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RE: FW: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
>From: Soohong Daniel Park <soohong.park@samsung.com>
>Reply-To:
>To: Elwyn Davies <elwynd@nortelnetworks.com>,
'Pyda Srisuresh' <srisuresh@yahoo.com>, Senthil Sivakumar <ssenthil@cisco.com>
>Subject: RE: FW: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
>Date:Tue, 12 Oct 2004 09:18:55 +0900
>
>RE: FW: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txtIt was not the original
goal of NAT-PT to support all of the IPv6 features.
>It is one of possible transition mechanisms althouth there are several
>restrictions originated from the traditional NAT architecture.
>
>Nevertheless, I know several sites are using NAT-PT efficiently on their use
cases.
I agree. NAT-PT is only a transiton mechanism. We use it to solve one
scenario(NAT), at last we will use the IPv6 and its new features. I don't think
restictions such as E2E should be considered more.
> Daniel (Soohong Daniel Park)
> Mobile Platform Lab. Samsung Electronics.
>
> -----Original Message-----
> From: owner-v6ops@ops.ietf.org [mailto:owner-v6ops@ops.ietf.org]On Behalf Of
Elwyn Davies
> Sent: Tuesday, October 12, 2004 2:25 AM
> To: 'Pyda Srisuresh'; Senthil Sivakumar
> Cc: 'Sham Chakravorty'; 'Brian E Carpenter'; Cedric Aoun; 'V6OPS'
> Subject: RE: FW: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
>
>
> That NAT-PT may stifle innovation is not an assumption but a deduction. As is
pointed out in the draft, NAT-PT cannot support all of the current features of v6
(eg flow labels, MIPv6) and is unlikely to support any new features. If the
NAT-PT boxes operate autonomously (without something like STUN, midcom or nsis to
help), then all applications may well have to decide to just use the subset of
features supported by NAT-PT. If they can detect that there is a NAT-PT box in
the way then special case code may be needed for destinations accessed through the
NAT-PT to limit the capabilities used.
>
> However if a proxy is used, all the special casing can be confined to the proxy
- the original application should be able to work untramelled (i.e. as if working
on a pure native v6 network when communicating with v6 addresses - v4
functionality is unchanged). Hence I think the situation as regards extra code is
exactly the reverse of what you say: applications operating with proxies can be
unaware and unchanged; applications operating through NAT-PT may need special case
coding.
>
> The lack of compelling use cases for NAT-PT indicates that it isn't an
essential mechanism. Apart from a very limited set of cases dual-stack + tunelling
solves working across multiple realms. We need to get the message out that NAT-PT
is not a good thing and that there are other, better solutions. That is the way
to overcome resistance!
>
> Regards,
> Elwyn
>
> > -----Original Message-----
> > From: Pyda Srisuresh [mailto:srisuresh@yahoo.com]
> > Sent: 11 October 2004 14:58
> > To: Senthil Sivakumar; Davies, Elwyn [HAL02:0S00:EXCH]
> > Cc: 'Sham Chakravorty'; 'Brian E Carpenter'; Aoun, Cedric
> > [ADC:7Q30:EXCH]; 'V6OPS'
> > Subject: RE: FW: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
> >
> >
> > Folks,
> >
> > As Senthil points out, the assumption that NAT-PT deployment
> > will stifle
> > innovation in v6 seems flawed. NAT-PT is a transition
> > mechanism which is
> > essential for wider V6 deployment. Without NAT-PT, you will see bigger
> > resistance to deploying V6 . You need NAT-PT for legacy
> > applications (ex:
> > e-mail, ftp) to work as is across V4 and V6 realms. No change
> > to end-hosts or
> > applications. This is the attraction of NAT-PT. This is not
> > the same as the
> > proxy solution that will require applications to be
> > changed/recompiled.
> >
> >
> > cheers,
> > suresh
> >
> >
> > --- Senthil Sivakumar <ssenthil@cisco.com> wrote:
> >
> > > At 10:16 AM 10/10/2004 +0200, Elwyn Davies wrote:
> > >
> > > >Three points:
> > > >- The object of the draft was to summarize in one place
> > all the problems
> > > >with NAT-PT rather than being yet another delta on
> > previous work. The
> > > >introduction notes that several of the points are indeed
> > generic address
> > > >translation problems. This doesn't make them any less relevant.
> > >
> > > I am fine with summarizing the issues in one draft. But the
> > draft points
> > > out those as reasons to deprecate
> > > which is what I am pointing out.
> > >
> > > >- The draft is specifically targeting the NAT-PT = SIIT +
> > DNS-ALG solution
> > > >intended for use as a generic inter-cloud translator. It
> > is clear to me
> > > >that a 'cut down' form has a use as a legacy v4 'server
> > adaptor' front end
> > > >where there is only one v4 address (or maybe a server
> > cluster) on one
> > > >side, it only has to handle a pre-defined set of
> > protocols, and it doesn't
> > > >need a DNS-ALG. I think this should be the subject of a
> > separate draft.
