[c-nsp] HSRP Groups on ASR1k

[Arie Vayner]

There are 2 versions of HSRP v1 and v2.
V1 supports 255 groups and V2 supports 4096. V2 is quite old, and
should be there on any semi-modern platforms.

Both in HSRPv1 and HSRPv2 the virtual MAC is derived from the group
ID. There are some scenarios where we want to use multiple HSRP groups
on the same L2 domain (dual active gateways...), and then we have to
use different MAC (and group).

Most other cases, when L2 domains are seperate, the same group ID can
be reused.

Arie

On 9/28/10, Gert Doering <gert at greenie.muc.de> wrote:
> Hi,
>
> On Tue, Sep 28, 2010 at 01:31:29PM -0400, Benjamin Lovell wrote:
>> > 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"
>>
>> BL> It varies by platform. The 3K series switches for example also use
>> BL> the VLAN ID and will give you 256(i think) unique MACs even if using
>> BL> the same group ID.
>
> This surprises me a bit - because that implies that using a HSRP group
> between a 3K and "something not 3K" will create inconsistent MAC addresses
> between HSRP peers (and I'm not sure whether HSRP can "fix" this or
> will just fail then).
>
> gert
> --
> USENET is *not* the non-clickable part of WWW!
>
> //www.muc.de/~gert/
> Gert Doering - Munich, Germany
> gert at greenie.muc.de
> fax: +49-89-35655025
> gert at net.informatik.tu-muenchen.de
>

-- 
Sent from my mobile device