Subject: POLL: Consensus for moving forward with Teredo?

From: Pekka Savola <[email-masked]>
Date: Fri, 30 Apr 2004 20:32:26 +0300 (EEST)

Hi,

(co-chair hat on)

As identified in the scenarios analysis at IETF59 and in
draft-savola-v6ops-tunneling-01.txt, there appears to a need which
cannot be filled by another mechanism for Teredo at least in one major
Unmanaged scenario.

Is there rough consensus to move forward with Teredo? (i.e., to adopt
it as WG document in this WG or elsewhere, for Proposed Standard.)

The main issue raised has been to call for a more extensive analysis
for the deployment implications of native, 6to4, and Teredo.  There is
already discussion of this in the Unmanaged Analysis document.  There
seemed to be very little energy or interest in the WG to drive this
much further.

The options regarrding Teredo at this stage seem to be:

 a) Go forward with Teredo, hone the deployment implications in the 
    unmanaged analysis in parallel (if and as appropriate),

 b) Conclude that there is no sufficiently strong need for Teredo, and 
    not support its advancement (for PS) at this stage, or

 c) Decide that we need to analyze the scenarios or deployment more 
    before being able to make a decision.  

    If so, please state where you believe more analysis is needed.. 
    and volunteer if possible :)

If you have an opinion, please state it within a week, i.e., by next
Friday, 7th May.

Thanks!

(co-chair hat off)

---

From: Marc Blanchet <[email-masked]>
Date: Fri, 30 Apr 2004 15:26:14 -0400

b) 
because: 
- there are other ways on the table to do nat-traversal.
- teredo introduces many security issues, such as very open relays that are
subject to be used for large scale DDOS
- teredo is complex to implement
- teredo introduces states and buffering in relays when the first packets
are sent, which have important issues in implementing.
- teredo does not work for symmetric NATs and the "fallback" for a user in
this situation is "no service".

Marc.

> If you have an opinion, please state it within a week, i.e., by next

------------------------------------------
Marc Blanchet
Hexago
tel: +1-418-266-5533x225
------------------------------------------
http://www.freenet6.net: IPv6 connectivity
------------------------------------------

---

From: Ole Troan <[email-masked]>
Date: Fri, 30 Apr 2004 21:31:01 +0100

>     and volunteer if possible :)

b). what Marc said.

/ot

---

From: Pekka Savola <[email-masked]>
Date: Fri, 30 Apr 2004 23:47:39 +0300 (EEST)

As for my personal view, it's a).

Reasons for this are:
 - other, simpler ways will be specified that will be able to do NAT 
   traversal and provide connectivity in the scenario where your ISP 
   would be willing to provide a tunnel.  I.e., Teredo only needs to 
   solve the scenario where you have no ISP to get v6
   connectivity.
 - it's already out there by the million, and the only economically 
   feasible way to bring the IPv6 to the masses i.e. bring out the 
   IPv6-only applications without which we'll have very hard time
   getting IPv6 _really_ there.   Waiting for all the ISPs in the 
   world to deploy v6 before there is clear market demand isn't going 
   to cut it.  The chicken-and-egg problem must be tackled somehow, 
   and this provides a means to do that.
 - current Teredo specification is reasonably secure, in practice
   performing a "return routability check"; much better than 6to4 in 
   any case, and comparable or higher than many others we have.
 - the analysis on the deployment tradeoffs is already far along to 
   be able to say that we will have to pay the "cost" for dealing 
   with {native,6to4,Teredo} in any case.

---

From: "Tony Hain" <[email-masked]>
Date: Fri, 30 Apr 2004 15:31:32 -0700

a)  - it complements 6to4 for the case where a NAT is in the path, as it is
equally trivial for consumers to use. 

The other technologies we have on the table also need to be progressed to PS
so the market can sort out which of them it really wants. The IETF fails
when it tries to dictate deployment approaches to the market. 

Tony

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf
> Of Pekka Savola
> Sent: Friday, April 30, 2004 10:32 AM
> To: [email-masked]
> Subject: POLL: Consensus for moving forward with Teredo?
> 
> Hi,
> 
> (co-chair hat on)
>

---

From: Alain Durand <[email-masked]>
Date: Fri, 30 Apr 2004 15:59:46 -0700

>     and volunteer if possible :)

There is an alternative:

d) publish it as Experimental.

There is code out there, deployable by the millions,
so it is good to document it formally. However, for the reasons Marc 
gave, I'm not
convinced that PS is the right approach.
Actually, I would suggest that Isatap be published as Experimental 
along Terredo,
for the same reasons.

	- Alain.