[c-nsp] reverse path filtering doesn't seem to work

[Pete Templin]

Mike wrote:
> Gang,
> 
> I have a 3725 with some t1 interfaces. I want to be a good netizen and 
> establish urpf on my customer facing interfaces to ensure they can't 
> send me spoofed traffic. When I enable 'ip verify unicast source 
> reachable-via rx' however, suddenly I can't ping the router on the other 
> side.  Here's the relevant configs:

I don't know how well it'll work on an unnumbered interface etc., but I 
always add the option 'allow-self-ping' to my commands, i.e. 'ip ve u s 
r r allow-s'.  I suspect that's related to your troubles.

pt