RE: automatic tunneling and v6 interoperation

[Pekka Savola <pekkas@netcore.fi>]

On Thu, 13 Nov 2003, Christian Huitema wrote:
[on the traffic from Teredo host to {native,6to4}]
> The hypothesis is that the relay is close to the "native host". During
> the transition period, the native ISP have an interest in providing a
> relay service for use by their native subscribers. Their subscribers
> will enjoy better connectivity, i.e. will be happier. Providing the
> service does not result in extra bandwidth requirement: the packets are
> exchanged between your subscribers and the Internet; they are simply
> using a v6-v4 path instead of a v6-v6 path.

Could you describe how the Teredo host finds this relay (close to the 
native host)?  Note that I was not describing the traffic from the native 
host to a Teredo host.

> > 2) the implication of "no relays" deployment to v6 interoperability
> > 
> > If there are no relays, note that every node a Teredo host needs to
> > communicate with has to implement and enable Teredo, as well as
> publicize
> > the Teredo addresses in the DNS in addition to the others, correct?
> 
> They don't actually publish a Teredo address. I showed you Tuesday the
> result of "ipconfig" on my XP laptop: I have public addresses associated
> to the wireless interface, using the 2001:468:19ff:80::/64 prefix
> announced on the IETF network; the Teredo interface is available for use
> as a local relay, but only documents a link-local address on that
> interface. (And we do not advertise link local addresses in the DNS).

Again, the local relay onyl addresses the communication from native -> 
Teredo direction -- what about the other direction?  Where are the relays, 
and if not, the address needs to be in the DNS, right?
 
> > So, I don't think Teredo (or 6to4 for that matter, but it's slightly
> > better from the second perspective) really solves the "economics of
> > providing IPv6 service" -problem.  The only thing it seems to solve,
> to an
> > extent, is a relatively smooth and direct IPv6 connectivity between
> Teredo
> > hosts.  On the other hand, speaking to any other kind of nodes (e.g.,
> > 6to4, native, ...) is riddled with identical problems as the IPv6
> > deployment at ISPs.
> 
> See above. The trick is that the relays are deployed by other ISPS, for
> the benefits of their own customers.

No, this addresses (to some degree) only the other direction.  What about 
those who sit behind an ISP who doesn't care about v6? 
 
> An IPv6 ISP that really wants to isolate its customers from the Teredo
> technology can do that by providing native connectivity and a Teredo
> relay (not a server). The ISP's customers will not need to implement
> their own relay.

Again, what about the Teredo hosts which have no such relays?

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings