Public bug reported: On Ubuntu xenial, systemd starts Tor before the IPv6 address is available and so Tor fails to assign an IPv6 address then exits. systemd tries to restart Tor (I think five times) but even by the last time there's still no IPv6 address assigned and hence Tor fails to start.
As a work-around I added RestartSec=10 to the systemd unit file to slow down the restart such that by the second time tor starts, there is an IPv6 address available. See discussion here for more details https://trac.torproject.org/projects/tor/ticket/25182 ** Affects: tor (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1749309 Title: Tor starts before IPv6 is available To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/tor/+bug/1749309/+subscriptions -- ubuntu-bugs mailing list email@example.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs