[c-nsp] HSRP Groups on ASR1k

[Matthew Melbourne]

Yes, I too expected the MAC to be the same to a given group number, unless
there are other factors at play here, e.g. per-VLAN/VRF/platform
limitations. I expected only two MACs to be used (one for each group). 

-----Original Message-----
Message: 1
Date: Tue, 28 Sep 2010 17:48:16 +0100
From: Phil Mayers <p.mayers at imperial.ac.uk>
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] HSRP Groups on ASR1k
Message-ID: <4CA21C50.9090209 at imperial.ac.uk>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 28/09/10 17:35, Benjamin Lovell wrote:
> I haven't looked into this on the ASR1K but what the message is
> telling you is that the NIC can only program 28 MAC addresses and you
> have used up the limit. If you add more sub-interfaces with HSRP then
> bad things will start to happen. Drops, punt to CPU, not sure as I
> have not looked into it on this platform but nothing good.

Is this right?

Isn't the HSRP MAC the same for a given group number, regardless of 
which sub-int?

We run all our interfaces (not ASR1k though) in "standby group 0"

>
> This could be a software limitation that was addressed or is planed
> to be addressed in later code releases or it could be a hard limit of
> the NIC used on the SPAs. I would open a case with the TAC to have
> them talk to the devs about this and see if it will be important to
> you.
>
> BTW - not clear on the part where you said you are using HSRP groups
> 1 and 2 on the customer sub-ints. You should use a unique standby
> group for each HSRP instance. If you are not this *may have something
> to do with your problem.

Why? Using a different standby group per sub-int will surely definitely 
run you over the mac receive filter size limit? What's the problem using 
the same group number on different interfaces?