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Questions tagged [ntp]

Network Time Protocol, used to synchronize clocks on the Internet.

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9 views

Meinberg NTPD for Windows timeouts and not finding files

In my network, I have a reliable NTP server which all PCs are synchronized to. Due to the various problems the Windows Time service is known for (at least in Windows 7 and lower versions), I have ...
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21 views

Is anyone tried ntp with restrict default nopeer command [on hold]

NTP version installed: ntp-4.2.6p5-5 I'm trying to understand the usage of below ntp restrict command : ----> restrict default nopeer Below is the reference info shared in ntp documentation: http://...
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13 views

How to make a local linux machine as NTP server (other local machines will use this as the server) and this machine will sync time from another server

I have a local linux machine say of ip 172.16.. , and this machine will be synching time from another central server . Just wanted to use the machine 172.16.. , as the internal ntp source for other ...
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1answer
124 views

Managed Switch (HP 1820) doesn't synchonise time with NTP Server

I'm trying to set up a managed switch (HP 1820). So far everything works, but the time doesn't synchronise. The switch is configured correctly in terms of the IP-Settings (IP/Sub/Gateway - no DNS ...
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34 views

Time synchronisation. ntp cannot use any peer

`ntpq -p -n' gives me remote refid st t when poll reach delay offset jitter ============================================================================== 10.11.12.1 10.11....
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18 views

Programmatically log all NTP time adjusting events

How to catch all the time sync events on system with systemd? Is it possible using D-Bus? Now I can only parse logs (journalctl -u systemd-timesyncd) -- I don't like this method. I cannot find any ...
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1answer
161 views

Windows Server and AD - Disable time sync on logon

I have a MS AD domain with some application servers all running Windows Server 2012 R2. The application has a special requirements: time shift between its database and the app servers must be less ...
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1answer
56 views

Configure Rapberry Pi to take time from Windows PC

I have a Raspberry Pi and Windows 10 machine, they will be connect directly via RJ45 and on the same subnet so they can communicate. They will both be completely offline with no access internet access,...
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97 views

NTP is not syncing with an external time server

I'm trying to sync with an external NTP (pool.ntp.org), but the server is responding with this message: This is the Wireshark capture. Network Time Protocol (NTP Version 3, client) Flags: 0xdb, Leap ...
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137 views

Active Directory client PC unable to sync time from server

I am running Active Directory on a Windows Server 2016 VM. The server is syncing via NTP with an external source and other PCs on the network are syncing time correctly with the server but I have one ...
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368 views

instantaneously sync time via NTP after large offset on win10

One of my Win10 machines has a large time offset, in the order to weeks (its a VM that gets unpaused on request). In the age of short-lived SSL certificates, it is crucial for many (web-based) ...
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115 views

MITM redirecting to my own NTP server, blocking traffic to Apple NTP pool

CONFIGURATIONS ipv4.forwarding 1 (ON) arp_cache_poisoning between VICTIM & D.G.. (192.168.1.100 & 192.168.1.1) **LAN** VICTIM: 192.168.1.100 ATTACKER: ...
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722 views

What is Windows's time server synchronisation precision? (and does it compensate the ping time?)

For the project described in Application of this question I need the best time clock precision possible, and one solution is to have a precise synchronisation of the computer's real time clock. What ...
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102 views

NTP with SHA256 authentication

As a part of FIPS certification, I need to support SHA256 authentication between NTP client and server. I found NTP documents for SHA1 and MD5 symmetric key authentication using ntp.keys and ntp.conf ...
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19 views

Ubuntu: how to check when system clock was adjusted

I'm trying to figure out when the ntpd adjusted the system clock on Ubuntu 17.10. The ntpq -pn utility shows when the client synchronized with the server last. But it doesn't show when it desided to ...
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59 views

NTP synchronization on win10 pro x64

I'm trying to find how to set up on Windows 10 Pro time synchronization from three different NTP servers as on the picture. I have three time sources - two with a GPS signal and one DCF77 source. ...
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34 views

how to upgrade ntp in SUSE SP11?

