How to install ntp

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If you liked this article, then do subscribe to email alerts for Linux tutorials. If you have any questions or doubts? Related Posts. All done as per step, but no NTP sync. Got something to say? Join the discussion. Cancel reply Have a question or suggestion? It allows a client to authenticate a server for trusted information exchange. Authentication is based on a number of agreed keys, or passwords, that are available to both client and server. When a message is transferred from server to client, it is appended with an encrypted version of one of the keys.

The keys are stored in the file in the following format:. The first field is a unique key number indicator. The final field is the actual key itself. Any number of keys can be specified. As well as the agreed keys, you can also specify which of the keys are trusted. Therefore, a subset of the keys can be specified for use at any particular time.

For instance keys 2, 8 and 15 above can be used for use for a specific period. A number of utilities are provided that can be used to debug a NTP installation. This is an application that will query an NTP server and can be used to find out if it is working within expected parameters. The response indicates the time references that the server is currently utilizing and which is its currently preferred reference.

Therefore you must ensure that the port is open in any network firewall. You will also need to leave the port open in any host firewall application. Also, ensure no other NTP client application is in use, such as timesyncd or any third party software.

Add reference clock peers to the configuration file. Add drift file location to the configuration file. Add optional statistics directory to the configuration file. Enable and start the NTP service. Check operation and synchronization status. Introduction If you need to keep the system time on your Linux computer accurate, NTP is the solution. Add Reference Clock Peers NTP relies on reference clock servers, or peers, in order to synchronize the local system clock.

Specifying Statistics File Directory You can use the statsdir command in the configuration file to specify a directory where statistics files will be stored.

Whether the PPS Hack is to be used, or not, could be configured via an environment variable. A kernel mode driver can but not necessarily will provide time stamps with less jitter than any user mode application, but loopback-ppsapi-provider. In case you wonder about the name: This provider loops back into ntpd to tap into information already there. However, specifying a DLL name in an evironment variable was found to be a potential security risk see Bug , so with ntpd 4.

When the instsrv. To set up the key manually, run the Windows regedit. See also the notes below. When it comes to controlling the PPS hack, there is some dependency between those two settings. It's better to avoid this area where dragons are roaming unless you feel really adventurous. If the DLL name is specified as file name only , without a path, then the DLL is assumed in the same directory as ntpd.

If the Meinberg installer is used then the loopback-ppsapi-provider. Please note there is a bug in ntpd 4. See Bug for details and a workaround. NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service DDoS attacks.