6to4 status (again)

[Brian E Carpenter]

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.

   Brian