I tried searching for answers as to why these machines are reaching out to numerous locations despite not using PrusaConnect. Location lookup returns the expected Czech, as well as location across the US. I recently also set a friend up with with an Elegoo printer and that was expectedly noisy as hell, but I was surprised with Prusa being the ‘privacy pick’.
For those curious, here’s the logs since about midnight, it seemingly doesn’t talk during the day.
209.51.161.238:123
195.113.144.238:123
23.150.41.122:123
193.29.63.226:123
162.244.81.139:123
64.246.132.14:123
172.104.182.184:123
66.85.78.80:123
68.234.48.70:123
129.250.35.250:123
Bang on. Something is trying to update its clock.
OP, I suggest you ok that traffic, but if you want to lock it down allow *.pool.ntp.org and *.(Your country prefix).pool.ntp.org
https://www.ntppool.org/en/
Or spin up your own NTP server and NAT those requests to it.
Again, why would a printer need a clock for?
Anything that connects to the network needs a synchronized clock with other devices it directly communicates with in order to make sure it’s not being subjected to timing attacks. This has been standard practice for 25 years, maybe more, in the end user world because some high profile computer screw ups made use of it. People with weird systems, off the gridders of olde and ppl still on dial up in the teens had some interesting problems to solve when generally all ISPs got drug kicking and screaming to the table by os updates that made synchronized clocks a non negotiable requirement.
Ofcours, to print time
If it’s a multifunction, printing the time/date on the fax.
It is a 3D printer
To show the expected completion time of the print.