[c-nsp] HSRP and routing asymmetry

[Lincoln Dale]

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.



cheers,

lincoln.