[c-nsp] BGP partial routes and partial carrier failures

[Saku Ytti]

On (2014-10-02 12:29 -0700), Bruce Pinsky wrote:

Hi Bruce,

> How about not taking the default from them and set your own default based
> on whatever criteria you chose.  You could, for instance, use Conditional
> Advertisements to inject the default based on the presence or absence of
> routing information from one or the other provider.  You could also use PfR
> to select the outbound path based on availability/performance/cost.

You don't actually need anything this complex. Just recursing static route
will do, and IOS by default recurses.
So both upstreams would advertise to you some prefix they don't originate in
the peer router, maybe their PA network from the core.

Then you'd have something like
ip route 0.0.0.0 0.0.0.0 <pa-prefix>

If one upstream peer gets disconnected from their core, the PA-prefix is no
longer sent via that peer, and it'll now recurse to the other provider.

-- 
  ++ytti