On my Ubuntu system I have activated the 'Time Synchronization via Internet'. Because of that the ntp daemon gets started.
What I don't understand: Why needs ntpd an open UDP port 123? Actually, I don't want to have a ntp server running on my machine - my intention was only to synchronize my time with ntp servers on the internet.
So, my question are:
Why is there an open port by default if I only want to synchronize with other ntp servers?
Isn't that a unnecessary security risk?
Has somebody a good solution for my 'problem'?
Thank you very much for your help in advance. I searched the internet already but I couldn't find sastisfactory answers.