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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Ubuntu 12.04 LTS regularly loses sync with NTP server

I have a Ubuntu 12.04 LTS VM running inside VirtualBox. It is fine except the clock winds up being exactly 25 minutes behind every other machine on the network. My normal procedure is to setup NTP, ...
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446 views

NTP synchronisation not visible in syslog

I am trying to set up a local NTP server for our LAN. I am able run ntpdate server_ip to manually update the time. However, ntp daemon does not seem to be logging anything into syslog, and so I can't ...
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What are the disadvantages of disabling tinker panic 0 in NTP?

We sometimes have the problem that new servers have the wrong time in the bios, so there time can be off by a month. When you suspend a VM in VMware and then unsuspend it, the time will be off too. ...
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How to make NTP work despite a high offset?

Recently I have kickstarted some servers that had their time off by a month in the bios. The time in the bios said it was a random time/date in May, while it was June. This caused NTP not to work, ...
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Set up an NTP server to allow local machines to be syncronised for Linux

I am trying to set up a machine to act as an ntp server to which the other local machines will syncronise their times to. This needs to happen regardless of whether the ntp server machine is connected ...
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What is the strategy for detecting time drift in a linux based data centre?

What is the strategy for detecting time drift in all linux based data centre? This is a more difficult problem than it seems at first. Time drift can cause serious problems for certain applications ...
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220 views

Clock skew on my VPS server

I am having a problem with the time on my VPS hosted at Rackspace. Its running Red Hat Enterprise Linux 5.4. Date commands gives a time which is 11 minutes ahead of the actual time. I am running ntpd ...
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61 views

Debian Server System time and time used by processes are different

I have a dedicated server running debian 7, the system time shows "Wed Aug 7 04:28:26 EAT 2013" I have restarted the server several times but processes like deluge and apache return http headers ...
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enable/disable ntp service on ubuntu 12.04

Our application runs on Ubuntu 12.04 Precise. On this server, we have both ntpdate and ntp. How to enable and disable the NTP service on-demand? I tried # sudo update-rc.d -f ntp remove/default ...
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58 views

Pinpointing source of clock inaccuracy

I am having a huge problem with the clock on a Windows XP machine. Whether getting its time from the domain controller using w32time and an ntp server (PDC) / client, from a GPS clock directly using ...
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2k views

Why not use vmware tools for time synchronisation?

We have two VMWare environments running a bunch of (mainly) Redhat 5.9 and 6.4 guests. We are having issues with time drift (minutes ahead per week). We use ntp, syncing to the local domain ...
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ntp.conf being rewritten in Fedora

Something rewrites my ntp.conf on reboot. It's easy to google that DHCP client may do it, and there is a simple solution for that. Just including -N option into dhcpcd_eth in /etc/conf.d/net should be ...
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198 views

Meinberg NTP Client large wandering

All, One of the computers on my network runs Windows Embedded Standard and is running the meinberg NTP client and gets its time directly from a GPS clock. The service is set to run automatically and ...
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1answer
355 views

Failed to install ntp via apt-get in Debian

When trying to install ntp (because my server clock is wrong), it just pukes this massive error. Any idea how to fix this? root@pan-prodweb01:~# apt-get install ntp Reading package lists... Done ...
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365 views

compile ntp without ssl

I need to deploy ntp to a very space-critical pxe-imaging-system. (Yes, each KB matters.) Footprint needs to be as small as possible, so I want to compile ntp without linking openssl. According to the ...
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553 views

Discovering NTP servers providing time service on network

As a linux (Debian-based) host on a network, how can I discover whether an NTP service exists somewhere locally on the network? Thanks.
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371 views

How to clear/flush ntp server peer in Centos

We were using centos.pool.ntp.org for our clock sync among servers. Now we do ave a local NTP server, but the problem is servers are using the old ntp. From centos.pool.ntp.org we can see, ...
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Wrong time on my Ubuntu Amazon EC2 instances

