The Network Time Protocol, is used to synchronize system clocks to precision time servers on the internet or locally connected devices such as a GPS.

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2
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2answers
44 views

Use default gateway as ntp server

I have a lot of servers running debian and they all must synchronize clock to NTP server running on their respective default gateway. Since there is many servers on many different network segments, I ...
0
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1answer
57 views

Troubleshooting GSS-API error on one client authenticating to Kerberos

When authenticating to kadmin with one client of many, it fails with kadmin: GSS-API (or Kerberos) error while initializing kadmin interface. The Kerberos host is specified with its subnet ...
0
votes
1answer
76 views

How to set NTP tinker step (which unit)? and how to query?

One of the workaround for old CentOS/CentOS kernel (6.1-6.3) which may "Systems hang due to leap-second livelock." (quoting redhat), is to set tinker step in /etc/ntp.conf. Bug the documentation is ...
0
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0answers
46 views

Do I need to stop NTP service for client or only the server for leap second bug in linux

I have a server with suse 11 sp1 which are connected to NTP server that is also of same version. How can prevent leap second bug from effecting the servers? Can stoping the NTP service prevent effects ...
0
votes
1answer
37 views

ntpdate timeout ambiguity

Does the ntpdate option -t set the timeout in whole seconds or fractions? The man page isn't entire clear. It says -t timeout Specify the maximum time waiting for a server response as the ...
1
vote
1answer
23 views

dhcp3-server and strange DNS/NTP servers

I have problem with dhcp3-server 3.1.1-6+lenny4. My dhcp-server sends "strange" IPs for DNS and NTP servers in DHCP ACK despite configuration which doesn't have those IPs. In ACK packet we can see the ...
5
votes
5answers
1k views

How to get system time with microsecond Resolution

I want to know current system time with microsecond Resolution. date +%s returns Time in seconds since epoch(1-1-1970). How can I get time in microseconds Resolution. How much delay is in querying ...
4
votes
2answers
71 views

Force time to stay put

The time on my Linux machine will not stay put. I need to test an issue with our server that only occurs on Saturdays. CentOS 6.5 64-bit I have NTPD off. (service ntpd stop and chkconfig ntpd off) ...
3
votes
0answers
46 views

Linux Mint system clock is days ahead after an overnight laptop suspend

I'm a long-time Ubuntu user, who recently started trying out Linux Mint on a laptop. This is not a dual-boot setup, Mint is the only OS on the machine. When I suspend the laptop (i.e. close the ...
1
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0answers
54 views

How can I consistently tell OpenSUSE to refresh the clock / current time?

I use OpenSUSE in a VM and sometimes want to save the machine and get back to work later. I haven't had much success with hibernate or suspend, so I simply save the state of the machine and resume ...
0
votes
1answer
24 views

What ntpq command or configuration setting would show output from a statum 1 server?

How can I tell ntpq to output servers other than stratum 2? Currently ntpq -p prints this. But what I need is at least one stratum 1 server in the output. I've read here and here. I've also tried ...
0
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0answers
55 views

NTP setup on a Java application Linux server

In a farm of time sensitive Java application Linux servers, how should one configure NTP in the ntp.conf file? Would it be okay to point the server to four stratum 3 NTP servers (switches) that are ...
3
votes
1answer
158 views

How to run ntp commands as non-root?

NTP commands such as ntpd and ntpdate are privileged and belongs to the root group. What is the best way to run these commands as non-root ? Linux capabilities, ownership, any method ? I have openSUSE ...
2
votes
1answer
402 views

Automatically update hwclock at boot

We're having a small issue with our Beagle Bone Blacks. Since they do not come with a RTC battery, when they lose power, the hardware clock gets messed up. I need a simple and clean way of syncing the ...
4
votes
1answer
211 views

RTC time synchronization not working (CONFIG_RTC_SYSTOHC)

I have the option CONFIG_RTC_SYSTOHC enabled in my kernel: Device Drivers ---> [*] Real Time Clock ---> [*] Set the RTC time based on NTP synchronization The help says: ...
0
votes
1answer
75 views

script does not execute

I have rPi B+ running ArchLinux with kernel Linux comp001 3.18.6-2-ARCH #1 PREEMPT Sun Feb 8 09:43:43 MST 2015 armv6l GNU/Linux with Real Time Clock hardware RTC Pi. However, I would like to check if ...
1
vote
0answers
61 views

What causes ntpq refid CRYP when authentication is successful?

