>Tried to setup an unnumbered tunnel (gif v6 over v4) between
>netbsd-current and a freebsd-2.2.8/Kame machine, and got into a
>bit of trouble on the netbsd machine.  The netbsd machine didn't
>manage to do neighbour discovery (of the freebsd machine at the
>other end) over the tunnel interface (gif0). Got somehting like:
>ioctl not supported for device message.
>Solved my problem by numbering the tunnel-ends, but ND over unnumbered
>tunnels should work, right? (it used to in Freebsd/kame and
>NetBSD-1.3/kame, I believe).
>If more info is necessary to figure out what's going wrong, I'd be
>happy to reproduce it and cut 'n paste some output...

	I believe the above has two issues; one is ND over tunnel, another
	is how to configure unnumbered IPv6-over-IPv4 tunnel.

	KAME does not generate ND messages to gif tunnel.  This is one of
	spec non-conformance that should be fixed.  The problem we have is
	to interoperate with other end that does not do ND, and that do ND
	with the same codebase.

	I believe you meant 'unnumbered IPv6-over-IPv4 tunnel" to say that
	"tunnel interface without global IPv6 address".  It can be configured
	like this.
	# gifconfig gif0 10.1.1.1 10.1.1.2
	# ifconfig eth0 inet6 3ffe:....	prefixlen 64 alias
	You'll need to assign global IPv6 address to the ethernet, not
	to the tunnel.  ripng will run fine over it.

	Could I know how I can repeat your symptom on "ioctl not supported..."?

itojun