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Questions tagged [ntp]

NTP stands for Network Time Protocol, and it is an Internet protocol used to synchronize the clocks of computers to some time reference.

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Query on NTP current time source

I have a query regarding ntpd options and the ntpq command. I have set up a local NTP Server in Ubuntu 14.04 PC and NTP Client is a custom development platform based on Renesas RZ/G1H. I have ...
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ntp offset with stratum 1 , when using stratum 2

I was searching for a solution but didn't find clear answer. In my company, all our servers are syncing time with one of our private ntp servers (which are stratum 3 if I'm correct). These stratum 3 ...
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securing/hardening ntp client on Linux servers - config file

I have a clean install of Debian with the NTP client. I was given settings to secure secure my NTP client configuration. I know how to add them to the /etc/ntp.conf file but I am not if settings need ...
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2answers
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chrony does not log anything on my ec2 instance

i am trying to gather statistics from the chrony daemon on my EC 2 (Ubuntu 18.04.2 LTS) instance. i have followed aws's guide on how to set it up and it runs as expected. i need to compare the time ...
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SOLVED NTP No Server Suitable For Synchronization Found Centos

I'm trying to set up an ntp server, and I can't query it. Whenever I try, I get this message: 6 Mar 18:57:01 ntpdate[27050]: no server suitable for synchronization found Here is my ntpd.conf file #...
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Red Hat Linux NTP Inconsistent Values

Recently I am experiencing NTP high delay and offset values on my server. $ ntpq -p remote refid st t when poll reach delay offset jitter =====================================...
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NTP Stratum Won't “Fudge”

I have two servers, blue and green. I want blue to pull time from green but it won't because the stratum on green is too high. Green has a regular internet connection. Blue does not. In googling ...
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What sources does public NTP servers use to ensure time sync?

As from the title, I would like to know what sources “pool.ntp.org” and other big NTP service providers use in order to ensure they are in sync and serving clients the exact date and time.
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ntpdate take long time to sync (not ntpd)

I have referred ntpdate -d Server dropped Strata too high. This is a similar but different question. I having two devices. Freescale ARM board (NTP server) Tinker board (client) In the Freescale ...
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1answer
61 views

NTP and NTPDATE over IPv6 Does Not Work

I have been working with setting up an NTP server for testing IPv6 syncing. I am unable to find any help with getting the configuration to work. If ntp 4.2.6 and ntpdate 4.2.6 say they support IPv6, ...
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Verify internal NTP server is sending the correct time?

I have two NTP stratum 3 servers running and wanted to create a simple check that I could tell if either of the servers time drifted and alert that it's not synced properly with the public stratum 2 ...
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1answer
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standalone NTP config

I am trying to setup local NTP server for some testing. I have installed NTP on Ubuntu 18.04 and commented server-pool block in the config file Here is the full config : driftfile /var/lib/ntp/ntp....
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Force systemd timesyncd to sync time with NTP server immediately

I've configured systemd timesyncd to get it's time from a NTP server: /etc/systemd/timesyncd.conf > NTP=ca.pool.ntp.org systemctl restart systemd-timesyncd.service timedatectl set-ntp true The ...
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1answer
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Why is dbus-org.freedesktop.timedate1 started so frequently?

I have some Ubuntu 18.04.1 servers. They all show this service being started rougly every 10 minutes. Jan 7 06:29:05 csrf-prod1-vm dbus-daemon[434]: [system] Activating via systemd: service name='...
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Deny NTP servers with stratum more than specific level

How can I deny in my /etc/ntp/ntp.conf to sync with the NTP server with specific stratum level (e.g. more than 5 )? I have a bad NTP server in my local network and sometimes is going really wrong ...
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2answers
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NTP 27 seconds Difference

I have DMZ server configured as NTP server to connect to external NTP servers and sync time in all devices in my corporate network. Below are the contents of my ntp.conf file in the DMZ server server ...
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ntpdate: no server suitable for synchronization found [NO FIREWALL]

I have a private NTP server which again get its time from upstream NTPs and provide ntp service for the LAN. Time of server: Mon Dec 10 12:05:37 CET 2018 Time of client: Mon Dec 10 12:05:37 CET 2018 ...
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1answer
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Prevent VM clock running faster than it should

I have a unRAID 6.6.5 server with perfectly correct time and multiple Linux VMs which used to be perfectly synced too. I rebooted one of my VM and suddenly the clock goes twice as fast as the hwclock. ...
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2answers
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Decentralized NTP in network with only sporadic internet connectivity?

