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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Is an ntpdate correction atomic?

I've got the following in /var/log/syslog, from yesterday (July 30th) Dec 16 22:54:05 omap ntpdate[432]: step time server 91.189.94.4 offset 12052648.821465 sec ntpdate 91.189.94.4 "corrected" my ...
2
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1answer
303 views

NTP: ntpdate to sync time between the cp's on private network

I have two systems One acts as Primary/Active and has Internet connection and gets time from NTP server. The second system is Secondary/Passive and has no connection to the external world. Primary ...
1
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1answer
104 views

How does a replicated DC handles w32tm changes?

We have 2 replicated W2K8R2 DC's. I had updated one (DC1) with w32tm to get manual updates from asia NTP. Everything syncs correctly. My question: (In order to learn): How does this propagates to ...
2
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1answer
379 views

Link CentOS server to an NTP Server

I have a CentOS 5.5 server that the clock is wrong on. I also have a pre-existing NTP server, but all of the info I can find is focused on setting up an NTP server, as opposed to linking to one. How ...
7
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1answer
2k views

Single NTP server on isolate network

I have two linux machines (A and B) on an isolated network. They must be time-synchronized. Machine A is powered intermittently and must serve the time, as it is connected to an authoritative time ...
1
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2answers
3k views

Cisco ASA5505 won't sync with NTP

Today I noticed that the clock my Cisco ASA 5505 firewall was running about 15 minutes late, which surprised me since I've set up the NTP client. My two NTP servers 10.10.0.1 and 10.10.0.2 are ...
2
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5answers
2k views

Does CentOS 5.4 properly handle leap seconds?

Apparently the IERS have announced a leap second due at midnight, June 30th this year. Is CentOS/RHEL 5.4 properly updated to support/transition along with updated NTP systems? I was under the ...
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2answers
212 views

Is ntp.ubuntu.com redundant?

Does anybody know if Ubuntu's NTP servers are redundant? If I dig them, I get: ;; ANSWER SECTION: ntp.ubuntu.com. 280 IN A 91.189.94.4 vs. when I dig pool.ntp.org: ;; ANSWER SECTION: ...
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1answer
2k views

ntpd doesn't seem to sync at all

I am following this tutorial It's 2008, so I am very careful using its advice. I need to make this machine the master, and let all other machines use it to sync the time. They are all out of sync by ...
5
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2answers
1k views

What is a realistic average time difference between servers in the same LAN?

Until recently, we had at work a small cluster of about 20 small Windows servers (which have now all been virtualized). They were all configured to synchronize with the local time server. It was on an ...
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1answer
338 views

does NTP minpoll-maxpoll control sync intervals?

Do the NTP minpoll and maxpoll configuration attributes control the sync interval or do they only control the polling interval? where: polling = messaging with NTP servers to estimate the offset ...
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1answer
946 views

NTP maxpoll limits

Regarding NTP's maxpoll configuration attribute, many resources state: The maximum poll interval defaults to 10 (1,024 s), but can be increased by the maxpoll option to an upper limit of 17 ...
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2answers
10k views

Windows 7 as NTP Time Server

Trying to get Windows 7 box to act as an NTP Time Server for linux clients From here: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\ In the right pane, right-click ...
2
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2answers
5k views

NTP not updating the server time in CentOS

I compiled ntp for arm My NTP client is not updating the time from any of the server I referred to the post "Why is ntpd not updating the time on my server? (7)" But nothing works out.. Here is the ...
2
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2answers
277 views

How often does asymmetric latency actually happen?

I was reading through the Wikipedia entry on NTP, and noticed this: The NTP synchronization is correct when both the incoming and outgoing routes between the client and the server have ...
1
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1answer
536 views

Windows Server 2008 R2 NTP ignoring SpecialPollInterval

I've pointed the 2k8 machine to the NTP server and it updates fine on the original bootup. But I want it to update every 30 seconds. It's for a practical and I have to show NTP in action. It keeps ...
0
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1answer
191 views

What command is need to set the time on a Windows server when it boots?

