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. 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
