Re: Tunneling ipv6 over gif

["Steven M. Bellovin" <smb%bellovin.org@localhost>]

On Mon, 29 Jun 2009 15:37:47 -0400
Greg Troxel <gdt%ir.bbn.com@localhost> wrote:

> 
> "Steven M. Bellovin" <smb%bellovin.org@localhost> writes:
> 
> > I'm trying to set up a tunnel from a NetBSD machine to a Cisco
> > router. The goal is to carry v6 traffic.  Ultimately, the NetBSD
> > machine will be a router; for the moment, though, I'm just trying
> > to get the point-to-point stuff working.  
> >
> > Following gif(4), I've done
> >
> >     ifconfig gif0 create
> >     ifconfig gif0 myV4addr theirV4addr up
> >     ifconfig gif0 tunnel inet6 myV6addr theirV6addr
> >
> > Ifconfig shows that correctly, though it doesn't show anything in
> > the v6 routing table for the v6 addresses.
> 
> That's a tunnel with v6 outer addresses carrying v4, which will be
> useful for the legacy 4bone after ISPs stop carrying v4 traffic in
> 2015.
> 
> Seriously, I think you want to put the v4 addresses with 'tunnel', and
> the v6 without, so that your outer addresses are v4 and v6 packets
> carried within.

That will do it...  I'll meditate on a correction to the man page,
which I think is wrong; it shows

        ifconfig gifN A netmask 0xffffffff tunnel A D up

i.e., reusing A.

Thanks.