I want to upgrade ntp client version to 4.2.8p9 or later for SUSE 11 SP4 Enterprise. what are the steps to upgrade to mentioned version? I have this patch: ntp-4.2.8p9-27.1.x86_64.rpm Do I need to ...
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1answer
80 views

Time sync with NTP on Vmware Fusion VM

I built a Centos 6.9 VM in VMware Fusion with Synchronize Time turned off and I followed this doc: https://kb.vmware.com/s/article/1006427?sliceId=1&dialogID=373948728&docTypeID=DT_KB_1_1&...
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14 views

MSYS: syncing local time with NTP

I have a Win10/MSYS2 installation on a VM. The VM is mostly "suspended" (paused via the hypervisor). So when the VM is unpaused it has the wrong time (from before the pause). The idea is to run a ...
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246 views

ntp sync issue after setting time with date command

one of our servers had not accessed the time server for a long time. After access is turned on; my colleague has notice date is wrong and setting time with date command. After this I have restarted ...
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62 views

How can I use my local time as the only reference of `ntpd`?

I want to let my Linux device synchronize its local time with the local time of another Linux server without any other references. I don't care about the actual time. I want my fake time. Therefore I ...
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1answer
193 views

Avoid dhclient-script overide ntp on amazon linux ami

We're using emr cluster on amazon webservices 'aws'. We are using default 'Amazon Linux AMI' images without customization. It looks to me that the dhclient-script is fetching configurations from our ...
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1answer
833 views

How to use secure NTP authentication from Windows client to a Linux Server?

I have a NTP Server running on a Linux (Ubuntu 16.04) box and I also have to securely serve a bunch of Windows Server boxes (2012, 2012 R2 and 2008 R2 mainly). For network equipements and Linux ...
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2answers
217 views

How to configure NTP over cross-over cable?

I'm fairly new to NTP. I have two computers running Lubuntu 17.04 that I'd like to keep in close time sync with minimal hardware. There is no need to sync to real time, just to keep the system times ...
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1answer
863 views

New managed Netgear switch won't sync to time server (stays on “local” not “SNTP”). What settings should I be using?

This is nuts, I know. But I cannot get my new Netgear switch, to pick up the time from the time server used on the LAN. I've tried both CLI and GUI, I can't work out what it needs. The LAN has a ...
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0answers
213 views

How to configure the local RHEL server as NTP Server

I am trying to configure local RHEL server as NTP Server. But the "ntpstat" showing unsynchronised. Local host ip address : 192.168.1.122 /etc/ntp.conf server 192.168.1.122 prefer # local clock ...
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1answer
3k views

Unable to synchronize Windows time with local NTP server

I have installed NTP server on a machine in LAN (pfSense), unfortunately, Windows can't synhronize time with it Why and how to fix?
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967 views

Windows Server 2012 R2 PDC has no internet time tab

Clients on our domain get their time from the PDC, but the time on the PDC keeps on drifting forward about 5 minutes every few days. All the solutions I search say to log on to the PDC and change the ...
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1answer
811 views

clockdiff versus ntpdate -q

I want to know the time difference between the clocks on two different hosts. I've found clockdiff and ntpdate -q both perform similar functions. Please provide some insight on the difference between ...
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87 views

Systematical -1.35s offset after NTP sync

Running Windows 10 build 15063 on a Lenovo X220i tablet laptop, I have tried synchronizing against a number NTP servers including time.windows.com, se.pool.ntp.org, ntp.se, time.nist.gov, and a local ...
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124 views

Why does server time goes behind than ntp server?

Suddenly one of my Linux VM is two minutes behind than the ntp server. I restarted NTP and it got fixed. I should have run ntpq -p before restarting. :-/ 10 days ago it became 2 minutes behind, ...
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1answer
6k views

Windows Time not synchronizing - “Access is denied” error

My Windows 7 computer's time drifts every time I reboot, and resynchronizes either not at all or sporadically. When I go to Date and Time > Internet Time > Change settings... and click Update now, I ...
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341 views

Is there solution for Windows Server to use MD5 certificate NTP source validation/authentication?

