IPV6 problem : nd6_lookup: failed to add route for a neighbor

[Steve Bertrand]

Tuc at T-B-O-H.NET wrote:

> 	But once I brought it all up, I got :
> 
> kernel: nd6_lookup: failed to add route for a neighbor(2001:0470:0007:0028::0001), errno=17

With your exact configuration between two 7.0 boxes, I see no indication 
of this error whatsoever, with the /128 prefix.

> 	The tunnel came up, was passing traffic, but those messages were
> getting out of hand. I tried a prefixlen of 64, and I got:
> 
> 	ifconfig: ioctl (SIOCAIFADDR): Invalid argument

When I attempted to recreate the tunnel with any prefix length other 
than 128, the same ifconfig error appeared as above. It appears as 
though when creating a gif tunnel, the only IPv6 prefix length that is 
valid as far as ifconfig is concerned is /128 even though the link's 
prefix is /64 even in 7.

Steve