> > >
> > > While I agree with you the cut-down solution does not need
> > a DNS-ALG, I
> > > don't think it has to handle a
> > > specific set of protocols. I could still be a generic
> > purpose translator
> > > for facilitating transition. I am attaching
> > > a document which was one of the use case scenario we are aware of.
> > >
> > > >- The fundamental point is whether v6ops should still be
> > continuing to
> > > >support a technology which will, if widely deployed,
> > effectively stifle
> > > >innovation in v6 networks. The need for applications to
> > be aware that
> > > >NAT-PT exists effectively condemns v6 to be just v4 with
> > larger addresses
> > > >at the application level. Is this what is wanted? Or
> > should we really be
> > > >trying to put the architectural flexibility back into the Internet?
> > >
> > > I am not understanding why you say applications have to
> > aware of existence
> > > of NAT-PT.
> > >
> > >
> > > >It would be useful to see Shivkumar's use cases so that
> > they could be
> > > >considered for inclusion in the relevant transition
> > analysis. If people
> > > >are using NAT-PT in a particular way then we need to give
> > them a workable
> > > >alternative before ditching NAT-PT.
> > >
> > > Exactly. We should not prematurely deprecate the solution
> > without an
> > > alternative in place.
> > >
> > > Thnks
> > > Senthil
> > >
> > > >Regards,
> > > >Elwyn
> > > >
> > > > > -----Original Message-----
> > > > > From: Sham Chakravorty
> > > > [<mailto:schakra@mitre.org>mailto:schakra@mitre.org]
> > > > > Sent: 09 October 2004 18:35
> > > > > To: 'Brian E Carpenter'; 'Senthil Sivakumar'
> > > > > Cc: Aoun, Cedric [ADC:7Q30:EXCH]; 'V6OPS'; Davies, Elwyn
> > > > > [HAL02:0S00:EXCH]
> > > > > Subject: RE: FW: I-D
> > ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
> > > > >
> > > > >
> > > > > I agree with Shivkumar that deprecating NAT-PT really
> > doesn't earn us
> > > > > anything but removes one tool that could be used in specific
> > > > > instances.
> > > > > Application gateways are not in the same usage "level" as
> > > > > NAT-PT - they
> > > > > occur in different points of the network. Also, the
> > > > > underlying algorithm of
> > > > > SIIT would still be available.
> > > > >
> > > > > Sham
> > > > >
> > > > > -----Original Message-----
> > > > > From: owner-v6ops@ops.ietf.org
> > > > >
> > [<mailto:owner-v6ops@ops.ietf.org>mailto:owner-v6ops@ops.ietf.org] On
> > > > Behalf
> > > > > Of Brian E Carpenter
> > > > > Sent: Saturday, October 09, 2004 9:10 AM
> > > > > To: Senthil Sivakumar
> > > > > Cc: Cedric Aoun; V6OPS; Elwyn Davies
> > > > > Subject: Re: FW: I-D
> > ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
> > > > >
> > > > >
> > > > > > The point I am trying to stress is deprecating this would
> > > > > leave us with no
> > > > > workable
> > > > > > solution for communicating between IPv4 only
> > > > > networks/nodes/apps IPv6 only
> > > > > > networks/nodes/apps. As remote as it might seem for some,
> > > > > that is the use
> > > > > case
> > > > > > scenario we have encountered as the applicability of NAT-PT.
> > > > >
> > > > > But there is a workable alternative, which is an application
> > > > > level proxy.
> > > > > This too has its disadvantages, of course.
> > > > >
> > > > > Brian
> > > > >
> > > > > Senthil Sivakumar wrote:
> > > > > > I see that the draft has consolidated all the
> > previous drafts that
> > > > > > highlighted the issues
> > > > > > of NAT-PT and DNS ALG, which is a good thing.
> > However, most of the
> > > > > > issues mentioned
> > > > > > here as NAT-PT issues are known issues with address
> > > > > translation (NAT)
> > > > > > itself, so
> > > > > > attributing them to NAT-PT is not correct. Those should be
> > > > > categorized
> > > > > > as generic address
> > > > > > translation issues.
> > > > > >
> > > > > > Some specfic comments on the following issues.
> > > > > >
> > > > > > * Disruption of all protocols which embed IP
> > addresses (and/or
> > > > > > ports) in packet payloads or which apply integrity
> > > > > mechanisms
> > > > > > using IP addresses (and ports). (not NAT-PT
> > specific).
> > > > > >
> > > > > > * Requirement for applications to use keep alive
> > > > > mechanisms to
> > > > > > workaround connectivity issues caused by premature
> > > > > NAT-PT state
> > > > > > timeout. (not NAT-PT specific).
> > > > > >
> > > > > > * Inability to redirect packet fragments after the
> > > > > first with
> > > > > > NAPT-PT. (not NAT-PT specific).
> > > > > >
> > > > > > o Issues which are exacerbated by the use of a DNS-ALG:
> > > > > > * Constraints on network topology. (not NAT-PT
> > specific).
