Customer Support: NTP Client Software List

NTP Client Software

The Network Time Protocol (NTP) is a client/server application. Each workstation, router, or server must be equipped with NTP client software to synchronize its clock to the network time server. In most cases the client software is already resident in the operating system of each device.

Two steps are all that is required to establish your synchronized network time source:

1. Connect the time server to your network.

2. Install and/or configure the client software on each workstation that will interface to the server. Setting up an NTP or SNTP client is relatively simple once you have successfully communicated with your time server over the network.

It is not necessary to purchase expensive client software. In most cases, the client software is already resident in the operating system of the workstation, server or router. In other cases, it is available as freeware, shareware or inexpensive applications. The following list is by no means exhaustive, as there are numerous client software applications available. It is just a small sample of what is available and is NOT a list of recommendations.

For a basic overview of how NTP works, please read our "Introduction to NTP" white paper.

Windows | Unix/Linux | iSeries | Cisco

Windows 2000, XP, 2003

Official NTP Distribution for Windows - The links at ntp.org point to free, compiled versions of the NTP distribution for Windows platforms. If you are serious enough about reliable timekeeping to purchase a Stratum 1 timeserver, we think you should be using "real NTP" client software. It offers robustness and configuration capabilities that can prevent catastrophic synchronization failures. Highly-recommended.

W32Time - Microsoft Windows includes a built-in time service called Windows Time or W32Time. You will need to configure this Time Service by editing some registry entries. Click here for information.

Tardis 2000 - Tardis is a shareware utility for Windows that makes sure your PC's clock tells the right time. It can find out what the right time is in various ways including accessing Internet-based Atomic Clocks, using networked timeservers, GPS, Radio Clocks, and by listening for time broadcasts over a LAN. Tardis 2000 is rated 5 Cows on Tucows and is used on the International Space Station.

YATS32 - This application lets you reliably and automatically set your system clock to any of a number of time services available over your corporate intranet. It supports multiple servers and time service protocols such as SNTP and TIME.

Domain Time II - Domain Time II is more robust than the native W32Time Server (see above) and is designed to replace it. W32Time was designed to keep the computer clocks within a domain roughly synchronized but was never intended to be an enterprise time solution. It is good enough for Kerberos on Windows 2000, but does not attempt to address timing needs beyond that.

Unix/Linux

Several manufacturers include the NTP daemon as part of their OS release. If your OS does not, we suggest you use the original NTP code itself which is freely available from http://www.ntp.org. Documentation is included in the download that provides information on how to install the software on various Unix platforms.

Sun includes the official NTP reference distribution in many versions of their operating systems. For the most recent information, search http://docs.sun.com for "NTP".

Chrony - Chrony is a pair of programs which are used to maintain the accuracy of the system clock on a computer. The two programs are called chronyd (a daemon) and chronyc (a user interface to chronyd for monitoring/configuring). For Linux/Solaris/BSD.

iSeries and AS/400

Client Server Development makes a product called Atomic Time Manager 400 which synchronizes iSeries and AS/400 hardware and software clocks to an NTP server.

Cisco Routers and Firewalls

Cisco provides online documentation for the IOS system.
IOS 12: Instructions for configuring NTP/SNTP are in the IOS Release 12.0 Configuration Fundamentals Guide.
IOS 10 and 11: Look under "Managing The System" of the Configuration Guide to find NTP configuration information.