[c-nsp] BFD alternative

[Jason Lixfeld]

We're in the the process of turning up an MPLS network using ASR9ks and ME3600s.  We're looking to get away from L2 and interconnect all the devices at L3.  To facilitate this, we were originally going to use unnumbered on all the PE-PE, P-P, P-PE links but we just recently discovered that BFD isn't supported on unnumbered Gig/TenGig interfaces.

We're just doing L2/L3VPN here.  No VPLS, TE, etc at this point.  That said, if we tune down our SPF timers (ISIS) and enable LDP IGP Sync and LDP session protection, is that a pretty good compromise?

Thanks in advance.