On Sun, Apr 03, 2005 at 12:53:37PM +0200, Ignatios Souvatzis wrote:
> Just a remark:
> 
> On Sun, Apr 03, 2005 at 12:37:02PM +0200, Hubert Feyrer wrote:
> 
> > Looking at Toredo[1] it seemt to tunnel the v6 pkgs similar to 6to4, but 
> > uses a NAT-friendlier encapsulation (v4 UDP instead of some non-IP 
> > protocol, that's unlikely to be handled by NAT).
> 
> both 6to4 and fixed IPv6 in IPv4 tunnels use IP protocols... just neither
> TCP nor UDP.
> 
> Unless the hardware is deployed already, the less hacky solution would be
> to get an el cheapo embedded 486/586/arm box, add some NetBSD, ipf for the
> NATing, and whatever IPv6 tunnel endpoint you need, and be done with it.
> 
> Alas, I understand David's NAT boxen are already installed at his customers'
> sites.

I provide the customer a wireless IPv4/IPv6 router that goes on
their chimney.  My colleague Sascha made a photo-illustrated guide to
construction and installation, <http://cuwireless.net/node_setup.html>.
The wireless "rooftop routers" create a mesh over the neighborhood.
See <http://www.freepress.net/wifi/guideintro.php> for an overview.
Each rooftop router has an ethernet "tail" that goes into the house.

Oftentimes the customer has a wireless home gateway that does NAT & DHCP.
If not, we sometimes recommend that they buy one.  The customer plugs
the rooftop router's "tail" into the home gateway.

The rooftop router auto-detects an Internet connection on its ethernet
tail.  If it gets a DHCP lease w/ IP gateway, it assumes that it is
Internet-connected and advertises a default route on the wireless mesh.
If it does not get such a lease, it turns into a DHCP server itself;
it issues DHCP leases on its tail, indicating it is an Internet gateway.

We cannot afford to buy home gateways for our "customers" (they are
not paying customers, yet---this a research testbed, not a business).
Configuring customers' home gateways to suit me is inconvenient for
both the customer and I: they may not remember their admin password,
they may prefer their own custom configuration to mine, I have to figure
out how to configure a dozen different models.  I want for this network
to be easy to reproduce by others, even amateurs, and reconfiguring home
gateways adds elements of uncertainty and complexity I would rather avoid.
I want to avoid reconfiguring home gateways if I can help it.

So that my team can troubleshoot the mesh from our office, so that
researchers at the local university can log-in and run experiments, and
so that we can experiment with IPv6 to the home, I need for all of the
Internet-connected rooftop routers to be reachable by known IP numbers.
We have one server with a fixed IPv4 number that can terminate tunnels,
act as a Teredo server/relay, etc.  With very little work, I can set it
up for 6to4, also.

I hope that you understand now what I am trying to achieve.

Dave

-- 
David Young             OJC Technologies
dyoung@ojctech.com      Urbana, IL * (217) 278-3933