How to report IPv6 bug to Microsoft - Vista and 7 won't "undeprecate" a prefix

[Ole Troan]

Mark,

>>> A number of our customers are having trouble with IPv6 under Windows Vista and 7 on our IPv6 trial.
>>> 
>>> Currently we are giving customers a static delegated prefix via DHCPv6-PD (a /60 currently). When they have an ADSL drop out, some IPv6 CPE is deprecating the assigned LAN interface global /64 prefix by sending an RA with a zero second preferred lifetime for the prefix. Windows Vista and 7 are quite correctly labelling the prefix as deprecated, as it still has a non-zero valid lifetime. Deprecating the prefix at this time makes sense as there is a possibility that the delegated prefix may not be re-assigned to the CPE after the ADSL link is restored, and may be re-assigned by the ISP to another customer. This is also the behavior specified in the recently published RFC6204, "Basic Requirements for IPv6 Customer Edge Routers".
>> 
>> no, it isn't.
>> this behaviour breaks local communication within the home.
>> 
> 
> Hmm. Well that's the behavior this CPE seems to be exhibiting. I think I've been fooled a bit by misremembering this clause from the RFC -

not one of ours? if so let me know.

> 
>   L-13:  If the delegated prefix changes, i.e., the current prefix is
>          replaced with a new prefix without any overlapping time
>          period, then the IPv6 CE router MUST immediately advertise the
>          old prefix with a Preferred Lifetime of zero and a Valid
>          Lifetime of the lower of the current Valid Lifetime and 2
>          hours (which must be decremented in real time) in a Router
>          Advertisement message as described in Section 5.5.3, (e) of
>          [RFC4862].
> 
> 
> However, I don't think that means that Vista and Windows 7 doesn't have a bug though. Surely it is valid for a prefix to be "undeprecated"?

absolutely. didn't mean to create any doubt that that is a bug.

cheers,
Ole