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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Force NTP step whenever the Internet comes up
Assume there is a PC with dead CMOS battery and unreliable Internet connection.
As far as I understand, both chrony and ntpd try to correct huge time differences (years) once – upon startup, – but ...
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System time synchronization between two hosts using linuxPTP
I would like to setup a high-precision system time synchronization between two machines using linuxptp.
On the first host:
the system time is periodically synchronized using NTP using an interface ...
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How to update time zone list in Linux (Debian)?
I'm going to set time zone to my locale on Debian. The DST has been removed in my region since the last year (2022, Sep.), but it's apparently not updated in Debian time zone list. What is the best ...
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How to set NTP synchronized to yes in Linux without NTP sync?
How to set NTPSynchronized to yes in Linux without actual NTP synchronization?
I just want to cheat some program.
]$ timedatectl show -p NTPSynchronized
NTPSynchronized=yes
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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 ...
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Ntpd client strange behavior
Jetson NX with latest Jetpack, NTP Ver. 4.2.8p10
I have some pools in /etc/ntp.conf (0.europe.pool.ntp.org)
When I try ntdate -q 0.europe.pool.ntp.org all is ok
But there is nothing except one ...
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Is there a way for accurate timekeeping on Linux/Debian without NTP/Internet?
The only way I could get a working clock on Debian is by using NTP to sync the clock as described here.
Is there a way to have a reliably accurate clock without NTP and without any Internet connection?...
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How can I determine the current reliability [correctness] of the system time?
I'm working on a project which will acquire a lot of timestamped data at fairly high resolution (50 samples per second) over a very long period of time (years).
The solution includes various failover ...
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Chrony - Synchronize the date and time of all host computers in a network without internet connection
I have two machines,
host A with IP 192.168.0.1
host B with IP 192.168.0.2
They connected to the same network and I would like to set the date and time of machine B to match those of machine A. ...
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Why is my ntp not updating?
I have a Debain console-only system.
I just realized it's not updating it's clock:
$ date
Mon 10 Aug 20:33:23 BST 2020
$ ntpdate
10 Aug 20:27:45 ntpdate[8029]: no servers can be used, exiting
$ ...
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NTP (NTPSec-1.2.2) client is able to sync time from NTP server even if the server does not switches from candidate to become system peer
I have a NTP setup (client-server association) where on the client side, I have below lines(among others) in ntp.conf:
# This should be maxclock 7, but the pool entries count towards maxclock.
tos ...
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Where is timedatectl information stored?
I am working on an embedded system without RTC battery. The time is synchronized via NTP when internet connection is available (which does not always happen). When the device is shut down, the time is ...
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How do I install NTP server on Windows and NTP client on Debian and configure them both?
I have configured an NTP server on my Windows, including the registry edits, services edits, and firewall. I started the time service too. I connected a Debian system to the same network and ...
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Using RTC PPS for syncing computer by NTP
I've seen a decent amount of documentation for how one would use a GPS and its PPS signal along with an NTP package (like ntpd or chrony) to synchronize the computer's clock.
I have a need similar to ...
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Ntpd sets the sys time to the year 2156 after syncing to primary server
I have a couple boards that are setup to get time from another board as the source of truth.
The primary has correct time, but when the other supporting boards attempt to sync to it, they select the ...
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Read NMEA messages in ntpd to adjust system time
I want to configure ntpd so that it reads NMEA messages from an HTTP-server and uses their time to adjust system time.
For that I did the following.
Stored the following NMEA-messages in messages.txt:
...
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What should be the reason for PTP for not able to access shared memory?
I'm using yocto rootfs where I have installed linuxptp, chrony, and gpsd. So I'm trying to use the shared memory 2 for ptp by using following file /etc/ptp4l.conf
[global]
# only syslog every 1024 ...
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Relocation error when running NTPv4 (cross-compile) on ARM device
The error message I am getting when running ntp-keygen (or ntpd) on my ARM device is:
./ntp-keygen: relocation error: ./ntp-keygen: symbol DSA_generate_parameters_ex, version OPENSSL_1_1_0 not defined ...
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Error compiling NTPv4 for ARM with OpenSSL
The error is along the lines of
"ntp_crypto.c:2248:2: error: unknown type name 'DSA_SIG'; did you mean 'ECDSA_SIG'?"
make fails with the following output:
tp_crypto.c: In function '...
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Missing features compiling NTP vs installing already built
I have found that if I compile NTP myself, the package ntp-keygen is missing Autokey authentication features.
The help screen of my compiled ntp is as follows:
Whereas if I just apt-get install ntp, ...
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"no server suitable for synchronization found" error when trying to run `ntpdate`
I am trying to get ntp to sychronise the time with the default server pool that is set on CentOS 6.
NTP has been stopped and started but it does not help. I have tried to force the update with the ...
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How to install a NTP Client into a yocto-base Linux distribution?
I'm developing a yocto-base Linux distribution by zeus yocto release.
I need to add a NTP client to the distribution but I don't need to install the NTP server inside the image.
I have found the ...
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Understanding configuration of NTP server
I opened /etc/ntp.conf file. I have the following entries:
server 0.centos.pool.ntp.org
restrict 0.centos.pool.ntp.org mask 255.255.255.255
I am not sure what mask 255.255.255.255 is doing exactly? ...
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System clock not synchronized with NTP server using systemd-timesyncd
I followed this answer here, but it seems that my system clock doesn't synchronize with NTP server:
$ cat /etc/debian_version
10.9
$ egrep -v "^$|^#" /etc/systemd/timesyncd.conf
[Time]
NTP=x....
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Chrony fails to sync with NTS enabled
I have configured Chrony server and client on two Centos 9 Stream machines. Without NTS everything is fine and the time is being synced. However, when I enable NTS, and configure the server to use ...
