Teredo sunset - did it happen?

[Christopher Palmer]

We (Microsoft) has a standing plan to deactivate our public Teredo servers, which would essentially deactivate the default Teredo functionality in the Windows user base. We had thought to do that next year, but delayed for various reasons - one being that the pain/noise around it's default activation on Windows devices has abated considerably over time.

The deactivation of our public Teredo service is not the same thing as "sunsetting Teredo" or deprecating the protocol entirely. It will still be used by the Xbox Live gaming stack and we strongly desire for network operators to continue to treat Teredo as a legitimate NAT traversal and IPv6 transition technology. Other uses of Teredo beyond gaming are being considered.


-----Original Message-----
From: ipv6-ops-bounces+christopher.palmer=microsoft.com at lists.cluenet.de [mailto:ipv6-ops-bounces+christopher.palmer=microsoft.com at lists.cluenet.de] On Behalf Of Brian E Carpenter
Sent: Monday, November 17, 2014 4:11 PM
To: Phil Mayers
Cc: IPv6 Ops list
Subject: Re: Teredo sunset - did it happen?

I said:

> But if the client has the old RFC 3483 policy table,
> ::ffff:0:0/96 has the lowest precedence so Teredo would win over IPv4, 
> which is a Bad Thing. There isn't much to be done about that unless 
> the user has netsh skills.

s/3483/3484/

  Brian

On 18/11/2014 13:01, Brian E Carpenter wrote:
> On 18/11/2014 07:12, Phil Mayers wrote:
>> On 17/11/2014 17:43, Darren Pilgrim wrote:
>>
>>>> Any ideas what's going on? Microsoft, anyone care to comment?
>>> Microsoft released an Windows Update for the prefix policy table.  
>>> The update dropped Teredo's precedence to lower than IPv4.
>> Just to be clear - are you suggesting they did this instead of 
>> sunsetting Teredo altogether?
>>
>> In any case, I was always under the impression this was the day-one 
>> experience - Teredo would only be used to talk to another Teredo DNS 
>> name or an IPv6-only name in the absence of native IPv6. Am I mistaken?
> 
> I think that was always the intention, but unmanaged tunnels are 
> liable to behave undesirably. From what Dave Thaler said during the 
> discussion at the IETF last week on deprecating 6to4, MS clearly sees 
> Teredo for Xbox-to-Xbox as operational and Teredo for regular 
> client/server use as undesirable, same as you do.
> Dave therefore wanted no change to the RFC 6724 default policy table, 
> which I assume is exactly what Windows now ships.
> 
> Then, even if the Teredo interface comes up, since
> ::ffff:0:0/96 has higher precedence than 2001::/32, Teredo will not be 
> tried unless there is no IPv4 address at all for the target host.
> 
> But if the client has the old RFC 3483 policy table,
> ::ffff:0:0/96 has the lowest precedence so Teredo would win over IPv4, 
> which is a Bad Thing. There isn't much to be done about that unless 
> the user has netsh skills.
> 
>     Brian
>