Microsoft: Give Xbox One users IPv6 connectivity

[Jakob Hirsch]

On 14.03.2014 12:47, Tore Anderson wrote:
>>> Christopher and others => you are RIGHT! Do not change your mind
>> Right abouth _what_? You provided not a single reason for the described
>> behaviour, i.e. the missing fallback to native IPv6.
> According to Microsoft, there should never be a "fallback to native
> IPv6", as IPv6 should be the preferred protocol. Teredo should be the
> fallback, for those situations where end-to-end IPv6 isn't available.

The "fallback" I was talking about is not a description of the current
behaviour, it's about what is missing.

> Can you confirm that this is the case that all the XB1s involved have
> native IPv6 connectivity, and that Teredo is used in spite of that? (If

No, and I did not claim that.

> not all of the XB1s communicating have native IPv6, fallback to Teredo
> is the expected behaviour.)

"documented", yes, but sureley not "expected".

> involved XB1s are behind AVM HGWs, any IPv6 connectivity is broken and
> thus useless. That may well be the reason why the XB1 is trying to fall
> back on Teredo in the first place, a fact that makes the claims in the

No, according to Microsoft the XB1 will not use native IPv6 if one of
the peers is IPv4 only.

> «The Xbox's behavior contradicts the Teredo standard (RFC 4380 Section
> 5.5)». --> No, it doesn't, because the XB1 *doesn't* have IPv6
> connectivity, because the AVM broke it.

No. Just because there's stateful IPv6 firewall does not mean "no IPv6
connectivity"?

> (Besides which, RFC 4380 section
> 5.5 is meant for Teredo implementers, not for HGW manufacturers.)

So what? It's XB1 which is using Teredo and violating section 5.5 of RFC
4380 (which is, ironically, authored by Microsoft itself). And now the
HGW is the one to blame for that it was not expecting that?

> Finally, the KB article says «there is a risk that using Teredo could
> allow the security functions of the FRITZ!Box to be circumvented». I
> cannot see how the presence of IPv6 makes this any worse. If AVM had

That's simple:
- As long as my HGW is _not_ doing IPv6, I do not expect it to prevent
unwanted IPv6 traffic
- If my HGW _is_ doing IPv6, I do expect it to prevent unwanted IPv6 traffic

Sure, this is all debatable and everything, but I really don't
understand the harsh bashing of AVM and avid defense of the XB1 at the
same time time here. The XB1, as recently released device, abuses an
outdated, skunky protocol to create its own pseudo-VPN and everybody's
cheering for it, without a single critical remark? That's just sad.