5 ms·

I thought NTP was a protocol, not a piece of software. Is the article conflating them, or is there only one single implementation of it that everyone relies upo

by kijeda 10y ago

I thought NTP was a protocol, not a piece of software. Is the article conflating them, or is there only one single implementation of it that everyone relies upon?

notaplumber 10y ago
There's OpenNTPD which is maintained by the OpenBSD/OpenSSH developers. It has been poorly criticized for its focus on security rather than absolute precision, but it's more than adequate for most peoples timekeeping needs. http://www.openntpd.org/ http://www.openntpd.org/ It has privilege separation, sandboxing and if your OS/distribution uses LibreSSL it implements HTTPS constraints. http://man.openbsd.org/ntpd.conf.5 http://man.openbsd.org/ntpd.conf.5 http://man.openbsd.org/ntpd.8 http://man.openbsd.org/ntpd.8 http://man.openbsd.org/ntpctl.8 http://man.openbsd.org/ntpctl.8
- PhantomGremlin 10y ago
  it's more than adequate for most peoples timekeeping needs Yes it is. I'm on a cable modem and currently using OpenNTPD to talk to 5 NTP servers. My largest offset is currently 3.6 milliseconds. That's fine for general purpose computing. Anyone who needs better should probably buy some NTP or PTP hardware for his LAN.
jerdfelt 10y ago
There is NTP the protocol[1], and there is NTP the implementation[2]. While the implementation is popular, there are alternatives. There is also OpenNTPd, chrony and ntimed for instance. There are also alternatives to the NTP protocol too, such as PTP and SNTP. [1]https://www.ietf.org/rfc/rfc5905.txt https://www.ietf.org/rfc/rfc5905.txt [2]http://www.ntp.org/ http://www.ntp.org/
- tatersolid 10y ago
  Don't forget the billion-plus machines out there running Windows Time Service (which strangely has had zero security issues I can remember, even when running in server mode).
  - JdeBP 10y ago
    W32Time has different kinds of issues, in my experience. With it, one's problems tend to be that, by design until very recently, it doesn't provide to-the-second accuracy. * https://blogs.technet.microsoft.com/askds/2007/10/23/high-accuracy-w32time-requirements/ https://blogs.technet.microsoft.com/askds/2007/10/23/high-ac... * https://greyware.com/software/domaintime/v5/overview/w32time.asp https://greyware.com/software/domaintime/v5/overview/w32time... * https://technet.microsoft.com/en-gb/windows-server-docs/identity/ad-ds/get-started/windows-time-service/windows-2016-accurate-time https://technet.microsoft.com/en-gb/windows-server-docs/iden...
- JdeBP 10y ago
  ... and TAICLOCK. * http://cr.yp.to/proto/taiclock.txt http://cr.yp.to/proto/taiclock.txt

by kijeda 10y ago

I thought NTP was a protocol, not a piece of software. Is the article conflating them, or is there only one single implementation of it that everyone relies upon?

notaplumber 10y ago

There's OpenNTPD which is maintained by the OpenBSD/OpenSSH developers. It has been poorly criticized for its focus on security rather than absolute precision, but it's more than adequate for most peoples timekeeping needs. http://www.openntpd.org/ http://www.openntpd.org/ It has privilege separation, sandboxing and if your OS/distribution uses LibreSSL it implements HTTPS constraints. http://man.openbsd.org/ntpd.conf.5 http://man.openbsd.org/ntpd.conf.5 http://man.openbsd.org/ntpd.8 http://man.openbsd.org/ntpd.8 http://man.openbsd.org/ntpctl.8 http://man.openbsd.org/ntpctl.8

PhantomGremlin 10y ago
it's more than adequate for most peoples timekeeping needs Yes it is. I'm on a cable modem and currently using OpenNTPD to talk to 5 NTP servers. My largest offset is currently 3.6 milliseconds. That's fine for general purpose computing. Anyone who needs better should probably buy some NTP or PTP hardware for his LAN.

jerdfelt 10y ago

There is NTP the protocol[1], and there is NTP the implementation[2]. While the implementation is popular, there are alternatives. There is also OpenNTPd, chrony and ntimed for instance. There are also alternatives to the NTP protocol too, such as PTP and SNTP. [1]https://www.ietf.org/rfc/rfc5905.txt https://www.ietf.org/rfc/rfc5905.txt [2]http://www.ntp.org/ http://www.ntp.org/

tatersolid 10y ago
Don't forget the billion-plus machines out there running Windows Time Service (which strangely has had zero security issues I can remember, even when running in server mode).
- JdeBP 10y ago
  W32Time has different kinds of issues, in my experience. With it, one's problems tend to be that, by design until very recently, it doesn't provide to-the-second accuracy. * https://blogs.technet.microsoft.com/askds/2007/10/23/high-accuracy-w32time-requirements/ https://blogs.technet.microsoft.com/askds/2007/10/23/high-ac... * https://greyware.com/software/domaintime/v5/overview/w32time.asp https://greyware.com/software/domaintime/v5/overview/w32time... * https://technet.microsoft.com/en-gb/windows-server-docs/identity/ad-ds/get-started/windows-time-service/windows-2016-accurate-time https://technet.microsoft.com/en-gb/windows-server-docs/iden...
JdeBP 10y ago
... and TAICLOCK. * http://cr.yp.to/proto/taiclock.txt http://cr.yp.to/proto/taiclock.txt