[c-nsp] Sharing HSRP group numbers across multiple HSRP instances

[Tim Durack]

On Tue, Dec 23, 2008 at 5:27 AM, Phil Mayers <p.mayers at imperial.ac.uk> wrote:
> On Mon, Dec 22, 2008 at 10:07:13PM +0000, Justin Shore wrote:
>>
>> Arie & Christian,
>>
>> Thanks for the replies.  So re-using HSRP group #s doesn't create any
>
> Correct, it works fine.
>
>> conflicts?  That's good to know.  It also won't reduce the load?  That's
>> unfortunately.  For some reason I had it in my mind that you could create
>> some sort of collective HSRP instance over a common L2 infrastructure that
>> would share hellos and switch as one common unit. It would be list MST for
>> HSRP essentially.
>
> That's the "HSRP multiple group optimisation" which is available on SXI and
> SRsomething, but sadly it supports routed subints on the same master
> physical int *only* - no SVIs:
>
> int Gi1/1.1
>  standby name foo
>  ! other config
> int Gi1/1.2
>  standby follow foo
>  ! other config
>
> Attempting to configure on SVIs gives some random error message about
> "different physical parent interfaces". I can't see any reason for the
> restriction - I keep meaning to put an RFE in.

Why would you expect it to work on an SVI? Nothing else does...

After discovering this we put in a feature request. Not expecting it
to go anywhere though.

Tim:>