I have three Ubuntu EC2 instances on Amazon AWS (EU/Ireland), all set up as web server. I noticed the system date/time is incorrect in two of them (timezone is always set to UTC for my choice). Here ...
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130 views

NTPD keep using UTC

What I'm trying to do with NTPD is syncronize all of our switches (3Com Baseline Switch 2928-PWR Plus) but instead of getting the localtime, they get UTC time. The time in the server works well, the ...
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268 views

Time Synchronisation of Virtual Machines without connecting to the Internet

I have a setup of 8 VMWare VMs running across 4 EXSi hosts(IBM Blade Server). For some reasons I cannot connect these VMs or the EXSi hosts to the Internet or any other network. Now I want to ...
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Manually syncing comp clock with DC works, but after a minute - clock incorrect by 5 minutes

The problem: DC1 Clock: 17:23 AD joined client clock: 17:28 After client> w32tm /resync time is in sync, but the clock again jumps forward for 5 minutes for client. It always happens in less ...
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1answer
355 views

NTP synchronization stays with no reach

Usually, when a machine looses connection completely, ntpd misses a couple polls and marks all sources as failed sanity. Which seems quite logical. But I've met a situation when a server stays marked ...
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Xen: synchronizing time with Dom0

I have Xen virtual machines running on Debian 6 (both Dom0 and DomU). I would like to synchronize clock on DomU with Dom0. On http://wiki.xen.org/wiki/Xen_FAQ_DomU I have read that I need to set ...
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Is there research material on NTP accuracy available?

As far as I know, accuracy of NTP syncronization highly depends on the network. I've seen some numbers from 50 microseconds to a "below one second" over the internet. Well, this is a huge difference. ...
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NTP can't synchronise or find a suitable server

The problem I'm trying to solve is that NTP won't synchronize: $ sudo ntpstat unsynchronised time server re-starting polling server every 64 s Edit: Here's some ntpq output: $ sudo ntpq -c ...
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Nagios: check services being orphaned?

Recently I noticed that there are some warnings in the nagios.log: [1366060611] Warning: The check of service 'pt-deadlock-logger' on host 'xx' looks like it was orphaned (results never came back). ...
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543 views

CentOS VM, NTP synchronization problems

We have three CentOS 5.9 VMs on an ESX3.5 host. Because of the nature of the services we provide it is required that the NTP time is synchronized and the time is correct on all three of them. ...
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590 views

ntpdate wrong date

Hi all I have an ubuntu8 server where I have problems with date. My current date (Europe/Rome) is 9:35 If I do date print me 11:12:34 I have seen my ntp.conf is: server 0.ubuntu.pool.ntp.org ...
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222 views

Syncing with ntp server in linux using ntpdc query

I am using ntpserver version ntpd – NTP daemon program – Ver. 4.2.4p4 in linux box. I want to sync to a ntp server using ntpdc query. Is that possible ? If yes, then how do I do it? I tried it using ...
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Is it viable to use w32tm /stripchart to judge time variance of two Windows hosts from each other? A better way to discover two host's time variance?

Is it viable to use w32tm.exe's option stripchart to judge the time variance of two hosts (within a very small margin of error)? Note that w32tm.exe's stripchart function is separate than the ...
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Do I need to run a NTP server in every VM?

Couldn't the guests somehow inherit the system time of the host ? It seems kind of pointless to run the same daemon to get the same results on the same machine multiple times but I didn't find ...
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215 views

Routers do not Synchronize Clock using NTP

I have three Cisco routers connected as shown in the diagram. The problem is, while R1 is synchronizing the clock using NTP, R2 and R3 are not. All the three routers have been configured for NTP ...
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398 views

using NTP protocol for internal time synchronisation

I have two embedded system that are connected via ethernet. I want them to run synchronously. Using NTP protocol is an option to synchronize them. But this is a isolated system. I don't have an ...
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406 views

Ntpd excessively inaccurate

I have ntpd set up (Meinberg ntp-4.2.6p5@london version for Windows on a Windows 7 client) with a bunch of nearby servers selected for low ping times (usually 10-20ms ping). However it seems my clock ...
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421 views

Real-time clock is wrong (from hours to years), one-time non-monotonic change at boot needed. Can Chrony solve this?

