On Tuesday 08 November 2005 02:54 pm, Steven M. Bellovin wrote:
> my home network and connect them to my cable modem.  (The cable modem
> has its own NAT function.)  That's fine for v4; however, I'd like to
> pick up v6 packets there and tunnel them somewhere via 6to4.  I suspect
> that it isn't possible to do that; I'd be happy to find out I'm wrong.

That may prove difficult if you're using the modem's NAT. 6to4 requires the 
machine doing the 6to4 tunneling to have a public IPv4 address. Additionally 
most static tunnels (Hexago's being one exception (but not for NetBSD)) won't 
work because most consumer NAT boxes don't have an interface to allows 
protocol forwarding (in this case 41). This leaves you with Teredo which uses 
IPv4 UDP to traverse NAT, however there is no implementation for NetBSD.

If the modem uses PPPoE for the upstream connection and can do PPPoE bridging, 
you could use pppoe(4) to give your NetBSD box the IP.

	Jonathan Kollasch