Questions tagged [ntp]

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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Does Amazon manage time synchronization on ECS/Fargate containers?

I'm trying to use NTP to synchronize local time in ECS containers using the ntpdate command, but it gives me this error: ntpdate[770]: Can't adjust the time of day: Operation not permitted ...
Aramis Rodríguez Blanco's user avatar
3 votes
2 answers
19k views

NTP time sync failures on Debian

This is on HypriotOS (Debian GNU/Linux 10) running on RaPi. $ timedatectl show-timesync Failed to parse bus message: Connection timed out Then do this with sudo: $ sudo timedatectl timesync-status ...
Marcel Stör's user avatar
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1k views

NTPD deleting interface eno3

Our server is loosing connection one time every day and we must reboot it manualy to get the netword coming back! The only line we can see and is certainly responsible of that is this one : ntpd[1009]...
Recif's user avatar
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What happens when ntp stops sync with remote ntp server and LOCAL (127.0.0.1) is also not defined in the ntp.conf

I wish to understand the scenario in which we have defined only remote servers in the /etc/ntp.conf file and we have not set the LOCAL ntp server (127.0.0.1) options. What happens in case of a ...
Mustafa Alam's user avatar
2 votes
3 answers
3k views

Which ntp command replaces ntpdate -q?

On older systems, where ntpdate is still available, I'm able to query an NTP-Server without setting ntpdate -q pool.ntp.org and got e.g.: server 213.239.239.164, stratum 2, offset -0.001191, ...
Achim's user avatar
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Can a CentOS 8 chrony client synchronize with a CentOS 7 ntp server?

Can a CentOS 8 chrony client synchronize with a CentOS 7 ntp server? By ntp server, I mean it was configured through yum installing the ntp package and not the chrony package.
Levi Uzodike's user avatar
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1 answer
9k views

How to change time source from a LOCAL CMOS CLOCK to a Cisco router configured as a NTP master

I have a test network that I'm using for my CCNA. I am using my Cisco 2811 router as an NTP master. I think I have it configured correctly. Is there a Cisco command to see what NTP time source I am ...
Acenyc's user avatar
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Changing ntpversion in ntpq packets

So im using ntpq Ver 4.2.8p13, and it seems the default NTP Version that it claims in packages is version 2, as shown by: root@kali:~# ntpq -c ntpversion NTP version being claimed is 2 However, when ...
Sam's user avatar
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3 answers
9k views

How to synchronize clocks on servers with no internet access?

I would like to synchronize the clocks on 10 Ubuntu 16.04 servers all with no internet access. Based on my internet searches, ntp does not seem to be designed for this. What is the easiest way to do ...
user551744's user avatar
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Ceph Clock Skew

I want to know where I can configure the limit of skew time for my ceph monitors. Also,how does CEPH throw this clock skew error? Specifically from which file and where can I find the file so that I ...
 Zeeshan Haris's user avatar
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all my ntpd servers marked falsetick, why?

I have a set of four ntpd servers that sync time from the same stratum 1 server. But on some clients they all are marked falsetick, why? remote refid st t when poll reach delay ...
poison1456's user avatar
1 vote
1 answer
1k views

Unable to ntp query host that I have connection to

So I have an ethernet point to point connection from my PC to a device running NTP on UDP port 123. This is what nmap shows: root@kali:~# nmap -sU mydevice PORT STATE SERVICE 123/udp open|...
Sam's user avatar
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chronyd on debian could not open IPv6 NTP socket

$ sudo journalctl -fu chrony -- Logs begin at Thu 2019-11-14 03:51:16 UTC. -- Nov 22 01:46:40 miranda-ntp-server-01 chronyd[5984]: Selected source 169.254.169.123 Nov 22 02:29:29 miranda-ntp-server-01 ...
Mzq's user avatar
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Domain Controller Acting As NTP but using NT5DS

We are currently using a PDC setup for our domain controllers to be our NTP server but in the REGEDIT it is showing type NT5DC instead of NTP. The issue that I am having is that our non domain ...
Mbonifacini's user avatar
1 vote
1 answer
321 views

NTP time synchronization [closed]

I have two Linux computers connected to each other via Ethernet crossover cable. No Internet Connection! How can I make the first computer always sync to the time of the second computer? I tried ...
dani's user avatar
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Cannot change "w32tm /query /source" from "Local CMOS Clock" on PDC Domain Controller

I am trying to reconfigure the time settings for a single DC W2K8R2 domain. The DC is not a VM. I followed the instructions on this page to the letter..... https://gooroo.io/GoorooTHINK/Article/17139/...
Justin Grimes's user avatar
2 votes
0 answers
4k views

linux + understanding Chrony logs and conclusions from logs

we are using chrony service in order to sync linux clients to NTP server in our cluster since we get diff time between machines we enable the chrony logs to understand the reasons that machines in ...
shalom's user avatar
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0 answers
23 views

