I can see the same issue once I upgraded to Ubuntu 17.04 (previous Ubuntu 16.10 was not affected). Sometimes when I resume my notebook from sleep, DNS stops working for a few minutes. Restart of network or systemd-resolved didn't help. It seems that it starts working once system turns DNSSEC mode off:
$ service systemd-resolved status ... dub 17 13:53:38 mira-HP-ENVY-Notebook systemd-resolved[13838]: DNSSEC validation failed for question docs.google.com IN A: failed-auxiliary dub 17 13:53:38 mira-HP-ENVY-Notebook systemd-resolved[13838]: DNSSEC validation failed for question docs.google.com IN AAAA: failed-auxiliary dub 17 13:53:38 mira-HP-ENVY-Notebook systemd-resolved[13838]: DNSSEC validation failed for question www.googleapis.com IN A: failed-auxiliary dub 17 13:53:39 mira-HP-ENVY-Notebook systemd-resolved[13838]: Using degraded feature set (UDP) for DNS server 10.0.0.138. dub 17 13:53:39 mira-HP-ENVY-Notebook systemd-resolved[13838]: Server 10.0.0.138 does not support DNSSEC, downgrading to non-DNSSEC mode. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1656830 Title: Ubuntu MATE 17.04: No DNS resolution caused by systemd-resolved To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1656830/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
