I have set up an NTP server on my Linux box that I use as file server so I can synchronise the time on my Linux desktop computer with it. I did it for experimantel reasons, but it left me wondering... why do I need an NTP server when there are millions of them already available.

In fact, running an NTP server requires another NTP server to sychronise the clock all the time. But is that always the case? I mean, if each NTP server depends upon another in order to work properly, what happens if there's only one NTP server (or even two)?

Or is there one global computer on the Internet that all the NTP servers will eventually talk to?

TIA,
Dai

I don't believe there is ONE global NTP server as there are a bunch of different time zones depending on geographic location. Not only that, if there was one, it would be screaming due to the number of requests it gets. There's a bunch for a variety of reasons: redudancy, network performance, and whatnot.

At my company, we have 2 central NTP servers. Why? Because some of our servers are on different lan segments and they don't have access to the outside world. Also, we have over 300 servers and it's much more efficient for them to sync against one of our NTP servers than the ones that are listed publicly.

-twantrd