Re: REVIEW NEEDED: draft-durand-v6ops-assisted-tunneling-requirements-00.txt

[Pekka Savola <pekkas@netcore.fi>]

On Wed, 5 May 2004, JORDI PALET MARTINEZ wrote:
> That's true if both hosts try to use the same Tunnel server.

Obviously, as we want to implement a discovery protocol, these would 
almost always be the same.

> But I also believe that when there are several host behind a NAT, or
> in the same LAN, is more interesting to use proto-41 or any other
> mechanism to provide a single prefix to all the LAN. It provides a
> lot of advantages.

Obviously, but may be non-trivial to set up, and might not be 
supported at all by the non-registered mode (if it only provided a 
/128, which would remain to be seen).

> It should not be very difficult, as part of the implementation of
> the tunneling protocol (TSP or whatever), detect this situation
> automatically and even configure one of the host as "router" for the
> rest of the network.

Actually, I would argue that this _would_ be very challenging.  Note
that the NAT may be done by the operator as well, not just the user.  
It would be simpler to try to figure out whether there are other v6
nodes behind the same NAT, but that's deep magic and failure-prone as
well.

Proto-41 forwarding seems work within certain specific scenarios
(i.e., the only NAT is done by the customer's CPE, a host would be
willing to serve as an IPv6 router, and that a prefix delegation is
available), but it doesn't seem to be possible to generalize its
detection and use for the protocol.

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