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How to enforce NTP authentication?
I have configured NTP server on an Ubuntu machine and NTP client on a Centos 9 Stream using Chrony. I have enabled authentication on both server and client, but when I put differnt keys on the sides, ...
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NTP - tos maxdist explained
I had an issue with NTP today that I resolved by adding the line tos maxdistance 30 to my ntp.conf file. I found this solution online and am now trying to understand exactly what this line means. I ...
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What does the '#' prefix mean for "ntpq -p"
I'm adding an NTP server to my npt.conf file and wanted to check if it was successfull using "ntpq -p". In the output I see several prefix, I know that '*' indicates the one being used, '+' ...
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how to test ntp servers as real servers that responding without using ping test
we have bash script that configured the chrony.conf
script check if ping is ok on ntp1 and ntp2 ( ntp servers )
and then script insert the ntp servers to /etc/chrony.conf ( only if ping success )
...
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ntpq peers output explanation
I got following output from ntpq command:
# ntpq -pn
remote refid st t when poll reach delay offset jitter
=================...
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What is timedatectl's definition of "synchronized"?
timedatectl produces the following output:
Local time: Tue 2022-05-10 01:07:46 UTC
Universal time: Tue 2022-05-10 01:07:46 UTC
RTC time: Tue 2022-05-10 01:07:...
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How can I have ntpd act as a client only, and not a server?
I'm trying to configure a linux machine for NTP, but don't want that machine to reply at all to other machines which may make requests. But it will be acting as an NTP client, which means it will ...
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chrony keeps going in future
I have chrony installed on a centos 8 system and it keeps setting the time in the future by about 2 hours every 2 days. I have to keep restarting the service and do an ntpdata to fix itm and it is ...
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timedatectl: problem with NTP returning localtime instead of UTC time
On my embedded Linux, I have a problem with time zones:
I'm trying to keep the UTC time in the RTC of the device. But somehow, timedatectl keeps adjusting time to the local time and not the UTC time, ...
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Why is my NTP time sync root dispersion degrading over time?
I have a test network setup with a Mikrotik router with a 4G/LTE internet connection, connected to one Raspberry Pi via Ethernet cable, and to 30 more Raspberry Pis via wifi.
I have set up NTP with ...
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System clock synchronization is not working after upgrading to pop_os 21.10
I've recently upgraded to pop_os 21.10 from 21.04 and every time I boot my device I get random time/date set on my machine. Automatic date and time under settings is not working.
The following is the ...
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Syncing Debian ntpd with Windows time server [duplicate]
unfortunately my problem listed here was not solved. It would seem that the issue was not with the ntpdate at all: when bypassing the university network all together, time sync works correctly.
The ...
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Automatic time synchronization: `ntpdate` works but `chrony` does not
I have a problem with time synchronization of my Linux server. Both this machine and the NTP server are located in a (smaller) university data center hence the local address.
What is strange is that ...
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Unexpected critical dependency on LDAP
I'm using LDAP for user authentication only (nsswitch.conf below) on Ubuntu 18.04. However if the host cannot connect to the LDAP server at boot time, startup is blocked by NTP and DNS.
The LDAP ...
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Possibly stuck in a XY problem with NTP
I have two stand-alone systems, which I'll refer to as Vanguard and Crucible.
Vanguard has an RTC battery, whereas Crucible does not. Vanguard's date and time will be updated periodically by hand. ...
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ntp server reachable but never select/set the time
We have some embedded devices using ntpd(4.2.8p10) to sync the time. One of our customers is using their own ntp server inside an internal network. From the ntpd -dgq debug mode, we found the server ...
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Why ntpd prompt 'no server found' whenI sync time manually?
My server is hosted in IDC, due to in this IDC server can't access to Internet, so I can use Internet NTP server. But IDC service provider have a atomic clock, so I can sync time with atomic clock.
...
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Where, besides ntp.conf, do NTP servers used by ntpd come from?
The only NTP servers I have defined in /etc/ntp.conf are as follows:
pool 0.debian.pool.ntp.org iburst
pool 1.debian.pool.ntp.org iburst
pool 2.debian.pool.ntp.org iburst
pool 3.debian.pool.ntp.org ...
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Chrony tracking.log showing IP Address of 0.0.0.0
I have a NTP server running chronyd that is configured with the following pool:
pool 0.dk.pool.ntp.org iburst
pool 1.dk.pool.ntp.org iburst
pool 2.dk.pool.ntp.org iburst
pool 3.dk.pool.ntp.org iburst
...
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Crazy clock drift on ancient VM
I am stuck with a Centos 5.3 VM (running on Proxmox) which exhibits huge clock drift. It was configured to run ntpdate every 5 minutes but the clock was still getting out of sync by up to 20 seconds ...
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systemd-timesyncd: Timed out
I'm struggling to synchronize my system clock on Pop OS 21.04.
I've read a lot of posts on the subject but it doesn't seem to help.
my system clock are not synchronized, which caused issues with ...
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is there a generic way to check if time is synchronised
I am writing some software that runs on a system that may or may not have access to the internet and I want it to behave differently depending on whether the clock is synchronised, It will likely run ...
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Does having hyperv-daemons enabled show that the system clock is synchronised by timedatectl?
We are opting to disable chronyd in favour of using hyperv-daemons to keep our server clocks in sync so that the guest OS time is managed by the machine that the VM is running on.
After disabling ...
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Synchronizing NTP machines with a high root-time server
I have a small network of machines that use systemd-timesyncd.service and need their clocks to be synchronized. They don't need to be correct, just synchronized. I have designated one of the ...
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Is ntpd working?
I'm running ntpd on my machine, but I'm not sure if it is working correctly. How can I query ntpd to determine whether it has successfully connected to time servers and that my kernel time is ...
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