systemd-timesyncd: "Network configuration changed" spam

[jass0]

SOLVED:
It was caused by dhcp server misconfiguration!

I just recently enabled systemd-timesyncd. I am running an up-to-date arch linux.

I get this spam in journalctl:

$this->bbcode_second_pass_code('', '
Jan 20 18:28:03 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:28:03 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:28:56 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:28:56 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:29:49 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:29:49 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:30:43 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:30:43 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:31:36 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:31:36 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:32:27 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:32:27 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:33:21 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:33:21 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:34:14 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:34:14 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:35:07 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:35:07 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:36:01 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:36:01 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:36:54 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:36:54 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:37:49 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:37:49 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:38:42 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:38:42 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:39:36 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:39:36 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:40:29 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:40:29 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:41:23 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:41:23 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:42:15 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:42:15 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:43:09 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:43:09 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:44:01 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:44:01 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:44:53 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:44:53 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:45:46 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:45:46 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:46:39 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:46:39 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:47:33 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:47:33 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:48:24 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:48:24 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:49:14 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:49:15 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:50:08 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:50:08 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:50:58 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:50:58 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:51:50 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:51:50 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:52:45 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:52:45 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:53:38 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:53:38 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:54:33 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:54:33 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:55:24 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:55:24 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:56:17 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:56:17 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:57:10 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:57:10 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:58:04 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:58:04 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:58:56 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:58:56 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 18:59:46 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 18:59:46 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 19:00:39 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 19:00:39 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 19:01:30 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 19:01:30 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 19:02:24 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 19:02:24 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
Jan 20 19:03:17 cubie systemd-timesyncd[254]: Network configuration changed, trying to establish connection.
Jan 20 19:03:17 cubie systemd-timesyncd[254]: Synchronized to time server 194.100.2.194:123 (2.fi.pool.ntp.org).
')

Any idea how to stop this?

I found this: Bug 87505 - systemd-timesyncd "Network configuration changed" spam on IPv6 router advertisements, but my router has IPv6 disabled (running DD-WRT)

Here's ip monitor log, it seems to be somehow linked to this:
$this->bbcode_second_pass_code('', '
2: eth0 inet 192.168.0.11/24 brd 192.168.0.255 scope global dynamic eth0
valid_lft 120sec preferred_lft 120sec
192.168.0.1 dev eth0 lladdr c0:ff:d4:93:3a:ff STALE
192.168.0.1 dev eth0 lladdr c0:ff:d4:93:3a:ff PROBE
192.168.0.1 dev eth0 lladdr c0:ff:d4:93:3a:ff REACHABLE
2: eth0 inet 192.168.0.11/24 brd 192.168.0.255 scope global dynamic eth0
valid_lft 120sec preferred_lft 120sec
192.168.0.1 dev eth0 lladdr c0:ff:d4:93:3a:ff STALE
192.168.0.1 dev eth0 lladdr c0:ff:d4:93:3a:ff PROBE
192.168.0.1 dev eth0 lladdr c0:ff:d4:93:3a:ff REACHABLE
2: eth0 inet 192.168.0.11/24 brd 192.168.0.255 scope global dynamic eth0
valid_lft 120sec preferred_lft 120sec
')

Which seems related to this (tshark capture):
$this->bbcode_second_pass_code('', '
18 2.702927135 192.168.0.11 → 192.168.0.1 DHCP 329 DHCP Request - Transaction ID 0x1ebab5bf
19 2.703773472 192.168.0.1 → 192.168.0.11 DHCP 342 DHCP ACK - Transaction ID 0x1ebab5bf
183 55.729063611 192.168.0.11 → 192.168.0.1 DHCP 329 DHCP Request - Transaction ID 0x1ebab5bf
184 55.729857279 192.168.0.1 → 192.168.0.11 DHCP 342 DHCP ACK - Transaction ID 0x1ebab5bf
238 106.995765998 192.168.0.11 → 192.168.0.1 DHCP 329 DHCP Request - Transaction ID 0x1ebab5bf
239 106.996622043 192.168.0.1 → 192.168.0.11 DHCP 342 DHCP ACK - Transaction ID 0x1ebab5bf
')

I think it has to do with this: https://github.com/systemd/systemd/issues/3888