Subject: Last Call: 'Teredo: Tunneling IPv6 over UDP through NATs' to Proposed Standard (fwd)

From: Pekka Savola <[email-masked]>
Date: Thu, 23 Sep 2004 20:31:04 +0300 (EEST)

FYI.

---------- Forwarded message ----------
Date: Thu, 23 Sep 2004 11:48:50 -0400
From: The IESG <[email-masked]>
Reply-To: [email-masked]
To: IETF-Announce <[email-masked]>
Subject: Last Call: 'Teredo: Tunneling IPv6 over UDP through NATs' to
    Proposed Standard 

The IESG has received a request from an individual submitter to consider the 
following document:

- 'Teredo: Tunneling IPv6 over UDP through NATs'
   <draft-huitema-v6ops-teredo-02.txt> as a Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action.  Please send any comments to the
[email-masked] or [email-masked] mailing lists by 2004-10-20.

The file can be obtained via
http://www.ietf.org/internet-drafts/draft-huitema-v6ops-teredo-02.txt

_______________________________________________
IETF-Announce mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/ietf-announce

---

From: "EricLKlein" <[email-masked]>
Date: Thu, 23 Sep 2004 22:07:35 +0200

General comment:
As IPv6 does not support NAT in any native form I would like to see the term
NAT replaced with IPv4 NAT through out the docuement, and a comment at the
start to the effect that there is no such thing as IPv6 NAT.

Speciffic comments:
Section 3.1 reads:
   The type of mappings is analyzed in [RFC3489], which distinguishes
   between "Cone NAT", "restricted cone NAT", "port restricted cone
   NAT" and "symmetric NAT". The Teredo solution ensures connectivity
   for clients located behind cone NATs, retricted cone NATs or port-
   restricted cone NATs. these three types NATs.

Some how that last three types of NATs slipped in past editing.

3.2.4 Automatic sunset
   Some how this whole section scares me as it seems to imply that there is
a way to turn an IPv4 NAT into an IPv6 Router while maintaining the NAT like
functionality. As stated above, NAT is not part of IPv6 (NAP is but is not
mentioned in this document).

Final comment:
I am also unclear why it is assumed that UDP is the prefered protocol. UDP
has no retransmits, so lost packets will stay lost while TCP has retransmit
based on acknowledgements. WHy force this on UDP?

Eric

----- Original Message ----- 
From: "Pekka Savola" <[email-masked]>
To: <[email-masked]>
Sent: 23 September, 2004 7:31 PM
Subject: Last Call: 'Teredo: Tunneling IPv6 over UDP through NATs' to
Proposed Standard (fwd)

---

From: Jeroen Massar <[email-masked]>
Date: Fri, 24 Sep 2004 08:21:58 +0200

> start to the effect that there is no such thing as IPv6 NAT.

NAT is an IPv4 only thing, there must be no IPv6 NAT, better to not name
it separately IMHO.

<SNIP>

> based on acknowledgements. WHy force this on UDP?

Because the IP protocol running inside UDP will take care of the
retransmits and if you are doing IPv6 over TCP you will need to reorder
packets, keep connections open, state etc.

Greets,
 Jeroen

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From: Pekka Savola <[email-masked]>
Date: Fri, 24 Sep 2004 09:30:15 +0300 (EEST)

> packets, keep connections open, state etc.

More precisely, if done over TCP, the results in the event of packet
loss would be catastrophic if the IPv6 packet was also TCP.  TCP over
TCP doesn't work well with packet loss.

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

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From: "Soininen Jonne (Nokia-NET/Helsinki)" <[email-masked]>
Date: Fri, 24 Sep 2004 09:36:04 +0300

> NAT is an IPv4 only thing, there must be no IPv6 NAT, better to not name

I do agree with this.

> packets, keep connections open, state etc.

In addition, there are many other implications. These include running
tcp over tcp that might produce unpredictable results, running protocol
that doesn't need/want retransmissions and would actually suffer from
retransmissions - e.g. RTP.

Cheers,

Jonne.

-- 
Jonne Soininen
Nokia

Tel: +358 40 527 46 34
E-mail: [email-masked]

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From: "EricLKlein" <[email-masked]>
Date: Fri, 24 Sep 2004 10:10:26 +0200

> From: "Jeroen Massar" > General comment:
> > NAT replaced with IPv4 NAT through out the document, and a comment at
the

This is why I think there is a need to be an explicit reference that the
need for Teredo is because NAT was depreciated in IPv6, otherwise the
question will be raised (if read without referencing this fact) as to why it
is not IPv4 NAT to IPv6 NAT.

---

From: "EricLKlein" <[email-masked]>
Date: Fri, 24 Sep 2004 10:11:15 +0200

Thank you all for clarifying my confusion about why UDP. I understand that
TCP over TCP is bad.
Eric