[j-nsp] Fate sharing between BGP and RSVP

[Rob Foehl]

On Tue, 13 Sep 2016, Chuck Anderson wrote:

> I guess I don't understand what you are trying to accomplish then.
> Ttaffic engineering specific routes is exactly what RSVP is used for.
> The MPLS path should be torn down if there is no available
> RSVP-capable route.  Did you try just not configuring RSVP on the
> interfaces that can't support MPLS?

The LSP is torn down; the BGP session carrying a bunch of routes for which 
that LSP is the only viable forwarding path survives.  (RSVP is only 
configured where it ought to be, no "interfaces all" or anything like 
that.)

The goal is for the BGP-learned routes to disappear along with the LSP -- 
preferably by just tearing the session down with it, but otherwise 
invalidating the next-hops would suffice.

I have another idea in my back pocket if this isn't workable, but that 
involves turning a bunch of P routers into full BGP RRs...

-Rob