Solved: HSRP Tracking

drnteam · ‎07-22-2008

Hi,

What is the purpose of interface tracking in HSRP? How it works? Will the normal HSRP works if tracking is configured?

rsgamage1 · ‎07-22-2008

Interface tracking enables HSRP process to monitor additional interfaces, the status of which will dynamically change the HSRP priority(Active/Standby).

For e.g. imagine the following scenario.

If you have two serial links to two different ISPs(assume primary/backup Internet connections) connected via two different routers, it would be interesting to have the serial interface connecting to your primary ISP tracked in order to minimize service interruption to your local users. If this serial interface goes down, your backup router can take over the gateway functionality to your local network, while maintaining the connectivity to the secondary ISP(backup).

Users would still be able to access Internet via the backup router(through Secondary ISP) thanks to the interface tracking functionality in HSRP.

To answer your 2nd question:

Yes, you can consider interface tracking as part of the 'Normal' HSRP.

For more information: try http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094a91.shtml#intracking

HTH

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Giuseppe Larosa · ‎07-22-2008

Hello,

tracking is the only for HSRP to detect some changes in the routing table.

HSRP isn't a real routing protocol it just provides a default gateway at L3 and L2.

tracking allows to sync the HSRP priority to the good state of one or more uplinks. So combining tracking and preemption HSRP Active role can be taken by the router with the best current connectivity to the core providing better performance

In modern IOS you can track more then simple interface state but the principle is the one explained above

Hope to help

Giuseppe

Giuseppe Larosa · ‎07-22-2008

Hello,

and HRSP work with tracking, work better with it

Hope to help

Giuseppe

sharma16031981 · ‎06-08-2010

hello,

could you please explain about the scenario where this feature would be required and also what will be the effect if interface tracking not used.

In normal scenario everything looks working fine without tracking.

Thanks,

Hemant Sharma

rsgamage1 · ‎07-22-2008

Interface tracking enables HSRP process to monitor additional interfaces, the status of which will dynamically change the HSRP priority(Active/Standby).

For e.g. imagine the following scenario.

If you have two serial links to two different ISPs(assume primary/backup Internet connections) connected via two different routers, it would be interesting to have the serial interface connecting to your primary ISP tracked in order to minimize service interruption to your local users. If this serial interface goes down, your backup router can take over the gateway functionality to your local network, while maintaining the connectivity to the secondary ISP(backup).

Users would still be able to access Internet via the backup router(through Secondary ISP) thanks to the interface tracking functionality in HSRP.

To answer your 2nd question:

Yes, you can consider interface tracking as part of the 'Normal' HSRP.

For more information: try http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094a91.shtml#intracking

HTH

drnteam · ‎07-22-2008

Hi,

The information was really helpful.

Is it necessay to have both the links in the same router. In my setup the link A and B are in differnet routers. Can we track those interface whcih are in different routers. And both routers are connected to my LAN.

senthuran · ‎07-22-2008

HSRP provides router level redundancy,if your Link A on Router1 goes down,HSRP detects the failure and make RouterB as Active where your LinkB is terminated.

You can monitor the Interface on different routers and thats how it works.