On 12.08.2019 23:39, teor wrote:

On 13 Aug 2019, at 05:08, Roman Mamedov <rm@romanrm.net> wrote:

On Mon, 12 Aug 2019 00:46:50 +0000
Christopher Sheats <yawnbox@emeraldonion.org> wrote:

Tor Project, please increase your #IPv6 awareness/outreach similar to how

ARIN and the other RIRs try very hard to do.

Before outreach Tor would need some actual IPv6 support, as in using it for
the actual traffic of relay-to-relay communication. I tried running a few
relays with very fast IPv6 and slow IPv4 (due to a common NAT frontend which
was the bottleneck), but it was a complete nonstarter.

Tor relays currently don't connect over IPv6. When 10% of the network

supported IPv6, there wasn't much point, because putting a very small

number of paths over IPv6 has privacy risks. So we focused on client, guard,

and exit IPv6 support.

But currently, about 30% of the consensus weight supports IPv6. So we

are working on a grant for IPv6 support (see below).

We won't be able to prefer IPv6 until 50-67% of relays support IPv6, for

load-balancing and privacy reasons. But we plan on using the

"Happy Eyeballs" (RFC 8305) algorithm on dual-stack relays. So

sufficiently slow IPv4 will cause relays to connect over IPv6. (And we can

tune the load-balancing using the IPv4 to IPv6 delay.)

I still would say that these stats are deeply flawed. Looking at the Autonomous Systems where the relays are located from the top100, 99 of them do support IPv6 (85,7625% consensus weight), the only one which doesn't support is AS4224 but since they manage their AS themselves they would only need to ask their LIR and would get IPv6.