I am running a Windows server on a VM and the time isn't accurate after it reboots. Is there a command to set the time on a Windows 2008 via NTP when it boots? It needs to run at boot time not at ...
2
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3answers
470 views

Should I timesync against PDC Emulator or NTP timesource? (PDC not in hub)

I know the best practice would be to have the PDC Emulator to sync against an external NTP time source, and have all other domain controllers sync against the PDC Emulator. However, my network layout ...
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2answers
92 views

Timekeeping between various Windows computers on network (but not all)

I have a situation where I have the following setup: ============Primary Network=============== = = Bridging Server = ...
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3answers
2k views

Linux Centos 6.2 “hangs” until date is synchronized

I'm having a problem that i cannot understand why or how to solve it. I have a Centos 6.2 server, that's my secondary DNS (bind 8) and DHCP (ISC's dhcp server). I need to maintain an accurate date ...
5
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1answer
749 views

How well will ntpd work when the latency is highly variable?

I have an application where we are using some non-standard networking equipment (cannot be changed) that goes into a dormant state between traffic bursts. The network latency is very high for the ...
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1answer
140 views

Use ntpd to log time adjustments rather than set system clock

Is it possible to use ntpd to log all time resets and adjustments rather than set system clock?
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1answer
690 views

ntpdate cannot receive data

I have a problem where running ntpdate on my server doesn't return any data therefore I get the following error: [root@server etc]# ntpdate -d -u -v time.nist.gov 12 Apr 01:10:09 ntpdate[32072]: ...
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3answers
10k views

How to configure ntpd to sync time more frequently?

I need to set ntpd to sync time as often as possible, how to do that? UPD I need to make ntpd adjust system clock more frequently, not poll servers. It's necessary because system clock of my virtual ...
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1answer
713 views

Time sync fails on Hyper-V VM, but succeeds when I log in as a domain user

We have a Windows Server 2003 SP2 VM running on Hyper-V (Server 2008 R2 host). The VM has Hyper-V time synchronization enabled. I noticed that the time on the VM was fast by around 25 minutes. I saw ...
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1answer
1k views

Dual DC Time Service

I believe I'm having an issue with my Domain Controllers and Time Server. On my back up DC, I keep seeing a warning stating "The time service has stopped advertising as a time source because the ...
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1answer
228 views

Multiple NTP Server Instances on One Server (Linux)

Is it possible to run multiple NTP server instances on the same system? We're using CentOS for our NTP system and want to synchronize specific time depending on what interface the client comes in on. ...
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2answers
8k views

NTP configuration not recognized?

I'm trying to configure NTP on my machine but it seems that the parameters I set are not being read by the system. Below is my /etc/ntp.conf file. (I applied the most basic configuration to eliminate ...
2
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1answer
128 views

Do CDMA based time servers passively read timing information from the cell network?

GPS based time servers are receive only, that is, they passively read the timing information from the GPS network. Do CDMA based time servers work the same way? In other words, do CDMA based time ...
4
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2answers
3k views

Best practices for NTP updating in VirtualBox virtual machines without guest additions?

I have a couple of VMs that cannot have guest additions installed, and I pause and resume them with days between. I normally forget to nudge NTP when I start up the VM. Is there a good way to tell ...
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2answers
1k views

Identify NTP clients using my server

I have an HPUX NTP Server. It is the server for a dumb client device that has NTP built-in. I can tell the client the server IP and interval but cannot get any logging out. How do I know if NTP ...
2
votes
1answer
6k views

NTP not syncing, only syncs on service restart

My ubuntu 11.10 server has been sitting there quite happily for the last 3 - 4 months, then suddenly the time started going out of sync by one hour. I'm not sure why, nothing has changed re the ...
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2answers
1k views

State of the art auto time sync? [closed]

Placing ntpdate into cron seems to be no longer a good idea. What is an easy state-of-the-art automatic environmental friendly ;-) sleek way of keeping a (debian) server's time clock up to date?
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3answers
1k views

sync time on linux using ntp and persist it

on linux to sync time with ntp you say ntpdate pool.ntp.org however after reboots, the time gets reset to some odd value again. is there a way to persist the changes? how do I set the computer ...
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2answers
2k views