Centos NTP time skew alerts [duplicate]

I have a couple of NTP Stratum 2 servers, and these are in sync with a Stratum 1 GPS appliance, and also peered between them selves. I would be interested in creating a job, which will create an alert ...
Mus's user avatar
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Windows 7 NTP is not working to synchronise [closed]

i have a Windows 7 SP1 PC, and i am trying to synchronising to an internal NTP Server, but is not working. IT is failed. The PC is a part of a domain and the internal server also is in the same domain....
Dimitrios's user avatar
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858 views

Chrony on RHEL7.2 can sync to windows ntp server, But Chrony on RHEL7.4 can't sync it [closed]

according to redhat link: https://access.redhat.com/solutions/3425701 we can see that - Chrony on RHEL7.2 can sync to windows ntp server, But Chrony on RHEL7.4 can't sync it. in my case we have ...
shalom's user avatar
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1 answer
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how configure chrony in orphan mode

I have two centos servers without internet i tried to enable orphan mode so they synch with each other but still time is not synchronized between them. Find below my settings and output of commands /...
ImranRazaKhan's user avatar
1 vote
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152 views

NTP reach property equivalent for timedatectl command

The ntpq -p command returns information which includes the reach and when properties as shown in the example: remote refid st t when poll reach delay offset jitter ==========...
Tony.H's user avatar
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selinux and ntp , dose selinux heve negative impact on ntp

we have redhat linux servers in spite chrony.conf is set correctly with the right ntp servers we see very strange behavior that time is still sync to ntp server but change from some reason we ...
shalom's user avatar
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2 votes
1 answer
338 views

XenServer 8.0 running a NTP client in guest PVHVM VM

I would like to run a NTP client in a Xen Linux VM under XenServer (XCP-NG 8.0 to be precise). The Linux VM, Debian Stretch 9.9 (uname -a: Linux debian 4.9.0-9 amd64 #1 SMP Debian 4.9.168-1+deb9u4 (...
zyash's user avatar
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3 votes
1 answer
5k views

Setting up an NTP server from LAN - KoD packet has inconsistent xmt/org/rec timestamps. Ignoring

I'm setting up a NTP server on my Ubuntu machine and I want my Raspberry Pi's and (eventually) Window's machines to sync from it. I thought things would be pretty straight forward, however I'm ...
Ackis's user avatar
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0 answers
783 views

Local GPS clock is marked as falseticker by ntpd — why?

I have a Linux NTP server with a ublox M8Q GPS module connected via GPIO (UART @ 9600bps and PPS). What I observe is that the local GPS source — SHM(0) — gets marked as falseticker and I'd like to ...
NPE's user avatar
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Why is the /var/log/chrony folder empty?

We are using chrony in order to sync our Red Hat (7.2) servers with NTP servers. In order to do so, we've configured the logdir /var/log/chrony in chrony.conf and restarted the chrony via systemctl ...
shalom's user avatar
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2 votes
1 answer
727 views

Configuring isc-dhcpd server for DHCPv6 with multiple NTP addresses

I'm trying to configure a DHCPv6 server to provide more than one NTP address (option 56) using the isc-dhcpd server. Is there a currently supported way of doing this? My first attempt was defining a ...
vbeljan's user avatar
  • 21
1 vote
2 answers
770 views

NTP NIC binding

I'm wondering whether it's possible to setup NTP on a Windows Server running 2012 R2. The catch is that I only want one of the two NICs on the server to be used for NTP. Here's a little more ...
Luke Welden's user avatar
0 votes
1 answer
737 views

Configure Windows NTP service for Linux clients

I have 100 Linux clients and a Windows Server 2016 in a closed network environment. I would like to have the Ubuntu clients time sync with the Windows Server's date-time. I have done this on internet-...
Robert Daniels's user avatar
3 votes
1 answer
5k views

What does x indicate beside NTP IP in the output of ntpq -p

Recently, I see an "x" appears beside NTP server IP in the "ntpq -p" output. Although my server seems to be connected to the peer NTP server, it's supposed to show an "*" instead of "x" prior to the ...
aschkant's user avatar
0 votes
0 answers
521 views

Machines experience time offset despite chronyd service running

we have 3 machines in the cluster ( redhat 7.2 ) linux_machine1 linux_machine2 linux_machine3 the machines time are like this Sun Sep 1 13:54:20 UTC 2019 - linux_machine1 Sun Sep 1 13:34:15 UTC ...
shalom's user avatar
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0 votes
1 answer
706 views

centos 7 NTP configuration

I am trying to configure ntp.conf with a stratum 1 server and also a peer VM on the same network. Config file is attached below. The problem is server with the IP address 10.6.11.171 does not seem to ...
Mus's user avatar
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0 votes
0 answers
169 views

querying data from NTP in ubuntu using socket

I have configured ntp to use gpsd as reference server on my machine. I am querying data from ntp directly, using udp socket. For ip address I use localhost and port_number = 123. Packet structure I ...
debonair's user avatar
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0 votes
1 answer
295 views

