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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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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195 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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444 views

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
123 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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412 views

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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3answers
362 views

Is there research material on NTP accuracy available? [closed]

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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1answer
882 views

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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1answer
108 views

Less < 10 ms time synchronization solution on Windows [closed]

I am looking for a software / hardware network time synchronization solution. Requirements: Number of nodes ~ 40 The time reading will be performed from a Windows Software (Server 2008 or 2012) ~ ...
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765 views

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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3answers
208 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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196 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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129 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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2answers
1k views

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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3answers
1k views

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 ...
4
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1answer
161 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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2answers
173 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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2answers
143 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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215 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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2answers
1k 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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1answer
121 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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4k views

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 ...
2
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1answer
338 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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1answer
134 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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2answers
179 views

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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160 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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3k views

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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1k views

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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516 views

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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148 views

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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632 views

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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96 views

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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91 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 ...
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117 views

Why running ntpdate one after one dosnt set offset to 0

I am running ntp update , one after one (with sec between them), In the log i see that there is always an offset , even if update was run few sec ago. Why is that?Is there a chance to get 0 offset? ...
2
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1answer
6k views

How to change time source from “Local CMOS Clock” to “DC”

In a domain, I want to set DC as time server. To do that I use this command: w32tm /config /manualpeerlist:europe.pool.ntp.org /syncfromflags:manual /reliable:yes /update and w32tm /resync ...
2
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1answer
106 views

Time jumps on guest system really shortly

I've got a ESXI-Server and a OpenSuse 10.3 distribution running on it as a guest system. In a java (6_17) application that uses Thread.sleep() to not hog 100% CPU, I noticed that it sometimes never ...
2
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1answer
237 views

Time issues on the Network — How to find the Root Cause

A number of application servers started erroring out in my domain. Troubleshooting led me to a missconfiguration of NTP. I fixed the issue, but I don't know how the issue arose in the first place. ...
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657 views

Setting up NTP servers

I have a problem setting up NTP to maintain time on a stand-alone network. This will be an island time-zone. The problem is that the time drifts apart, even after they have been initially ...
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1answer
4k views

Cisco Switch NTP client Clock is unsynchronized, stratum 16, no reference clock

I am trying to configure a cisco switch as a ntp client, however I cannot get past the show ntp status of Clock is unsynchronized, stratum 16, no reference clock. I've tried setting the clock close to ...
2
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2answers
189 views

Crazy VM clock drift

This is taken from an Ubuntu 10.10 VM running on ESX5: Nov 3 21:58:50 server1 ntpd[21169]: adjusting local clock by 31.187370s Nov 3 22:02:36 server1 ntpd[21169]: adjusting local clock by ...
2
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1answer
141 views

When should NTPd broadcast/broadcastclient be used instead of client/server or peer modes?

The NTP deamon if often used in its simplest mode, which is client/server: you specify one or more server directives in your ntp.conf and your clients will use those servers. In addition to that, ...
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1answer
166 views

cannot open shared object file: Permission denied

On a server I haven't installed, ntpd is broken: # /etc/init.d/ntpd start ntpd: error while loading shared libraries: libz.so.1: cannot open shared object file: Permission denied but permissions ...
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244 views

Adjust frequency of Windows Time sync

On Windows 2003 it is possible via the registry to set a custom interval for updates. This is done via the following registry key: ...
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4answers
3k views

ntpdate works, but ntpd can't synchronize

This is in RHEL 5.5. First, ntpdate to the remote host works: $ ntpdate XXX.YYY.4.21 24 Oct 16:01:17 ntpdate[5276]: adjust time server XXX.YYY.4.21 offset 0.027291 sec Second, here are the server ...
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703 views

Setting NTP on Windows 2008 Domain

Our Computers are out by a couple of minutes on the network. I have checked the registry on a computer and found that the type is NT5DS which I believe that it is getting the time from our Domain ...
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758 views

NTP Server with no connection to the internet

I have a small LAN that has no connection to the internet. It consists of two ubuntu servers clustered together providing NFS services to two IP cameras. I need to synchronize the time on all the ...
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1answer
57 views

how to stop all NTP synchronizations [closed]

I think I have made ​​several ntp settings, and make synchronization across multiple servers on different timezones. On my php scripts, date is displayed randmomly for (+2 , +3 timezone ) , for ...
2
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2answers
272 views

Is there any way to make ntpd to iteratively consult the server addresses given in the ntp.conf file?

Suppose the machine has an ntp.conf file that looks like this: driftfile <path-to-drift-file> server <NTP-server-1> server <NTP-server-2> server <NTP-server-2> For some reason, let ...
2
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1answer
504 views

Is my NTP configuration correct?

I have a CentOS virtual machine running remotely, accessible via VPN. It was set up to sync time from two servers on the same network. The time set is approximately right, but seems to be drifting ...
3
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1answer
896 views

Why should I care about NTP Kernel statistics?

I'ved noticed that munin graphs a few bits of information about timing/kernel statistics that I've never quite understood. Most of my servers seem to stay close to 0, which I presume is good, but one ...