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I've been struggling to find how I can make my server's time more accurate.
I could use NTP to sync with a public NTP server but it bothers me that it's so insecure. Same problem with radio clocks. A GPS clock is not an option cause the server is inside.
So I've been looking for an hour and I can't find any consumer device that's an accurate (atomic or close to atomic) computer clock. Does anyone know of one or do you need a nuclear research lab to get one of those?
And even if I can't have my own, can someone suggest a USB radio or GPS clock that's likely to work indoors (in Canada)?
GPS can work. Modern GPS receivers can receive signals inside, and you can always use either a bluetooth GPS receiver, or a USB receiver with an extended cable. Bluetooth is probably the best choice, and you can get a bluetooth GPS receiver rather cheaply. If it's so far inside that neither bluetooth nor USB is possible, you really need to rethink your problem, and go with ntp regardless of the security issues. You will not be able to acquire your own atomic clock, and even if you had one, you would have to synchronize it before you could use it. Don't even think about that possibility.
Create a virtual machine that is used for ntp. Use it as your master time.
In a real sense, if your system is connected to the internet, it is not considered secure. I'd wonder who has been attacked by ntp.
It may be possible to secure it http://www.ntp.org/ntpfaq/NTP-s-algo-crypt.htm
The US provides North America with a number of time signals on various bands from lf to hf and even via different satellites. As to why you'd need such accuracy on a pc or server is odd to me. The quality of the time is way beyond what your computer could need.
My dislike of plain text NTP over the internet can be explained like this, ask yourself the question: would you be ok with me connecting to your computer remotely whenever I want and changing your clock to whatever I want? I know it's silly (why would someone care to do that) but it just seems plain wrong, you don't allow things like as a matter of principle.
Right now I'm relying on my Linux clock (I think the BIOS clock is only used during bootup, which happens very rarely) and I'd be perfectly happy with that except that it drifts quite a bit, maybe 30 minutes every month, which is a problem for sent/received emails, various server logs, version control, etc. So yeah..
as to a caesium ion clock or a strontium one
have fun trying to get those isotopes
you used to be able to , but ...... not now
I don't really need one of those, even though it would be super cool, but I would like something better than what I have now. Why is that so hard? I mean even my cheap wristwatch is about 50 times more accurate than my server
Modern GPS receivers can receive signals inside, and you can always use either a bluetooth GPS receiver, or a USB receiver with an extended cable.
That would be perfect for me, can you suggest what hardware to get and how to configure it as a time source?
This being a Linux forum I'll take some heat for this but I prefer using OpenNTP from the folks who brought us OpenBSD. Yeah, it's technically not as accurate to the umpteenth decimal place but it's plenty good enough and, more importantly, the code has been audited by some of the best of the best.
So you set your (open)ntpd daemon up to sync with some public TierII servers (use us.pool.ntp.org). Then you configure your (open)ntpd daemon to _listen_ for ntp requests _only_ on safe ports, i.e. internal LAN interfaces, where you have at least some control over who/what can poll your time server.
My dislike of plain text NTP over the internet can be explained like this, ask yourself the question: would you be ok with me connecting to your computer remotely whenever I want and changing your clock to whatever I want?
The issue regarding the ntp debate is not so much about changing your clock. It is about ntp requiring only a small amount of data to make a request for accurate time then it send back about twice the amount of data received. With all the ntp servers that automatically respond, it causes an issue where it can be used for ddos attacks. Who gives a rats arse about what time your computer shows? If someone will actually spend time to hack your machine, i can promise you they will not even bother with something arbitrary like that.