I have five servers that I'm configuring for production use based on a configuration we've recently tested. The servers are RHEL6 with NTP version 4.2.4p8@1.1612-o. Right now, though, I'm trying to ...
0
votes
1answer
27 views

Do I need nomodify set on NTP servers which are not publicly accessible?

I am configuring five new RHEL6 NTP servers. Each uses a list of five USNO servers as their source with at least one unique server one each one. Each of the five servers also peers to the others. None ...
1
vote
0answers
55 views

NTP authentication failing with opcode 108

I'm trying to get NTP authentication working on a cluster of test servers and a couple clients. I've followed the instructions at ntp.org. To be honest, though, I'm not sure they are entirely clear ...
4
votes
2answers
1k views

ntp.conf peer vs server

I'm setting up an NTP server (one of what will be five in a cluster). My config file: restrict default kod nomodify notrap driftfile /var/lib/ntp/drift server tick.usno.navy.mil server ntp.colby.edu ...
4
votes
2answers
287 views

How long will NTP take to adjust the clock if it doesn't immediately set it?

I'm using SNTP to sync my Debian based system. SNTP has two ways to set the clock: -s, --settod Set (step) the time with settimeofday(). -j, --adjtime Set (slew) the time with adjtime(). The ...
0
votes
0answers
149 views

NTP compilation failed - without ssl

I am trying to cross compile NTP ver 4.2.8 without SSL support. I gave --without-crypto while configuring, but still it was throwing following error: ../libntp/libntp.a(ntp_crypto_rnd.o): In function ...
-2
votes
1answer
98 views

How much RAM and CPU for a NTP server? [closed]

As a side project, I am thinking about adding a NTP server to pool.ntp.org. I would like to use CentOS basic, but how much RAM and CPU should I assign to a machine that will only be running ntpd (plus ...
4
votes
2answers
410 views

Use local NTP service

I'm trying to get a system with no outside internet access (A) to get the time from another system on the LAN that does (B). In A's ntp.conf (the whole thing is at bottom), I've added: server ...
7
votes
1answer
124 views

NTP and NTPD Nanokernel

I had a couple of questions about the NTP Nanokernel as explained here: http://www.eecis.udel.edu/~mills/database/brief/nano/nano.pdf The big question is how does this Nanokernel manage to deliver an ...
0
votes
2answers
109 views

How to update NTP without shutting down the NTP daemon?

I would like to have a one-liner for updating the date via NTP getting the NTP-servers from the /etc/ntp.conf file. Especially because a manual command does not always work, because of firewall rules, ...
2
votes
2answers
558 views

How do you deal with unreliable NTP peers?

I ran lynis 1.5.6 and got the following log message. Performing test ID TIME-3120 (Check unreliable NTP peers) Test: Checking unreliable ntp peers Result: Found one or more unreliable peers (marked ...
1
vote
2answers
126 views

ntpd installed to local directory, now have two versions

I got the latest version of ntpd because the binary releases have vulnerabilities. Unfortunately, after I built it and ran make install, it was installed to /usr/local/sbin, but the system is running ...
8
votes
1answer
8k views

ntpdate -d seems successful, but ntpdate returns no server suitable

I've got a system that is not running ntpd on which I'm attempting to update the clock using ntpdate. The system is an appliance that appears to be CentOS 6 based. When I run ntpdate 0.pool.ntp.org, ...
2
votes
2answers
107 views

Time requires to synch. UNIX server with NTP server; after manually chaging te UNIX server's time

I have a GPS server with NTP output. I want to synchronize the clock on the UNIX server using the NTP output of the GPS. After changing the UNIX server time manually, UNIX server takes a long time to ...
2
votes
1answer
253 views

NTPd Not Syncing on RaspberryPi

Since my hardware (RasberryPi) does not have a hardware-clock, each bootup warps us back to the 1970's, so I use NTP. The gateway on the network I am on provides an NTP-Server service. my ...
5
votes
1answer
276 views

Arch Linux RPI: How accurate is the time on the RPi in Linux?

Currently I'm working on a application on my RPi which will be monitoring a set of GPIOs in real-time where the exact time when the GPIO turns HIGH is crucial for my application. And I need to know ...
0
votes
1answer
10k views

How to keep Debian internal clock synchronized (with NTP servers)?

I have a home server which runs an up to date Debian 7.5 (wheezy) installation. I just discovered that the server has its internal clock set to ± 3 minutes in the future. I knew that I can use NTP ...
4
votes
1answer
544 views

Properly configuring symmetric active NTP?

