Re: v6 deployment in general [Re: tunnel broker deployment [RE: Tunneling scenarios and mechanisms evaluation]]

[Pekka Savola <pekkas@netcore.fi>]

On Tue, 16 Mar 2004, Erik Nordmark wrote:
> > The problem is worse with transition mechanisms, especially the ones 
> > which traverse NATs, but the situation may improve as soon as we can 
> > get rid of them.  In any case, such mechanisms can provide a stable 
> > as long as they can keep the NAT/IP mappings stable -- which is, for a 
> > properly designed application, maybe sufficient.
> 
> I guess I don't understand what "such mechanisms" refer to above.
> I don't know if mechanisms like Teredo can provide a stable IPv6 address 
> when the nat mappings change, but doing TB/UDP for nat traversal should be
> able to provide stable IP addresses/prefixes in this case.

The point is to keep the NAT (etc.) mappings open as long as possible
so that they don't change -- and if they change, that'd be due to ISP
trying to enforce the user to a specific policy (e.g., changing v4
addesses on the fly) -- and I'm not sure if it's worth trying to
outsmart ISPs.  Stupidity always wins, with the customer in even a
bigger mess in the end.. :-/

As for what Christian said about Teredo reacting to these on-the-fly
address changes -- the spec says nothing of the sort, but may be of
course done by the implementation.  Might not hurt to add some text on
that specific case.

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