> > > > > > * Scalability concerns together with introduction of
> > > > > single point
> > > > > > of failure and security attack nexus.(not
> > NAT-PT specific).
> > > > > > * Lack of address mapping persistence: Some
> > > > > applications require
> > > > > > address retention between sessions. The user
> > > > > traffic will be
> > > > > > disrupted if a different mapping is used.
> > The use of the
> > > > > > DNS-ALG to create address mappings with limited
> > > > > lifetimes means
> > > > > > that applications must start using the address
> > > > > shortly after
> > > > > > the mapping is created, as well as keeping it
> > > > > alive once they
> > > > > > start using it.(not NAT-PT specific).
> > > > > > * Creation of a DOS threat relating to exhaustion of
> > > > > memory and
> > > > > > address/port pool resources on the
> > translator.(not NAT-PT
> > > > > > specific).
> > > > > >
> > > > > > Regarding the conclusion, I don't agree with the fact
> > that only
> > > > > > applicable scenario
> > > > > > is in 3G networks. During the past couple of years of my
> > > > > experience I
> > > > > > have seen
> > > > > > customers using it between isolated IPv6 networks to talk
> > > > > to existing
> > > > > > IPv4 networks.
> > > > > > A lot of cases it is not about the nodes being dual stack
> > > > > or not, it is
> > > > > > the network
> > > > > > that is not dual stacked for operational reasons.
> > > > > >
> > > > > > I have been gathering some inputs from the customers
> > who are using
> > > > > > NAT-PT currently
> > > > > > regarding this draft. I can consolidate and forward the
> > > > > comments if you
> > > > > > are interested in
> > > > > > knowing and understanding why they think they are moving
> > > > > forward with
> > > > > > NAT-PT.
> > > > > >
> > > > > > The point I am trying to stress is deprecating this would
> > > > > leave us with
> > > > > > no workable
> > > > > > solution for communicating between IPv4 only
> > > > > networks/nodes/apps IPv6 only
> > > > > > networks/nodes/apps. As remote as it might seem for some,
> > > > > that is the
> > > > > > use case
> > > > > > scenario we have encountered as the applicability of NAT-PT.
> > > > > >
> > > > > > Senthil
> > > > > >
> > > > > > At 10:12 AM 9/22/2004 +0200, Cedric Aoun wrote:
> > > > > >
> > > > > >> Hi,
> > > > > >> As discussed at IETF 60, the WG agreed to continue the NAT-PT
> > > > > >> deprecation analysis.
> > > > > >> We would really appreciate if you could provide us your
> > > > > feedback on
> > > > > >> the initial version of the deprecation analysis by Monday
> > > > > October 4th.
> > > > > >> Regards
> > > > > >> Cedric Aoun
> > > > > >> ------ Forwarded Message
> > > > > >> From: <Internet-Drafts@ietf.org>
> > > > > >> Reply-To: <internet-drafts@ietf.org>
> > > > > >> Date: Tue, 21 Sep 2004 21:38:33 +0200
> > > > > >> To: <i-d-announce@ietf.org>
> > > > > >> Subject: I-D ACTION:draft-aoun-v6ops-natpt-deprecate-00.txt
> > > > > >>
> > > > > >> A New Internet-Draft is available from the on-line
> > Internet-Drafts
> > > > > >> directories.
> > > > > >>
> > > > > >>
> > > > > >>
> > > > > >> Title : Reasons to Deprecate NAT-PT
> > > > > >> Author(s) : C. Aoun, E. Davies
> > > > > >> Filename :
> > draft-aoun-v6ops-natpt-deprecate-00.txt
> > > > > >> Pages : 24
> > > > > >> Date : 2004-9-21
> > > > > >>
> > > > > >> This document discusses reasons why use of the
> > specific form of
> > > > > >> IPv6-IPv4 protocol translation mechanism implemented by
> > > > > the Network
> > > > > >> Address Translator - Protocol Translator (NAT-PT)
> > > > > defined in RFC 2766
> > > > > >> should be deprecated and RFC2766 moved to historic status.
> > > > > >> Description of an alternative protocol translation
> > > > > mechanism is out
> > > > > >> of scope for this document.
> > > > > >>
> > > > > >> A URL for this Internet-Draft is:
> > > > > >>
> > > > >
> > > >
> > >
> > <<http://www.ietf.org/internet-drafts/draft-aoun-v6ops-natpt-d
> > e>http://www.ietf.org/internet-drafts/draft-aoun-v6ops-natpt-de
> > >
> > > >
> > > > > precate-00.txt
> > > > >
> > ><http://www.ietf.org/internet-drafts/draft-aoun-v6ops-natpt-d
> > e>http://w
> > > > ww.ietf.org/internet-drafts/draft-aoun-v6ops-natpt-de
> > > > > precate-00.txt
> > > > >
> > > > > >>
> > > > > >>
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> > > >
> > >
> >
> > > ATTACHMENT part 2 application/msword name=nat-pt-scenario.doc;
> > x-mac-type=42494E41; x-mac-creator=4D535744
> >
> >
> >
> > =====
> >
> >
> >