RE: FW: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt

["Zhenyu Wu" <y030729@njupt.edu.cn>]

We are all talking about wheather the NAT-PT should be chosen. But there are lots
of transimisms besides NAT-PT, do you think they are all helpful to a special
circumstance? A special transition mechanism solves a special condition, if there
a mechanism that can replace NAT-PT much better, we can consider to deprecate it.

Best,

>From: Senthil Sivakumar <ssenthil@cisco.com>
>Reply-To: 
>To: Pekka Savola <pekkas@netcore.fi>
>Subject: RE: FW: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
>Date:Thu, 14 Oct 2004 15:09:08 -0700
>
>At 08:12 PM 10/14/2004 +0300, Pekka Savola wrote:
> >On Tue, 12 Oct 2004, Pyda Srisuresh wrote:
> > > >                     If that's not the case, it's certainly not
> > > > correct -- you can deploy IPv6 as dual-stack without any need for
> > > > NAT-PT.  And dual-stack is definitely the simplest way to deploy IPv6.
> > >
> > > [suresh] You might refer comments from Steve Klynsma & Jim Bound - about
> > > difficulties the defence dept faces to transition to dual stacks. It 
> > just goes
> > > to show that the IETF can only offer transition mechanims, but not 
> > mandate one.
> > > When the choices are comprehensive, the customers will pick the one 
> > that best
> > > suits their environment.
> >
> >Such networks are likely to require something like tunneling or
> >translation, yes.  But the real problem with NAT-PT is that all the
> >people who don't need it, and shouldn't need it were they to deploy
> >IPv6 as dual-stack, want to try to fit it in their deployment plans
> >because, "well, it exists.. so there must be some use for it for us
> >here".
> 
> We all agree that NAT-PT should not be used when it does not have to be
> and I think there are enough documents out there to describe all the
> issues with NAT-PT.  But we should not discount the fact that there
> are use case scenarios and this is a real life use case scenarios.
> 
> 
> 
> >NAT-PT like translation needs to be the last choice, not to dictate or
> >give inappropriate direction to the deployment.
> 
> Nevertheless, it has to be a choice. Most of the people agree that it is the
> last choice.
> 
> Senthil
> 
> > > > I have the feeling that most typical applications applications already
> > > > support proxies or have inherent support for middleboxes (e.g., http,
> > > > smtp, dns, ftp).
> > >
> > > [suresh] Disagree with your comment about proxies. What did you mean by
> > > "inherent support for middleboxes"? Middleboxes refer to many things 
> > including
> > > proxies, NATs and NAT-PTs.
> >
> >Web proxies are common.  FTP proxies are common.  Mail submission (a
> >function of SMTP) is submitted to a 'proxy'.  DNS lookups are usually
> >done from a recursive name server.
> >
> >Lots of protocols are already using explicit middleboxes such as
> >recursive DNS servers, web proxies, etc. -- that's a good thing.
> >Leveraging these for transition makes great deal of sense.
> >
> >NAT-PT (and NAT) try to act as a middlebox transparently, without the
> >consent of the host or the application.  This causes a lot of
> >problems.  Explicit middleboxes, above, do not have this problem.
> >
> >--
> >Pekka Savola                 "You each name yourselves king, yet the
> >Netcore Oy                    kingdom bleeds."
> >Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
> 
> 
>