O1.1 - Propose and implement IPv6 ORPort reachability checks on relays
See Proposal 311: Tor Relay IPv6 Reachability: https://gitweb.torproject.org/torspec.git/tree/proposals/311-relay-ipv6-reachability.txt
The child tickets are in proposal section order, but they will probably be implemented in this order:
Pre-Implementation Improvements:
- Require IPv6 tests in Travis CI (O1.3, #33195 (moved))
- Test IPv4 Reachability using Chutney (O1.3, #33232 (moved))
Implementation:
- Allow Relay IPv6 Extends
- Declare Support for Subprotocol Version "Relay=3"
- Check Relay and Bridge IPv6 ORPort Reachability
Internal Testing:
- Test IPv6 ORPort Reachability using Chutney (O1.3, #33228 (moved))
- Test Legacy Relays Accept IPv6 Extends using Chutney (O1.3, #33231 (moved))
Public Tor Network Testing:
- Test IPv6 ORPort Reachability on the Tor Network
- Ask Relay Operators to Test IPv6 Reachability