6to4 status (again)

[Brian E Carpenter]

> XP didn't have IPv6 enabled by default, and IIRC didn't have Teredo even if you enabled IPv6? 

I think the default depended where your image came from. XP definitely had
Teredo (and so did Vista of course, but I think its defaults were like Win7).

It almost doesn't matter, though. People here are reporting substantial
amounts of 6to4 traffic, from clients not under their control, so whether
they are XP, Airports or whatever doesn't really make any difference:
the key thing is that they are clients not under the 6to4 relay operators'
control. So people have to either handle the traffic or drop the traffic;
stopping it at source is not an option.

Regards
   Brian

On 01/03/2013 15:45, Phil Mayers wrote:
> On 01/03/13 15:40, Brian E Carpenter wrote:
>> On 01/03/2013 14:58, Ignatios Souvatzis wrote:
>>> On Fri, Mar 01, 2013 at 02:04:50PM +0000, Brian E Carpenter wrote:
>>>
>>>> You can't fix legacy clients and CE devices, that's the problem. If
>>>> they are
>>>> young enough to have v6 enabled by default, but old enough to have
>>>> anycast 6to4
>>>> enabled by default and v6 always preferred, they will try 6to4 and
>>>> will not fall
>>>> back to v4.
>>>>
>>>> (The story is similar for Teredo.)
>>>
>>> Shouldn't - Teredo is explicitly specified to be last-resort, IIRC.
>>> Do the prevalent implementations disagree?
>>
>> As I understand the RFC3484 default, which would apply to legacy
>> systems, if there's a Teredo address it will beat IPv4. I don't
>> know if the older Windows stacks actually do that, personally.
> 
> Any version of windows with Teredo has it de-prefed IIRC; my Win7 box has:
> 
> netsh interface ipv6>show pref
> Querying active state...
> 
> Precedence  Label  Prefix
> ----------  -----  -------------
>         50      0  ::1/128
>         40      1  ::/0
>         30      2  2002::/16
>         20      3  ::/96
>         10      4  ::ffff:0:0/96
>          5      5  2001::/32
> 
> 
> XP didn't have IPv6 enabled by default, and IIRC didn't have Teredo even
> if you enabled IPv6?
>