I have a (most of the time) isolated network consisting of several computers. computer 0 -- external NTP server / switch -- computer 1 -- external NTP server \ ...
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1answer
166 views

NTP on a REST API

I have an application that's running a REST API and recently a requirement came up to have an NTP server associated with the application. My question is whether or not it makes sense to have an ...
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1answer
79 views

How do I update my machine time when there is a local ntpd server reference in ntpd.conf

My FreeIPA server's datetime had drifted about 10 min causing login failures. The ntpd service was functioning up and running. I checked the configuration and noticed that freeIPA had added a local ...
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177 views

Behavior when not writing ntp.conf restrict

if I don't write restrict in ntp.conf , so ntp restrict is Unlimited? I wrote: interface ignore wildcard interface listen lo interface listen lan0 man page http://doc.ntp.org/current-stable/accopt....
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Tracking program that sporadically opens ports

On a Debian server I manage, I have a iptables whitelist firewall. For some reason, one process seems to be sending a bunch of unauthorized packets, but I can't seem to identify which one. [1624382....
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3answers
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Ntpd on local network - Preventing clock drift causing high offsets

I have a local network with a microcontroller ARM as the NTP server and I have a desktop computer running with ubuntu 16.04 LTS as a NTP client. Once I start ntpd -g -c /etc/ntp.conf with the ...
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centOs : system time getting reset back to UTC after changing it using timedatectl

I have a Centos machine with version 7. I am trying to change the system time using the timedatectl command. The time gets changed but after a few seconds it gets reset back to it's original time. [...
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CentOS 4.6 Time Drift

I have a CentOS 4.6 box that was previously a physical device, and has been made into a VM, that has a cronjob to restart the server everyday at 23:00. Which is fine. However, since the shift to ...
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1answer
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EventID 1 - An application or system component changed the time

Our VM's are coming up with the following errors in the Event Log - EventID 1 Change Reason: An application or system component changed the time. All the DC's look to be time synced correctly, but ...
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3answers
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How to synchronize time on ESXi Windows virtual machines within one second?

I'm a developer and we are using Quartz.Net, widely used scheduling library with SQL backing store to run cluster of jobs servers (VMs on ESXI cluster). Quartz.Net requires that time will be ...
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NTP does not update until after I poll it

I have NTP setup to run with GPSd and all is well. The issue arises after about a week of my raspberry pi being disconnected, NTP will trust the old date on the system clock. Since the GPS takes a ...
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1answer
252 views

unpredictable high ntp jitter from single local GPS clock source

Question How can I fix transient, high NTP jitter? Background information I have an NTP server on my private network. My servers synchronize from this clock, and usually all is well. An example set ...
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How to be sure that my system time is drifted?

in my some of production environment time is drifted, i install ntp on my system. when i am executing ntpstat command, i can see below output. synchronised to NTP server (169.254.169.123) at ...
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Domain Controller time won't sync with NTP server

I'm having a problem with a domain controller which won't sync with a time server. I've tried everything I can think of and I've already googled many fixes, but nothing seems to work. This is a ...
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481 views

Unable to synchronize date by NTP on Debian 9

Debian 9 as Guest Hyper-V is unable to synchronize the clock and set the right date, always it stays around 6 minutes behind: (Timezone is obfuscated) #  systemctl start ntp #  date sáb jul ...
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1answer
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ntpd -q lists no servers

I am trying to set up ntpd on my servers, so that their clocks are kept in sync. I am running Ubuntu 16.04. I have followed these instructions, and everything seems fine until the end. It's now a ...
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1answer
125 views

