSRP	Hot Standby Router Protocol: Frequently Asked Questions

RFCs


RFCs	Title
RFC 792	Internet Control Message Protocol
RFC 1828	IP Authentication Using Keyed MD5
RFC 5798	Virtual Router Redundancy Protocol

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