[c-nsp] BFD aware VRF

[Justin Shore]

Luan Nguyen wrote:
> I did try with an ethernet link between PE and CE, and bfd config looks
> good.

Unless you're Ethernet links are 1Q trunks like what you'd have between 
a site with a pair of redundant routers doing both L3 and access layer 
connections (FHRPs).  SRC removed BFD on SVI support, as did SXH on the 
ME6524s.

Yes, I'm beating a dead horse but it aggravates me nonetheless.  I need 
to upgrade to SRC but I am going to lose BFD support as soon as I do, 
pushing my recovery times up into seconds; far from the milliseconds 
Cisco sold us on when they blessed this design.

Justin