Unix and Linux Stack Exchange
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Questions tagged [ntp]

The Network Time Protocol, is used to synchronize system clocks to precision time servers on the internet or locally connected devices such as a GPS.

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ntpd vs. systemd-timesyncd - How to achieve reliable NTP syncing?

When I query the status of the NTP daemon with ntpdc -c sysinfo I get the following output: system peer: 0.0.0.0 system peer mode: unspec leap indicator: 11 stratum: 16 precision: -20 root distance: …
a_guest
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chrony vs. systemd-timesyncd – What are the differences and use cases as NTP clients?

Somehow but not quite building upon the older question "ntpd vs. systemd-timesyncd - How to achieve reliable NTP syncing?", I'd like to ask about the differences between chrony and systemd-timesyncd in terms of an NTP client. I know that…
wedi
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how do you set up a linux client to use ntp information provided through dhcp?

there are so many tutorials out there explaining how to setup dhcpd server, in relation to providing ntp suggestions to dhcp clients, that I had always thought that ntp configuration was carried out automatically. Recently I started seeing clock…
nass
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Why am I getting apparmor error messages in the syslog about NTP and LDAP?

On my newly installed Ubuntu 12.04 machine, with ntp and slapd installed, the following messages appear in /var/log/syslog at regular intervals: Feb 23 18:54:07 my-host kernel: [ 24.610703] type=1400 audit(1393181647.872:15): apparmor="DENIED"…
FixMaker
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How to keep Debian internal clock synchronized (with NTP servers)?

I have a home server which runs an up to date Debian 7.5 (wheezy) installation. I just discovered that the server has its internal clock set to ± 3 minutes in the future. I knew that I could use NTP to synchronize Debian (and the motherboard…
A.L
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What is the recommended way to synchronize time using NTP?

This question has come up a number of times in a localized way, this question is meant to provide the preferred/best method for synchronizing a system's clock using NTP. The solution should handle multiple issues correctly, such as: Correct for…
slm
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Ghost NTP server on Debian 8.6

So the university IT security team and I have been going around and around on this with no breaks... anyone have any thoughts on this: I recently set up a small file server for my lab running Debian 8.6 on a dedicated computer (Intel Avoton C2550…
Tim Otchy
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Difference between chronyd and ntpd

What is the difference between chronyd and ntpd? I know that ntpd can gradually adjust the time so that it can converge gradually to the the reference clock. Can this be done with chrony?
ComBin
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Why does ntpq -pn report "Connection refused"?

I've recently setup a CentOS 6.x system with NTPD running and am encountering this error when I run ntpq -pn: $ ntpq -pn ntpq: read: Connection refused I know that ntpd is up and functioning via the ntpstat command: $ ntpstat synchronised to NTP…
slm
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ntpdate -d seems successful, but ntpdate returns no server suitable

I've got a system that is not running ntpd on which I'm attempting to update the clock using ntpdate. The system is an appliance that appears to be CentOS 6 based. When I run ntpdate 0.pool.ntp.org, I get: 8 Sep 17:52:05 ntpdate[7445]: no server…
csyria
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How to get system time with microsecond Resolution

I want to know current system time with microsecond Resolution. date +%s returns Time in seconds since epoch(1-1-1970). How can I get time in microseconds Resolution. How much delay is in querying this value? By delay I mean suppose at time t secs…
Coderaemon
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How does Linux use a real time clock?

I'm investigating a very strange effect on some Beagle Bone Black (BBB) boards. We're seeing occasional jumps of a few months in the system clock which always correlate with systemd-timesyncd updating the system clock. We see 2 to 3 of these a…
Philip Couling
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Strip specific option from a response in dhclient

I aim to prohibit dhclient from updating my NTP config with servers received via DHCP, as it is the default on Debian/Ubuntu. However, my DHCP server ignores the list of requested options (from the request setting) and its answers always contain an…
F30
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timed out, nothing received

I tried all and googled a lot! But I can't make work NTP on my server. This post is last hope! I have installed ntp on debian server with this configuration (/etc/ntp.conf): driftfile /var/lib/ntp/ntp.drift statdir /var/log/ntpstats/ statistics…
Test
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Chicken and egg problem with NTP and Bind

This a report of a problem I solved but I feel the solution could be useful to other. The problem appeared on a Raspbian 9.13. For some - probably hardware - reasons still to be discovered, my Raspberry pi-based router crashed and could not restart.…
David Verdin
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