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Can't upgrade MSFC2 IOS because of HSRP 16 Group Limitation

I recently attempted to upgrade to IOS of my 6500 MSFC2 from 12.1(7a)E1 to 12.1(13)E1 but was unsuccessful because I have more than 16 HSRP Groups currently configured. I have about 25 VLAN's configured with a seperate HSRP group for each.

What is the best way to proceed with a reconfiguration of the HSRP groups to allow the upgrade? So, I assign mulitple VLAN's to just a couple of HSRP groups? Perhaps Group 1 for ODD vlans and Group 2 for even VLAN's? Is there a way to perform the reconfiguration without effecting access for the VLAN's?

Thanks for your help.

CATOS 7.4.2

MSFC2 IOS 12.1(7a)E1

Cisco Employee

Re: Can't upgrade MSFC2 IOS because of HSRP 16 Group Limitation

The maximum number of unique HSRP groups ID supported on

Sup2/MSFC2 is 16 . This is a hardware limitation and cannot be changed.

Before 12.1(8a)E, the software allowed creation of more than 16 unique HSRP groups on Supervisor based systems. This a software bug which has

since been fixed. If you are upgrading from a pre-12.1(8a)E release to a later release and you have configured more than 16 HSRP group, make sure you

plan for this software fix by following the 16 HSRP unique group ID limit.

But you can define the same HSRP group ID on multiple interfaces and they

share the same HSRP Virtual MAC address. In most modern LAN Switches,

we would have no issues since they maintain per-vlan MAC address table.

But if your network contains any 3rd Party switches which maintains a system

wide MAC-address table regardless of VLAN then you may have problems.