HSRP for remote building

[shaucall46]

We are currently running HSRP in our core with 2 devices within 1 HSRP Group which is fine.

We have an adjacent building where all hosts use this HSRP instance as their Gateway which works fine.

However we have an issue in that SRST is failing in remote building as when connectivity is lost to core(CUCM) the default gateway for all the hosts is unreachable.

The Core switch in the remote building(lets call this SW3) has SVIs configured but device is not part of HSRP group.

I can add this device to HSRP group but have concerns:-

• I never want this device SW3 to be the active router for the whole campus which I can do with setting the priority level to be the lowest is this the best practise or should I look at interface tracking.
  
• If I add in SW3 to HSRP group will it have any impact/outage on current setup.
  
• Any other thoughts on doing this, driver is to get SRST operational if we lose connectivity between buildings.
  

Thanks

[devils_advocate]

Can you post a diagram of your topology?

[shaucall46]

[Parvesh Paliwal]

what I suggest on this is : if you dont want sw3 to be the active router for the whole campus, you change the priority of the switch to a value that it will be active only as the last choice.

Adding a device to HSRP should not cause a downtime, as the active gateway will be hosted on a different device. You can try the same setup in GNS as well to make a best practice.