Re: IPv6 routing /48s

[Florian Weimer <fw () deneb enyo de>]

* Mohacsi Janos:

> On Thu, 20 Nov 2008, Nathan Ward wrote:
>
> > On 20/11/2008, at 4:06 AM, Florian Weimer wrote:
> >
> > > * Michael Sinatra:
> > >
> > > > And it just reinforces the fear that people have against putting AAAA
> > > > records in DNS for their publicly-accessible resources, especially
> > > > www.
> > >
> > > Won't current Windows clients work just fine in this case?
> > >
> > > I have no idea what a fix should look like for some of the non-Windows
> > > systems I care about, unfortunately.

Do you mean that the client tries to enable 6to4 unsuccessfully?

> > No, unfortunately broken 6to4 auto-configuration (ie, in Vista,
> > XPSP2, when on a non-RFC1918 IP address) breaks, and you get 90s
> > timeouts before falling back to IPv4/A.
>
> This must be a broken RFC 3484 implementation:
> - 6to4 should be less prerefed than IPv4 if the service has both AAAA
> and A record.

RFC 3848 generally prefers IPv6 over IPv4 and fails if the host
running its algorithm has neither IPv6 connectivity nore mean to
detect that efficiently.  I think Windows does something in the second
area.