Dell S-switches (S3124.S3048, S4048) and ntpq

We are using several Dell switches (S3124, S3048 and S4048, running OS9) in a network and want to use them as ntp-sources. That works fine, but none of these responds to NTP queries (ntpq -pn). What ...
Marko's user avatar
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0 votes
0 answers
116 views

ntp + ntp loose synchronize each time in 5:00 morning

we have a very strange behavior we have 12 Linux redhat machines - redhat 7.x two of these VM servers are loosing the time synchronize each day at 5:00 in the morning after we restart the chronyd , ...
shalom's user avatar
  • 501
0 votes
1 answer
169 views

Set up a NTP server which can be queried globally

I want to set up a server (hosted on aws/or a running system in some part of the world) as an NTP server that can be queried globally. Currently, I have modified the ntp.conf file on the node to be ...
Swapnil Pandey's user avatar
0 votes
2 answers
17k views

Domain-joined computer won't switch time source to domain from "Local CMOS Clock"

My situation is almost identical to the one cited in this post: How to change time source from "Local CMOS Clock" to "DC" I have a domain-joined computer that is showing "Local ...
Jason O's user avatar
  • 159
2 votes
1 answer
3k views

There's no ntpd in centos 7, how to sync time automatically and manually with chrony?

Seems there's no ntpd in centos7, how can I sync time in centos7? I found out that chrony should be used in centos7, what is manual way to update time using chrony? I assume chronyd is something ...
gacopu's user avatar
  • 191
6 votes
1 answer
646 views

Using GPS as only source for NTP daemon

I have questions regarding the use of a GPS receiver as an external clock source for realization of a time server with NTP daemon (client version 3), on a local network with no connection to external ...
waldemar's user avatar
0 votes
2 answers
3k views

CentOS 7 - how does timedatectl sync time and date without NTP?

I am creating automated tests for an rsync-like utility and I need to be able to set the clock back 24 hours for one of the tests. However, when I use timedatectl to set the time and date they ...
Not a machine's user avatar
2 votes
1 answer
1k views

NTP Servers Not Syncing At Boot

Backstory: I have a couple of internal startum 1 NTP clocks with GPS receivers, and 2 public NTP servers that are virtualized on top of VMware ESXi which take time from the S1 clocks and distribute it....
Stuggi's user avatar
  • 3,576
3 votes
1 answer
1k views

NTP Server - Display DNS name as reference ID

Backstory, I operate a couple of public stratum 2 NTP servers that are part of the NTP pool. These then sync to internal stratum 1 NTP clocks. The issue I have is that clients using the public NTP ...
Stuggi's user avatar
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0 votes
1 answer
2k views

Traceroute to check NTP - possible?

In the past I mostly used tcptraceroute to check http and ssh. Now I need to check if my host can reach the NTP server. Is this possible at all? I have two machines. At application level I see: ...
guettli's user avatar
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4 votes
2 answers
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How should nftables rules using hostnames be rewritten to deal with multiple addresses?

I have this nftables rule: ip daddr { "0.nixos.pool.ntp.org", "1.nixos.pool.ntp.org", "2.nixos.pool.ntp.org", "3.nixos.pool.ntp.org" } udp dport ntp accept comment "Allow NTP traffic for system time" ...
Jean-Paul Calderone's user avatar
3 votes
1 answer
769 views

are ntp.org pools and time.windows.com safe from gps 2019 week rollover?

Can anyone point to any public doc stating that pools from ntp.org and time.windows.com are safe from next thrusday gps week rollover ? I am looking to something similar to this Red Hat KB https://...
golemwashere's user avatar
2 votes
1 answer
3k views

NTP time sync issues Windows Server 2016

So, I'm running into some issues trying to configure NTP sync on my DC. This is a Virtual Machine running on Hyper-V. I disabled time sync for this VM. I forwarded 123/udp both on the windows firewall ...
Mrpopo666's user avatar
0 votes
1 answer
2k views

Query on NTP current time source

I have a query regarding ntpd options and the ntpq command. I have set up a local NTP Server in Ubuntu 14.04 PC and NTP Client is a custom development platform based on Renesas RZ/G1H. I have ...
user514875's user avatar
0 votes
4 answers
1k views

ntp offset with stratum 1 , when using stratum 2

I was searching for a solution but didn't find clear answer. In my company, all our servers are syncing time with one of our private ntp servers (which are stratum 3 if I'm correct). These stratum 3 ...
vercetty92's user avatar
2 votes
3 answers
4k views

securing/hardening ntp client on Linux servers - config file

I have a clean install of Debian with the NTP client. I was given settings to secure secure my NTP client configuration. I know how to add them to the /etc/ntp.conf file but I am not if settings need ...
IMTheNachoMan's user avatar

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