Unable to configure NTP on Cisco Switch ws-C3560x-48p

I want to sync time of Cisco Switch (ws-C3560x) with AD server. After following configurations the time is not synchronized. Pl guide. #show running-config | include ntp ntp logging ntp server 150....
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NTP Client sync Error with Server

Can you please let me know if Reference timestamp having difference of more than one day (86400) compared to received timestamp and transmit timestamp, still client will be able to synch with NTP ...
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1answer
324 views

NTP doesn't seem to be enabled and synchronised in Debian Jessie

When I follow steps below in Ubuntu, NTP is enabled and synchronised. However, the case is opposite in Debian Jessie. Anybody knows the reason why Debian says "no"? Also should I worry at all since ...
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NTP 'reach' resetting, wrong refid of remote ntp server, and high jitter

I've got a remote unmanned server that's been exhibiting some extremely strange clock/NTP behavior lately. Symptoms: Very high jitter ntpq -pn returns: A resetting 'when' count of back to 1, even ...
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1answer
43 views

Synch Clock Per Request

I am using CentOS 7.4, and NTP is replaced by Chrony. I just wonder whether Chrony has something similar to ntpdate, which can be used to synch clock per request (from command line, etc)? Thanks in ...
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1answer
206 views

Nagios NTP Time: UNKNOWN: Lookup failure for host $ARG1$ (us.pool.ntp.org)

We are currently utilizing Nagios to monitor our production servers at my workplace. Our Nagios instance is configured on a Linux server where we monitor both Linux and Windows machines. I have been ...
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2answers
343 views

How to do proper VPS timekeeping?

I'm configuring a VPS to log some time-series online data and I notice that the time is off. I'd like to have better than 10 second precision on this. I read somewhere that VPS timekeeping is ...
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2answers
416 views

Find windows process that is changing time back 1 hour

I have a windows machine which will periodically change the system time, for reasons unknown. It appears to happen every hour. This windows machine is a virtual machine (Parallels Desktop 9, Win7 ...
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1answer
1k views

Wrong time on Docker debian container despite NTP

I am creating a simple debian-based docker (php:7-apache). To create it I use: docker run -d -p 80:80 --name myname -v "$PWD":/var/www/html php:7-apache I noticed that my docker is possibly ...
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3answers
1k views

Do “service ntpd restart” and “ntpdate <ntp-server-ip>” do the same work?

I often get large offsets when checking ntpd using ntpq -p, I generally restart the ntp daemon and it fixes the issue. I wanted to know if i can try the ntpdate <ntp-server-name> instead of ...
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1answer
316 views

Azure Time Sync Service without Internet Access

Is there a feature for Azure similar to Amazon Time Sync Service which can be used with Azure VMs to have time synchronization without Internet access? I could also find references to 0.amazon.pool....
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2answers
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How to force locally isolated ntpd update time

Objective I had locally isolated hosts. I'd like them all have the same time. One takes role of the time server, other syncs with it as clients. All machines has sporadic uptime. They are powered ...
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1answer
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Advice on deploying services like NTP, DNS, Radius etc for a small NOC

network engineer here. I recently deployed a small office network and was asked to help out with deployment of some of the services. I have two ESXi servers on my hands and I need to deploy NTP, ...
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458 views

Minimalistic Linux NTP configuration for broadcast server and broadcast client

I would like to have a minimalistic NTP configuration setup for multiple Linux computers that are completely isolated from the Internet, sitting on the same network, which synchronise their clock to ...
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1answer
246 views

W32time on 2016

Virtual server on MS 2016, on a domain, w32time is disabled. What is required so that time sync works with best practice to sync with domain DC? Other MS 2012 R2 have w32time running but manual(...
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2answers
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System time is off by up to hundreds of milliseconds despite NTP sync before boot

I'm running a couple of servers which need a pretty tight time sync (<50ms) as they are running a Paxos algorithm. The servers are running NTP and are successfully sync at one point. According to ...