commit 6eee2ca426bb45faf3b53b481dea956aaecc7dbf Author: teor teor@torproject.org Date: Thu Jan 30 08:29:51 2020 +1000

Prop 311: Avoid depending on exact extend details

We don't want to depend on extends preferring IPv4 or IPv6, or the exact extend implementation, if we don't have to.

Part of 24404. --- proposals/311-relay-ipv6-reachability.txt | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/proposals/311-relay-ipv6-reachability.txt b/proposals/311-relay-ipv6-reachability.txt index d2f6b70..ace1704 100644 --- a/proposals/311-relay-ipv6-reachability.txt +++ b/proposals/311-relay-ipv6-reachability.txt @@ -213,6 +213,14 @@ Ticket: #24404 way, and lets us migrate from the current behavior to the 3.3.1 behavior down the road.

+ However, it might not be necessary: clients should not care if their + extends are over IPv4 or IPv6, they just want to get to an exit safely. + (And clients should not depend on using IPv4 or IPv6, because relays may + use an existing authenticated connection to extend.) The only use case + where extends might want to prefer IPv4 or IPv6 is relay reachability + tests. But we want our reachability test design to succeed, without + depending on the specific extend implementation. + 3.4. Rejected Extend Designs

Some designs may never be suitable for the Tor network.