I'm trying to configure two NTP servers to be peers to each other but I have no idea how to tell if it is working or not or whether my NTP configuration is even correct. I've put a simplified view of ...
3
votes
1answer
87 views

NTP with networks isolated

I have a computer (CentOS) with 2 network cards. I want to use one network card (A) to retrieve time from NTP server (internet). This would then set [this] local computer's time. I then want to ...
0
votes
1answer
2k views

IPTables allow NTP Time Server

I am new to IPTables. I have an existing config that seems to work well. I am not sure I know how to add NTP to the rule Chain RH-Firewall-1-INPUT correctly. My goal is to add an additional rule to ...
1
vote
1answer
260 views

How to know my server's time offset? [duplicate]

I have a few guest machines on VMware. Up until now I was keeping my time sync with ntpd inside guests. Now our VMware admins decided to setup VM hosts to keep time, so VMs don't have to. I disabled ...
2
votes
1answer
511 views

Why is ntpd listening on most of 192.168.1.X/192.168.2.X

I'm using the ntp package in debian squeeze and the ntpd process is listening on hundreds of rfc1918 addresses that are not configured on the server. Check this out: Mar 26 10:07:24 server ...
2
votes
2answers
694 views

Strip specific option from a response in dhclient

I aim to prohibit dhclient from updating my NTP config with servers received via DHCP, as it is the default on Debian/Ubuntu. However, my DHCP server ignores the list of requested options (from the ...
6
votes
3answers
8k views

timed out, nothing received

I tried all and googled a lot! But I can't make work NTP on my server. This post is last hope! I have installed ntp on debian server with this configuration (/etc/ntp.conf): driftfile ...
4
votes
1answer
3k views

Why am I getting apparmor error messages in the syslog about NTP and LDAP?

On my newly installed Ubuntu 12.04 machine, with ntp and slapd installed, the following messages appear in /var/log/syslog at regular intervals: Feb 23 18:54:07 my-host kernel: [ 24.610703] ...
6
votes
1answer
1k views

Why doesn't NTP increase polling interval when using a GPS/PPS receiver and internet servers?

I have a Debian system that is used as an NTP server. It queries several servers on the internet and also has a GPS receiver with PPS output for precision timekeeping. If I don't use the GPS ...
6
votes
1answer
6k views

Arch ntpd/ntpdate not synchronizng clock

My raspi running Arch isnt updating time with NTPD. Im running [root@fatpi ~]# cat /proc/version Linux version 3.10.28-1-ARCH (nobody@root-armv6-copy) (gcc version 4.8.2 20131219 (prerelease) ...
2
votes
2answers
2k views

Setup ntp client with embedded device

I need to run an NTP client on a very limited embedded device. ntpd is available but I do not see anything like rc.conf, or ntp.conf, or xntp.conf? Can someone advise on how to setup NTP? I ran ...
1
vote
0answers
923 views

NTP Problems - sntp: too many bad or lost packets

I need some help from you guys regarding NTP on Suse. I have a server, whose IP is 192.168.100.52, which is based on Suse Linux and here is my NTP conf file: server 192.168.100.11 iburst restrict ...
1
vote
1answer
845 views

last reboot/uptime/… strange behaviour

I know this has been more or less asked before but I still don't have any answer. I started to investigate why on my system (it is a remote machine) who -b and uptime gave different results (~3 days ...
4
votes
1answer
514 views

Does ntpd default allow query requests through?

I am confused as to what is the default access policy of an ntp server. According to the ntp_acc man page, access can only be denied if specifically blacklisted. Clients can be denied service ...
2
votes
1answer
752 views

NTP is synced properly but still doesn't update the time?

I wanted to test if ntp was working on my machine, so I set the time back 5 minutes and restarted ntp $ sudo service ntp stop $ sudo date -s "9:40 AM" # This time was 5 minutes ago $ sudo service ntp ...
13
votes
3answers
5k views

What is the recommended way to synchronize time using NTP?

This question has come up a number of times in a localized way, this question is meant to provide the preferred/best method for synchronizing a system's clock using NTP. The solution should handle ...
0
votes
1answer
356 views

How can I make a Puppet module that fixes time? [duplicate]

I have written a Puppet module that corrects the time via NTP, but this only works on server with a small NTP offset. There are sometimes server with a time offset higher than 10 minutes for various ...