KRT: Received route with strange next-hop

[Brian Rak]

I'm trying to figure out why BIRD is throwing this error every time it 
scans the kernel routing table:

<ERR> KRT: Received route 216.155.132.254/32 with strange next-hop 
45.63.4.188
<WARN> Netlink: File exists

I have two routes relevant to this one:

# ip route | grep 45.63.4.188
45.63.4.188 dev veth0 scope link
216.155.132.254 via 45.63.4.188 dev veth0 proto bird

The 45.63.4.188 route was added by me (manually), the 216.155.132.254 
was added via BIRD (BIRD learned it via BGP).

So, to me this looks like bird adding the route to the kernel, then 
getting confused why the route exists.  Aside from this warning, 
everything appears to be working fine.  Linux routes the traffic 
properly, BIRD readvertises this route properly.

Any thoughts here?  I think I can probably suppress this warning by 
removing the 'ng->scope == SCOPE_HOST' check from netlink.c, but I'm not 
entirely sure why that's there to begin with.