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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Time sync on non-domain joined servers

I have a server which is in a workgroup in a separate network from the rest of the domain. As a result, it cannot use the domain controllers as a time source. The server is a Windows Server 2012 R2 ...
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Is it possible to run ntpd with a time that is intentionally distinct from system time? [duplicate]

For example, could I set the ntpd time five minutes ahead of the system time? I know I can set the time manually without running (or even installing) ntpd, but it's not obvious to me how to run ntpd ...
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Changing timezone in all the servers of a cluster: unexpected side-effects to consider

We want to change the timezone of a cluster of Ubuntu machines from PT to UTC (so we move a few hours into the future). The change would be done by changing the servers in the /etc/ntp.conf file (...
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How to fix the date which is off by years

My server is in the future 2027: # sudo ntpdate ptbtime1.ptb.de 9 Jul 00:04:01 ntpdate[10000]: step time server 192.53.103.108 offset -353547847.989546 sec # date Di 21. Sep 23:48:18 CEST 2027 # ...
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Allow Active Directory users to disable datetime sync

I have recently migrated my company to Active Directory. With it comes a default setting that will force time synchronization to be enabled. Trouble is, some users need to change their datetime ...
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Dealing with NTP reflection attacks in IPTables

We're dealing with an NTP reflection / amplification attack at our colocated servers. This question is specific to responding to NTP reflection attacks, and not directed at DDoS in general. Here's ...
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37 views

Unable to find the root cause of ntp configuration error

I am trying to configure ntp to synchronize the time of my server. When I run ntpdate -dq 1.rhel.pool.ntp.org I got the following error. no server suitable for synchronization found I am on ...
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36 views

How to set up NTP (not SNTP) on a Windows box?

I have a network that is running on Brocade layer 3 switches. I need these switches to be synced with NTP. The computer that I need to use is running Windows 7 and has services such as Win32time ...
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23 views

ntpd appears to work with ipv6 servers, but not ipv4

So, we have an ntp server (ntp-4.2.8-r1) which uses this list of time servers: server pool.ntp.org server 24.56.178.140 server 2001:470:0:2c8::2 server ntp.markyate.net server ntpv6.dianacht.de ...
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Configuring NTP server on a virtual machine and have it point to the physical machine

I have a virtual machine running on a physical machine, both using RHEL 7/CentOS 7. I need to configure the virtual machine to serve as an NTP Server and have this NTP server point to the physical ...
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29 views

How to compare the times of two servers?

In order to match logs from two unrelated servers (in different companies) I need to account for the possible time difference between them. We can assume that they both run ntp which point to pool....
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77 views

Windows 7 PCs in a domain - time source keeps changing

I need help figuring out why the time source on some PCs keeps changing. Right now they're on Local CMOS clock. If I do w32tm /config /syncfromflags:domhier /update net stop w32time net start ...
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55 views

Getting an error when trying to start the “ntpdate.service” for RHEL7.1

I am trying to restart services for openstack, and under my /etc/systemd/system/multi-user.target.wants/ I run a systemctl start ntpdate.service and get the following error: May 31 12:05:39 ...
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What is Best Practices for time management in RHEL/CentOS 7 in VMware?

NTP, CHRONY, OPEN-vm-tools... Best Practices for time management in RHEL/CentOS 7? Hello. I am (finally) working on creating a CentOS 7 VMware (ESXi) Template - currently ESXi/vCenter 5.5+. Past ...
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51 views

VMware 5.5 Host Not Updating Time From NTP

I have 2 HP ProLiant VMware 5.5 hosts and I have configured the time sync on them to use NTP. I have pointed the NTP to the n.north-america.pool.ntp.org servers. I have restarted the time service ...
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166 views

How come one of my switches is off by two minutes in spite of ntp?

I just noticed by pure chance that one of my Cisco 4500 switches has its clock going wrong: it is more than 2 minutes behind in spite of seemingly functional ntp. In my opinion, even a single second ...
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31 views

ec2 instance time drift

Recently I've encountered 2 instances which are in a VPC that have time drifted issue. What I've noticed is that the time servers does not have * and + prefix compared to another instance with ...
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68 views

Where can I see ntpd working status (log or message)

In my server the ntpd service is started but it does not seem to work. I can find nothing according to this ( Where are the ntpd log file located, and how can we configure the ntpd log file path? ) ...
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38 views

Can i set a same NTP server twice by using IPv4 and then IPv6 address of the same server

can I set same NTP server twice i.e one by using IPv4 address and other by using Ipv6 address of the same NTP server? for example : lets suppose we have a NTP server named as XXX. Now this XXX ...
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109 views

How can I synchronize system time with a NTP server continuously?

Is there a linux service that can synchronize system time with a NTP server with a given interval, such as 1 minute, 1 hour or 1 day ? Is it a good practice to run utpdate in a cron tab? e.g. */10 * ...
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49 views

Ntpdate is not running on my machine

I am trying to give IPv6 support for NTP server in my ntp scripts. Yet i have set the IPv6 NTP server directly by giving its IP in ntp.conf and restart the ntpd . Now in the logs of ntpq flash ...
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50 views

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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58 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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70 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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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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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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80 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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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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216 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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59 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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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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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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110 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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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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19 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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39 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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276 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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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* xntpd[...
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874 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 0....
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125 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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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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398 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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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 /etc/...
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135 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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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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101 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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111 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 ...