Welcome to vCenter Configuration Manager : Using Operating System Provisioning : Getting Started with OS Provisioning : Synchronize Clocks on Installed Linux Operating Systems
- Configure Domain Controller to synchronize time with external NTP server (uk.ntp.pool.org) UDP port 123 must be open on firewall to allow NTP traffic in and out from this DC. From DC command prompt type telnet portquiz.net 123 to test if the port 123 traffic can go out.
- To Synchronize Clock with an Internet Time Server in Internet Time Settings 1 Open the Control Panel (icons view), and click/tap on the Date and Time icon. 2 Click/tap on the Internet Time tab, and click/tap on the Change settings button. (see screenshot below).
- About time synchronization. There are various ways to determine the precise time. For ordinary people, the most convenient and easy way is to use time synchronization servers (NTP server). Most operating systems installed on computers and mobile devices have a built-in feature for working with such NTP-servers.
- Network Time Protocol (NTP) Network Time Protocol (NTP) is the default time synchronization protocol used by the Windows Time Service (WTS) in Windows servers and workstations. NTP is implemented via UDP over port 123 and can operate in broadcast and multicast modes, or by direct queries.
When Linux machines are provisioned with an operating system, the Network Time Protocol (NTP) service is not running. After moving the newly provisioned Linux machines to a network with access to the NTP server, you must synchronize the time on the machines to network time.
Prerequisites
Synchronize server time with NTP for the hobbyists among us. Go to start and search for Command Prompt. Click Command Prompt with right mouse click and choose Run as Administrator. We cannot update the server time without running Command Prompt (CMD) as Administrator.
- Configure the Linux machines on a network with access to the NTP server.
- Identify the NTP servers used in your environment.
Procedure
- On the Linux machine, log in as root.
- Run the ntpdate -u <ntpserver> command to update the machine clock.For example, ntpdate -u ntp-time.for.mydomain.
- Open the /etc/ntp.conf file and add the NTP servers used in your environment.You can add multiple NTP servers similar to these examples.server ntp-time.for.mydomainserver otherntp.server.orgserver ntp.research.gov
- Run the service ntpd start command to start the NTP service and implement you configuration changes.
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Knowing the precise time is very important in the modern world, where everything can change literally in a matter of minutes. Sometimes just a few seconds can be granted in order to solve the problem. Fortunately, the capability to know the precise time anywhere in the world is not a difficult task. It is enough to have at hand any device with the access to the Internet. Let’s consider how to determine the precise time on smartphones and tablets operating under Android.
About time synchronization
There are various ways to determine the precise time. For ordinary people, the most convenient and easy way is to use time synchronization servers (NTP server). Most operating systems installed on computers and mobile devices have a built-in feature for working with such NTP-servers. The algorithm for synchronizing the device's internal time with time on a remote server is quite simple:
- The user device sends off a request to the synchronization server using a special network protocol — NTP (Network Time Protocol).
- In response to the request, the server generates an NTP packet with the required data and sends it back to the user device.
- The built-in synchronization feature processes the packet and adjusts the internal time of the device using the data from the NTP packet.
- High synchronization precision (up to one hundredth of a second, i.e. 10 milliseconds) is achieved due to the fact that the time setting function takes into account the delay between sending off the request and receiving the NTP-packet from server.
The NTP server itself determines the precise time according to a really (physically) existing time standard. This is a whole complex of equipment which task is to count time. There are several time standards in the world located in technologically advanced countries, including Russia. The atomic clock is available at the All-Russian Scientific Research Institute of Physicotechnical and Radiotechnical Measurements (VNIIFTRI).
Time synchronization with TimeServer on Android
Sync Time With Ntp Server Ubuntu
Android operating systems also have a built-in feature of time synchronization via the net. However, users can not configure it. The system checks the time with the NTP server, which, in fact, is unknown to the owner of the Android device. It also remains a secret how exactly the basic time synchronization feature works under Android.
For the time synchronization on smartphones and tablets running under Android there is only one way — the use of special applications. However, here there are some nuances. Android OS prohibits third-party applications to change the date and time settings, which is done for security reasons. In order to let the time synchronization applications work on a full scale, the user needs root-rights. Without the root-rights such programs can not change the system settings in automatic mode; however they can still determine the precise time. In this case, the user will occasionally have to manually set the time on his Android device.
Let's learn how it is done using an example of time synchronization application ClockSync with NTP-server timeserver.ru.
ClockSync with root-rights
Step 1
Open Google Play on your smartphone or tablet and download the ClockSync application.
Step 2
Run the application and go to its settings. To access the menu, click the button in the upper right corner of the application.
Step 3
Step 4
Type in the address in the 'NTP server' field — timeserver.ru and click 'OK'.
Step 5
Click the return button on your smartphone to return to the previous page and go to the the main menu again. If the device has the root access, then select 'Update' and allow the root access for the application if such a message appears on the screen.
Step 6
In the 'Offset' section, the system time offset will be displayed in comparison with time on the NTP server.
Step 7
Step 8
If the synchronization is successful, a respective message will be displayed at the bottom of the screen.
Step 9
To activate the automatic time setting feature, go back to 'Settings', and check the 'Enable automatic synchronization' box. You can set the synchronization period in the 'Interval' section.
ClockSync without root-rights
Step 1
Follow steps 1 to 6 according to the instructions above. After the server has been set, go to the main page of the application, open the settings menu and select 'Synchronize' in it. The program will not be able to automatically change the system time, so the smartphone will open the time and date settings section, and a reverse timer will appear at the bottom of the screen.
Step 2
Windows Ntp Time Server Address
First, switch the 'Use Internet time' slider to the off position. Then open the 'Time' section.
Step 3
Set the hour (in this case — 16 hours). Then move the 'minute hand' to the position indicated in the 'Time' section (in this case — 40 minutes).
Synchronize Time With Ntp Server Download
Step 4
Synchronize Time With Ntp Server Settings
As soon as the timer reaches '00', press the 'OK' button. The current precise time will be saved on your Android device.
This procedure can be performed once a month or more often. The error in synchronization in manual mode is 1 second.
This procedure can be performed once a month or more often. The error in synchronization in manual mode is 1 second.