[c-nsp] Suspending connected routes

[Eshan Bhide]

Hi guys,

Is there a way I could suspend connected routes for an interface under 
an ospf process. The idea being, if the upstream interface goes down, 
the prefix should be withdrawn from router A and all traffic fails to 
the redundant router B which would still advertise the prefix in the 
vpnv4 cloud.

I can do this with ISIS. To demonstrate, RouterA(R1) --(ethernet)-- 
DSLAM(R2).  When the link between the two routes is up:

R1#sh ip route vrf DSLAM

Routing Table: DSLAM

       x.x.0.0/28 is subnetted, 1 subnets
i L1     x.x.67.208 [115/20] via x.x.67.210, 00:00:01, Ethernet0/0.1205

R1#sh isis rib

IPv4 local RIB for IS-IS process

IPV4 unicast topology base (TID 0, TOPOID 0x2) =================

x.x.67.208/28
   [115/L1/20] via x.x.67.210(Ethernet0/0.1205), from x.x.67.210, tag 0, 
LSP[1/20]
               (installed)

Advertised out via  vpnv4:

R1#sh ip bgp vpnv4 vrf DSLAM

      Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 9942:7 (default for vrf DSLAM)
  *>  x.x.67.208/28  x.x.67.210            20         32768 ?



When the link is down:
R2(config-subif)#shut


R1#sh isis rib


IPv4 local RIB for IS-IS process

IPV4 unicast topology base (TID 0, TOPOID 0x2) =================

R1#sh ip bgp vpnv4 vrf DSLAM

R1#sh ip route vrf DSLAM

Routing Table: DSLAM
Gateway of last resort is not set


The prefix gets withdrawn. I can do a no isis advertise-prefix or an ip 
unnumbered command to achieve the above.

However I'm struggling to find a way to do this in OSPF over non 
point-to-point links. Any ideas?

Cheers,
Eshan