Change Domain Controller time +5 minutes

I have medium-sized Windows network of 60 workstations and 10 servers (2 of which are Domain Controllers). One DC holds the FSMO roles including the PDC Emulator. This the DC with PDC does not sync ...
1
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2answers
263 views

Windows 2008 - Time Sync

What is the threshold in Windows 2008 when the local clock differs from an NTP source and it will not synchronize? For example, if the local time is off > 2 days, will NTP still sync? Is there a ...
1
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1answer
2k views

Windows 2008 R2 64 bit multihomed. NTP time synching issue

I have a DMZ machine that i wish to sync to a time source ().pool.ntp.org. Perimeter Firewall is setup to allow relevant ports through. Obviously local FW on the server is on and configured to allow ...
3
votes
2answers
867 views

Increasing time difference between Windows Server 2003 and time.nist.gov even after explicitly syncing time

I have synced the time of my server to time.nist.gov. This server communicates with a client’s server which is also synced with time.nist.gov. After noting that we seemed to be out of sync with the ...
2
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1answer
773 views

Windows NTP client changes timezone to Pacific automatically

I have a Windows 2008 server machine and I am trying to use this public IP 128.252.19.1 to synchronize the time, however, I would like my system to have Eastern timezone. When I enter the ...
0
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1answer
883 views

Meinberg ntp for Windows - force more frequent updates?

I have a Windows VM that has time drift problems, and left to its own devices will drift by minutes per day. I know there are issues with time on VMs, but I was hoping using the Meinberg NTP service ...
2
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1answer
920 views

How to return to Default settings of NTP/Time server on domain with GP

This is an Edit - according to the comments, I may have not been understood/ Facts: I have a Windows 2003 Domain PDC Emulator is enabled and working correctly on my DC I have a GPO that is NOT ...
3
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1answer
3k views

How can I disable NTP in pfsense?

I am running my pfSense gateway in a ESXi server. right now the server gets its time from the NTP server specified in the general settings section of the WebGUI. I want to disable this so pfSense ...
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1answer
146 views

Current time is off on a Windows 2003 Server DC

I have a single server that is also a domain controller in a cabinet, there are no other servers attached to its domain. I've reset the time in the BIOS (from what I recall) and in Windows to the ...
1
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1answer
341 views

NTP on main server, and alternative on virtual (LXC)

I am setting up a server with several VPS. I am using LXC. I am thinking it would be better to have only the main server equipped with ntp and have the virtual boxes just get the time from the main ...
1
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1answer
589 views

Windows XP NTP client authentication

I'm trying to configure a Windows XP NTP client to authenticate to a local NTP server on our closed network. How can I make this happen? One article I've found for configuring the client to talk to a ...
2
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1answer
257 views

Is it possible to monitor NTP through SNMP in Linux

Is it possible to monitor the NTP drift value ( I mean measuring the time difference between the NTP server and the server that I am trying to monitor) using SNMP.
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3answers
3k views

How to configure an authoritative time server in Windows Server

I have a performance lab running behind a firewall, so none of the machines in the lab has internet access. All machines in the lab are part of a domain with the domain controller also present inside ...
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0answers
64 views

NTP problems in one AD OU?

We have one domain with OU's for each geographic site. We have five physical sites; one in Asia, two in Europe, and two in the U.S. (not sure if this might have any bearing on the situation). One ...
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2answers
20k views

WS2008 NTP - Using time.windows.com,0x9 - Time always skewed forwards

I have a domain controller configured to use time.windows.com (with 0x09 flags set). I've noticed that frequently the systems' clock is fast - it varies from 10 minutes to even 45 minutes. I always ...
0
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2answers
279 views

Virtualizing NTP server [duplicate]

Possible Duplicate: What are the limits of running NTP servers in virtual machines? I was wondering if virtualizing NTP is okay. I have a VMware ESXi 5.0 box, and I want to virtualize my ...