[c-nsp] HSRP, and the router on the other side...

[Phil Mayers]

On 03/30/2010 01:07 AM, Andy Koch wrote:
>>
>> Depending on what routing protocol you are using you could write an EEM
>> applet to modify a route-map changing the advertised route metric when HSRP
>> master/slave status changes, but honestly I wouldn't bother - instead, just
>> deal with the issue.
>
> If you are going to force all the traffic one way, why make it hard on
> yourself with EEM.  Set a priority on the HSRP group and allow preempt
> so you know which is to be the active router (unless it fails), then
> cost accordingly on your choice of dynamic routing protocols.

Well, obviously that won't move around as the master/slave status 
changes, but if that's good enough for you, then sure.

As I said, I wouldn't even do that personally. HSRP doesn't work that 
way, the locally connected route is "up" and will always override, e.g. 
in the following topology:

offsite -- router-slave -- router-master
              |             |
              \--- subnet --/

...traffic from "offsite" will always be routed out of router-slave; no 
amount of fiddling with route metrics will help you there. You could do 
something awful like have the HSRP master advertise more specifics, but 
honestly... yuck...