[c-nsp] IPv6 uRPF broken on NCS5500 XR 6.2.3?

[David Hubbard]

Hi all, curious if anyone has run into issues with IPv6 uRPF on NCS5500 and/or XR 6.2.3?  I have an interface where I added:

Ipv4 verify unicast source reachable-via any
ipv6 verify unicast source reachable-via any

and immediately lost my ability to talk to a BGP peer connected to it using a local /126 range; no ping, tcp, etc.  There’s obviously a route in FIB given it’s connected and up, but I did check.  The same issue does not occur with the remote IPv4 peering address on a /30 net, suggesting uRPF for ipv4 doesn’t have the same bug.

Thanks