This is syslog while restarting zerotier-one.service:
Nov 25 12:07:23 kronos systemd[1]: Stopping ZeroTier One…
Nov 25 12:07:23 kronos systemd-networkd[132609]: zt3jnsszad: Link DOWN
Nov 25 12:07:23 kronos systemd-networkd[132609]: zt3jnsszad: Lost carrier
Nov 25 12:07:23 kronos systemd[1]: Stopping Netscript ifup for zt3jnsszad…
Nov 25 12:07:24 kronos netscript[1591125]: Usage: netscript ifup|ifdown|ifqos|ifreload
Nov 25 12:07:24 kronos netscript[1591125]: {eth0|enp1s0|all}
Nov 25 12:07:24 kronos systemd[1]: netscript@zt3jnsszad.service: Control process exited, code=exited, status=1/FAILURE
Nov 25 12:07:24 kronos systemd[1]: netscript@zt3jnsszad.service: Failed with result ‘exit-code’.
Nov 25 12:07:24 kronos systemd[1]: Stopped Netscript ifup for zt3jnsszad.
Nov 25 12:07:25 kronos systemd[1]: zerotier-one.service: Succeeded.
Nov 25 12:07:25 kronos systemd[1]: Stopped ZeroTier One.
Nov 25 12:07:25 kronos systemd[1]: Started ZeroTier One.
Nov 25 12:07:25 kronos systemd-networkd[132609]: zt3jnsszad: Link UP
Nov 25 12:07:25 kronos networkd-dispatcher[563]: WARNING:Unknown index 22 seen, reloading interface list
Nov 25 12:07:25 kronos systemd-networkd[132609]: zt3jnsszad: Gained carrier
Nov 25 12:07:25 kronos systemd-udevd[1591134]: Using default interface naming scheme ‘v245’.
Nov 25 12:07:25 kronos systemd-udevd[1591134]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable.
Nov 25 12:07:25 kronos systemd-udevd[1591134]: zt3jnsszad: Could not generate persistent MAC: No data available
Nov 25 12:07:25 kronos systemd[1]: Unnecessary job for /sys/subsystem/net/devices/zt3jnsszad was removed.
Nov 25 12:07:25 kronos systemd[1]: Started Netscript ifup for zt3jnsszad.
Nov 25 12:07:25 kronos sh[1591195]: Configuring interface: zt3jnsszad.
Nov 25 12:07:26 kronos systemd-networkd[132609]: zt3jnsszad: Gained IPv6LL
Ok, my apologies. One reboot and everything is back up again. I didn’t want to do this at first as this is quite critical service here, but decided to do it anyway since you couoldn’t reproduce.