Public bug reported: In systemd-timesyncd ntp.ubuntu.com is used as fall back ntp server. However, one of the addresses it resolves to is not available for quite some while:
[...] Apr 14 07:37:42 singold systemd-timesyncd[773]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 14 08:10:45 singold systemd-timesyncd[773]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 15 08:20:48 singold systemd-timesyncd[802]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 15 12:47:56 singold systemd-timesyncd[842]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 16 07:39:05 singold systemd-timesyncd[842]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 18 18:11:05 singold systemd-timesyncd[842]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 19 23:45:04 singold systemd-timesyncd[758]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 20 14:20:46 singold systemd-timesyncd[758]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 21 09:42:45 singold systemd-timesyncd[758]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 22 09:41:52 singold systemd-timesyncd[672]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). Apr 22 09:47:03 singold systemd-timesyncd[672]: Timed out waiting for reply from [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com). [...] It turns out that from all the A and AAAA records ntp.ubuntu.com resolves the, 2001:67c:1560:8003::c8 seems to be constantly down. This leads to time synchronisation problems for people using IPv6, as it seems timesyncd keeps returning to the same server over and over again, instead of trying the other ones DNS returns. A practical solution to this would be to simply remove 2001:67c:1560:8003::c8 from the DNS entry for ntp.ubuntu.com. ** Affects: systemd (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/1766106 Title: ntp.ubuntu.com not reliable, but used in standard configuration To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1766106/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs