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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Windows 7 external NTP

I have a Windows 7 pc that is part of a domain but for research needs it has to be syncronized with a GPS server (not part of the domain). I know that time discrepancy between the domain controller ...
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33 views

Creating a badly behaved NTP server for testing

I'm trying to test behaviour of a server that's configured with a badly behaved NTP server, such as one that's drifting wildly or reporting times that jump around excessively. I've found lots of ...
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What is NTP dispersion and how do I control it?

We roll out Ubuntu 14.04 servers on isolated networks, running ntpd 4.2.6p5, configured to use multiple NTP servers as provided by customers (no access to pool.ntp.org). Our dumb terminal client ...
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29 views

Setting ntp time from gpsd

I'm trying to configure ntpd to source it's time from a gps receiver (BU-353S4) but I'm getting some errors. I'm using ntpd 4.2.8.p6-3 and gpsd 3.16-2 on Arch Linux Arm. I've been following the ...
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58 views

NTP synchronized clock alongside the system clock

Does NTP daemon(ntpd) provide some sort of virtual clock that it disciplines and serves, but not touch the system clock? Goal: On a realtime Linux OS, have a NTP synchronized clock alongside of the ...
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25 views

NTP Service Esxi Vmware

Almost every post I find online has an easy solution for this and I feel I tried them all with no luck. I have a VMware host running ESXi 4.1 and the time is not syncing with my time server. The ...
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36 views

Correcting Time Problems - Cisco Switch - DHCP Options Daylight Savings Time

I inherited quite a network in terms of centralized or correct configuration. The prior administrators did not configure many basic services correctly and myself and my Senior Administrator are now ...
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21 views

configuring ntp server with w32tm

I configure my network with new ntp server to let all nodes sync thier time from it.. before I configure ntp server, entire network was taking their time from PDC. I configure every thing even I ...
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205 views

How do I point clients to the NTP server?

I need to build an NTP server within my network on Windows Server 2012. This server must be dedicated only for NTP. I am using the W32tm service to configure my NTP to resynchronise its time from ...
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41 views

Inconsistent NTP settings on Windows Servers

I'm seeing this odd behaviour on some Windows servers we have: The output of NTP configuration includes these lines: C:\Windows\system32>w32tm /query /configuration NtpClient (Local) Enabled: 1 ...
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45 views

Does NTP should update time after manual change?

I have configured NTP service and I've checked it by the following way: Disable NTP Adjust time Enable NTP Host's time fixed in few seconds. But if I do: Enable NTP Adjust time Time is not ...
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ntp server misconfiguration

PS> w32tm /query /peers #Peers: 4 Peer: 125.23.21.41 State: Active Time Remaining: 904.5625720s Mode: 1 (Symmetric Active) Stratum: 2 (secondary reference - syncd by (S)NTP) PeerPoll Interval: 10 ...
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NTP server in windows 2012 [closed]

I am a bit confused..I installed MS server 2012 on machine and I added it to domain..Over this 2012 server I installed active directory for test purpose.. Then I configured w32tm over domain ...
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36 views

Why are Win 2012R2 virtual machines not in time synch with hyper-v host?

We have a Win 2012R2 server that runs (using hyper-v) 3 Windows 2012R2 VMs. Configuration The hyper-v host is configured to sync its time using NTP with be.pool.ntp.org, see left screenshot The 3 ...
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54 views

How to avoid syncing time with NTP when offset is more than 1000 sec on running system?

We support configuring NTP for time sync in my application.But my webapps are sensitive to sudden time changes. So we wanted to allow time sync with ntp only if the offset is less than 1000sec on ...
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2answers
139 views

How to keep update Hardware clock when server is syncing time with NTP?

Is there any way to sync hardware clock periodically when server is syncing with NTP server? i am using Centos 6.7. Following is my ntp.conf file content # File for including partners custom ntp ...
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18 views

Why does ntpq report reachability (reach) in Octal?

I'm not sure if this is better suited for ServerFault or Stack Overflow. The return of ntpq -p reports "reach" as an 8-bit octal value, 1-377, as in the following example: remote refid ...
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21 views

Is there a way to determine how often Chrony is querying NTP servers to sync time?

Is there any way to tell how often Chrony is querying NTP servers? If the answer is that it uses some algorithm based on how much the server has been out of sync in the past, is there some ...
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69 views

Chrony doesn't appear to be syncing with the servers I've specified

I have set Chrony to sync with 4 NTP servers (config file below). When I run chronyc tracking and chronyc sources, it looks like the servers my machine is connecting to for NTP are not correct. I'd ...
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17 views

Controling NTP drift across my server farm

Good morning, NTP clients were disabled on my server farm awhile back, before I came in. I re-enabled them through puppet and now I get swamped with messages such as Feb 15 06:25:19 *HOSTNAME* ...
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224 views

Ceph: HEALTH_WARN clock skew detected

I have configured ntp on Ceph nodes and time is synchronized! But ceph status always shows clock skew. ceph health detail shows: mon.node2 aadr 192.168.56.102:6789/0 clock skew 7192.45s > max ...
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78 views

Centos 7: ntpstat unsynchronised

I'm setting up a server with a service that is very sensitive to date/time. So I'm trying to configure ntpd but it doesn't seems to work. I'm using the default Centos 7 configuration with the ...
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31 views

MS WS2012 R2 - Integrated NTP client / server

Can WS2012 R2 be configured as a stratum-1 NTP clock source (client to NIST time servers) to which other internal hosts are synchronizing against ... hence NTP client and server functionality ? From ...
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161 views

NTP set up on private AWS subnet within VPC: NTP public server DNS works but not ip, why?

I have a NAT server that's in my VPC's public subnet on AWS. It's pretty happy with its NTP setup so I thought, no problem, let's get all my private subnets using this server as their designated time ...
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150 views

Wrong hardware time on linux

I don't have the correct hardware time on my debian server: root@server[09:48]:date Tue Dec 22 09:48:52 EST 2015 root@server[09:48]:date -u Tue Dec 22 14:48:54 UTC 2015 root@server[09:48]:cat ...
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65 views

NTP server time drifting

We currently do not have NTP (Network Time Protocol) appliance in our environment. So we are using one of server as NTP master server and remaining servers are synced with this using NTP port. Is ...
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88 views

NTP: Linux client won't sync with Win7 server running ntpd ( not w32time)

We have a 'bot with a Linux host running on an internal network connected only to a Win7 host. The Win7 host has internet access, but the Linux host does not. (historical reasons) When I load NTPD ...
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42 views

NTP with Authentication on Windows System

Can we configure NTP Server with Authentication on Windows System i.e Window Server 2008 R2 Standard or Windows 7 Operating System. I need to sync time securely for my Cisco Switch and Router and for ...
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63 views

NTP not syncing automatically with my internal NTP server

I installed ntp on a centos server. I modified /etc/ntp.conf replacing the default server entries with one entry to my internal NTP server's IP (1.2.3.4 is the IP of the NTP server): server 1.2.3.4 ...
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57 views

Different offset in “ntpq -p” and “ntpdate -q”

I'm sometimes notified by our system monitoring about too high offsets in ntpd. When issuing ntpdate, it shows none. As ntpd adjusts time slowly, it seems to "think" there is an offset which needs to ...
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32 views

Windows Domain Network, Cisco 1921 ISR, and NTP

In an effort to make sure all Windows application that rely on time work (such as RDP), and to make sure logging between computers and router are using the same times, I would like to use NTP ...
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24 views

Time servers does not always respond [closed]

I have embedded devices without any OS and I wanted to implement NTP to synchronize time. I have written some C program to test NTP on Linux (I send ntp datagrams to time server with different time ...
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NTP: How to establish redundant solution for NTP servers?

In my company's infrastructure there are 5 data centers in remote locations. In each remote location, there's a pair of servers which hold DNS and NTP services and are configured on each one of the ...
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Domain server sync NTP is now 4 mins faster

We activated the sync time with external NTP (0.north-america.pool.ntp.org, 1.north-america.pool.ntp.org) on the DC for quite a while, and lately the synchronized time is now abt 4 mins faster than ...
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Does a Windows 2012 NTP server need an upstream NTP time source

I have a set of 3 Windows 2012 Server VMs running as my domain controllers. These VMs are in an air-gap environment, meaning no access to upstream NTP servers. I haven't been able to configure my ...
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39 views

Yosemite 10.10.5 Clock drifts while asleep

We have a cart of Macbook Pros with Yosemite 10.10.5 installed on them. Our school network uses 802.1x for authentication to the WiFi, but when these laptops are put in their carts and left to sit ...
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Is it possible for NTP to have two system peers at the same time?

In some rare cases, ntpq -p reports here that it has two system peers, like this (IPs and results anonymized): remote refid st t when poll reach delay offset disp ...
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109 views

Windows server time keeps setting the time 2 hours back

Our Windows 2012 server keeps setting its system clock 2 hours back. I've tried to run 'w32tm /resync' a couple of times but that does only works on short term. the server manager gives an Error ...
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353 views

How to fix time on NTP server with a lot of machines synchronized by it

I have one NTP server which has a wrong time setting which are 7 hours in the future (timezone was changed after machine shipment, but not the time). The server itself is not synchronized, but only ...
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146 views

AWS - ELB - NTP - Unable to forward UDP Traffic?

I am trying to setup two micro-instances behind an internal ELB which will handle mundane tasks such as central logging and NTP queries, but come to realize that ELB doesn't support UDP forwarding. ...
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1answer
69 views

Configuring Windows Times Service for non-PDC emulator

Not to get to deep into the weeds, here's the gist. A SysAdmin of ours created GPOs on the Domain Controllers Policy (DCP) and we've been having time issues ever since. Neither he nor I know if the ...
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87 views

Is it possible to increase the rate at which ntpd updates the system clock?

We have some hosts that have gotten out of sync due to ntpd being mis-configured, with an ntp server that was unreachable. Our clocks on some hosts (CentOS 6) are now upwards of 30 seconds off (in the ...
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2answers
37 views

How do I query a Domain Controlers NTP service from a linux box?

I need to confirm that a Domain Controller is acting as a NTP time server for non windows devices and servers. I figure there must be a command in linux that will query an NTP server and see if it is ...
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35 views

Securing my NTP configuration

Need some assistance configuring my ntp.conf file for my primary NTP server. Does my configuration accomplish the following: Prevent the servers being polled from changing my configuration? Allow ...
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76 views

ntpdate on ec2: no server suitable for sychronization

I'm trying to turn NTP on for a handful of EC2 instances inside a VPC, starting with ntpdate, since my server is pretty far off and I don't want it to slew. I'm running into the 'no server suitable ...
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559 views

Windows 2012 R2 NTP server Unable to sync with Cisco Nexus

I am the PDC Admin, The Windows NTP server is set correctly, we have 5 different time sources set. We are able to sync with 2 of those time sources and other external time sources such as ntp.org ...
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How accurate can we get computer clocks synchronized in a local network of any number of computers?

In the past, I have seen that most of my computer on my local network don't really have the same time within up to 1 second or so. So I wanted to make sure that it would be possible for a stack of ...
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Why is the NTP local fudge server no longer reachable?

For many years I have had: server 127.127.1.0 # local clock fudge 127.127.1.0 stratum 10 In my /etc/ntp.conf configs - it always worked as I expected it to: ie. was mostly useless but for those ...
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467 views

NTP: Should I configure NTP step-tickers in a domain which uses local NTP servers?

I've bumped into something which is called "NTP step tickers" and read about it in this article, but I'm not sure if it's required in a domain which includes local NTP servers. It seems like it ...
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539 views

Best choice for NTP client configuration

Lets see if someone can throw a bit of light on this subject.. I'm making a server installation in the next days. My client wants to deploy a Hortonworks HDP with 2 servers as master servers and 5 ...