I can't guarantee a sane real-time clock on some machines (the time might be wrong by hours, months or even years). Since I also have intermittent networking, I set up Chrony in the hopes it could fix ...
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4k views

Setup of NTP on Hyper-V servers

I am having problems with NTP setup on our Hyper-V host and clients. I am not using Domain Controller (almost all advise is given for DC's which I am not using). On all servers I have used the ...
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319 views

w32tm /query /configuration equivalent in 2003?

I'm trying to figure out the NTP server in use, so I issued w32tm /query /configuration But that doesn't work, Looks like /configuration is invalid in 2003, what's a possible substitute?
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Why is NTP syncing to LOCAL rather than remote server?

So, I'm trying to debug my current NTP setup, and found that he offset from my single configured server is over 3 seconds, and not adjusting. The asterisk on the LOCAL(0) in the ntpq output seems to ...
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1answer
645 views

ntp offset is growing after some time

I have 10 clients and one server syncing with 2 NTP servers on windows using Meinberg NTP, all of them running Windows XP SP3. Except the server all of them syncing their time perfectly. The one that ...
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143 views

Since today morning one of the DC's in my workplace changed it's hour to 2 hours late and I'm unable to find why

The server is getting NTP updates from a Linux server in the environment: C:\Windows\system32>w32tm /config /update The command completed successfully. C:\Windows\system32>w32tm /query /status ...
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NTP server hostname validation regex [closed]

I want make basic syntax validation of NTP server hostnames. (For example, I expect %^$&" is a syntaxticly invalid NTP server hostname.) The reason I want to make this basic validation is because ...
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Why does ntpd listen on so many ports/addresses?

I’ve noticed this for a while, and it’s never made any sense to me: Why does ntpd need to listen on so many addresses? For example, a Debian machine: $ netstat Proto Local Address Foreign Address ...
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192 views

Using meinberg ntp over 40Km wireless network

We have a network of 10 clients running Windows XP with meinberg ntp. Clients are syncing with two ntp servers over a 40Km wireless network using mikrotik devices. Some of clients are connecting to ...
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ntpdate and ntpd failing to sync clock on Linux

I have a strange problem with one of my servers. ntpd and ntpdate fail to work, but debugging shows no errors at all. At first I thought maybe a local or network firewall was blocking UDP port 123, ...
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Setting Shoretel phone time correctly with dhcpd

Our Shoretel 230 phones are not picking up time service correctly and thus, the time on the display is wrong. When I go to the diagnostics of the phone, they are using a wrong time server (old). Here ...
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NTP configuration in NEXUS Switch

I'm planning to change the NTP peer to 172.29.100.44, but I'm unable to delete the existing and add new peer NTP peer IP in Nexus switch. Could you please suggest how I can remove the existing ...
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NTP syncs with local timeserver but not NTP pool servers

I setup an NTP server on a machine in another subnet and tried to ync my machine with the server and it works well. But when I try to ust the pool.ntp.org servers (I tried 0.pool.ntp.org, ...
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Does a Juniper SSG work well as an NTP server?

I have an old SSG-140 that I wanted to use as an NTP server for a number of devices - is this device able to act as a stable NTP time source? My Linux clients can't seem to stay synced to the device ...
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NTP devices - Meinberg etc

I am learning about NTP & I was wondering why anyone would buy a Separate Device like the time servers/devices available from Meinberg etc? Can you not run some software which syncs with reputed ...
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120 views

Need one time server clock sync for latency test, what should i use ntdate or ntpd

All machines are Ubuntu I need to sync clock one time for all machine in order to do a latency test. I read this article that said - ntpdate is a bit of a blunt instrument - it can only adjust ...