[c-nsp] HSRP and routing asymmetry

[Tim Durack]

On Thu, Nov 20, 2008 at 6:15 PM, Lincoln Dale <ltd at cisco.com> wrote:
>
>
> Michael Jager wrote:
>>
>> 1. announce both prefixes into the core from both agg devices, and have
>> the core prefer the announcement from the agg device that is currently the
>> HSRP active router for a given prefix, or:
>>
>> 2. announce the prefix only from the agg device that is currently the HSRP
>> active router for that prefix.
>>
>> The latter option seems easy enough to do with conditional announcements,
>> but that will track a route received from somewhere else (presumably the
>> core). I could announce a dummy prefix from one agg device to the other; but
>> I'd really like to inextricably link the announcement to the HSRP state
>> somehow.
>
> my recommendation would be to advertise the subnet from both, but use EEM to
> make the HSRP active advertise it at a lower metric.
>
> as an alternative to that, use your c6k in the agg as an active/active pair
> with VSS then you can use all links active.  would require Sup720 though, i
> believe.

VS-S720-10G for VSS.