On 19/07/2013 22:15, Tim Chown wrote: > On 19 Jul 2013, at 10:34, Phil Mayers <[email protected]> wrote: > >> On 07/18/2013 09:09 PM, Brian E Carpenter wrote: >> >>> Wait... I had the impression that iff there was no other IPv6 connectivity, >>> Teredo was used in older Windows because of the generic "prefer IPv6" rule. >>> The default RFC 3484 table covers 6to4 but not Teredo. >> AFAIK, every version of windows (i.e. Vista, 7, 8) that comes with Teredo >> also comes with a de-pref rule for it, not just "recent" versions. >> >> Put another way, Teredo should never be preferred over IPv4, because all >> versions of Windows with Teredo use extended RFC 3484 rules. >> >> Most of the Teredo activity we see is when IP addresses are used directly >> (i.e. no getaddrinfo). For example, BitTorrent connections where peers were >> looked up in DHT/PEX. In these cases, an IPv6 address will be connected to >> over Teredo if there's no other connectivity. > > Again, my understanding is the same as Phil's here.
I think my recollection is of Teredo with Windows XP SP2. But I could be wrong, of course. In any case, the case for phasing out Teredo is strong, like the case for disabling client-side 6to4. Brian > Many vendors/implementors started adding rules that ultimately appeared in > RFC6724 long before RFC6724 was published. It took 6 years(!) for that > update to be completed through the IETF. > > There are however some platforms stuck on 3484 or that don't follow such > rules (Mac OSX is an interesting one...) > > Tim > >