Is there a built-in or third party solution for Windows Server to use MD5 certificate NTP source validation/authentication? If it is built-in, what version of Windows Server and what is the feature ...
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129 views

ntp client does not work with DD-wrt using PPPOE as wan

ntp client does not work with DD-wrt using PPPOE as wan tried different firmwares, facotory resets, different routers cant get it to wrk.. works fine with 2009 firmware on wrt54g (works with default ...
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392 views

How to query a NTP server without root?

People are saying ntpdate is deprecated and I should use ntpd. But how can I run ntpd to simply query a NTP server without root?
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1answer
114 views

Are ntpd and ntpdate both being run on my system?

I have a computer running ubuntu 14.04. I am running a process that is sensitive to time jumps, and I have noticed some time jumps have happened, on the order of 100s of milliseconds both forwards ...
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2answers
1k views

Setting up NTP service to Automatic restart

Setting up NTP service to Automatic restart which one should set to on in given list ntpd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
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2answers
261 views

Synchronize the time of two PCs using pool.ntp.org

I am synchronizing the time of two PCs (for some network latency experiment). I know NTP Pool Time Servers can also do this job for ubuntu. (Of course, some software like NetTime works on Windows.). ...
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1answer
256 views

Why can I see no evidence of a leap second, during this simulation?

I'm trying to simulate the forthcoming leap second so that I can test my application's behaviour around that time, but I'm not convinced I'm setting up the test properly. On CentOS 7.2.1511 inside an ...
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1answer
160 views

Sync the clock of a Linux embedded device with a PC

I have an embedded device running Ubuntu 14 and I want to sync its clock. The problem is that the device does not have internet and the setup is like this: The embedded device is connected to a PC ...
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131 views

Determining default qualification thresholds for ntpstat

I have been looking into the ntpstat command, more specifically how it determines whether or not the clock is synchronized. From the man page, I see the following excerpt: ntpstat returns 0 if clock ...
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2answers
706 views

can i change the polling frequency of a running ntpd?

I've got ntpd running. It's been running for a while, and the polling frequency is up to the max of 1024 remote refid st t when poll reach delay offset jitter ===============...
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1answer
350 views

NTP-client won't start with DHCPCD

The ntp-client service fails to start upon boot with a dynamic IP due to a name resolution problem. The server can be started upon boot completion manually and works fine. This is happening on ...
2
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1answer
534 views

Raspberry Pi 3 clock won't sync after reboot

I have a Raspberry Pi 3 running Gentoo and the clock doesn't sync with NTP after a reboot. Once the system comes up again it restores the last recorded time from swclock. I have to start the ntp-...
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2answers
17k views

w32time: The computer did not resync because no time data was available

I am using Windows Time Service to synchronize the time between two machines in a network. The network is isolated and it doesn't have internet connectivity. I configure one of the machines in the ...
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1answer
807 views

OpenNTPD complains about an empty drift file on archlinux

I have a fresh install of OpenNTP (openntpd 6.0p1-1) with this uncommented part in /etc/ntpd.conf: servers 0.fr.pool.ntp.org servers 1.fr.pool.ntp.org servers 2.fr.pool.ntp.org servers 3.fr.pool.ntp....
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2answers
619 views

Why is my machine's time drifting so quickly?

I have an Ubuntu 14.04.4 LTS VM running under Vagrant and VirtualBox. When comparing its time to the server's I see things like this: $ ntpdate -q ntp.ubuntu.com server 91.189.94.4, stratum 2, offset ...
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1answer
459 views

Synchronising Linux host to NTP Server

I'm trying to synchronize the time of Linux host with NTP server. The configuration file is modified with server information and the NTP service is started using the command service ntpd start By ...
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2answers
41 views

Are there any NTP servers online which let machines sync to a different time (even years)? [closed]

I want to sync virtual machine (XP client on Virtualbox) to a time other than the host machine.
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1answer
1k views

Apple Devices, NTP-Requests?

Our DHCP delivers the address of an internal (working) NTP-Server. However our firewall reports a "massive" Storm of NTP-Requests (from iPhones, iPads) trying to contact some server on the internet. (...