C# SNTP Client
Though not obvious, time synchronization is sometimes important. The best example is the Kerberos authentication protocol, which requires the resources to be synchronized within minutes or even seconds, but there are other situations as well. The Network Time Protocol (NTP) and its simplified form (SNTP) are widely used to synchronize network resources, due to their simplicity and effectiveness. There are many programs available that synchronize your PC's clock with that of a time server. Dimension 4 is my favorite.
In case you need time synchronization embedded into your software, here is the C# alternative. It's simple, fast and integrates seamlessly with the .NET platform. There is a Java implementation of a NTP client by Michel Van den Bergh, but I don't have the URL anymore. If Michel (or anyone else that knows it) reads this and emails me, then I'll update the article.
There are several time severs on the Internet and the list below contains those operated by NIST. If you need more, you can probably find a few more using any standard Internet search engine.
| Name | IP Address | Location |
| time-a.nist.gov | 129.6.15.28 | NIST, Gaithersburg, Maryland |
| time-b.nist.gov | 129.6.15.29 | NIST, Gaithersburg, Maryland |
| time-a.timefreq.bldrdoc.gov | 132.163.4.101 | NIST, Boulder, Colorado |
| time-b.timefreq.bldrdoc.gov | 132.163.4.102 | NIST, Boulder, Colorado |
| time-c.timefreq.bldrdoc.gov | 132.163.4.103 | NIST, Boulder, Colorado |
| utcnist.colorado.edu | 128.138.140.44 | University of Colorado, Boulder |
| time.nist.gov | 192.43.244.18 | NCAR, Boulder, Colorado |
| time-nw.nist.gov | 131.107.1.10 | Microsoft, Redmond, Washington |
| nist1.datum.com | 209.0.72.7 | Datum, San Jose, California |
| nist1.dc.certifiedtime.com | 216.200.93.8 | Abovnet, Virginia |
| nist1.nyc.certifiedtime.com | 208.184.49.9 | Abovnet, New York City |
| nist1.sjc.certifiedtime.com | 208.185.146.41 | Abovnet, San Jose, California |
The server time.nist.gov yields the following results:
The NTPClient class is simply to use. Follow the example below:
NTPClient client;
try
{
client = new NTPClient("time.nist.gov");
client.Connect();
}
catch(Exception e)
{
Console.WriteLine("ERROR: {0}", e.Message);
return;
}
Console.Write(client.ToString());
Downloads
Download source - 4 KbDownload demo project - 7 Kb

Comments
utc time
Posted by arvind on 03/15/2013 08:26amhello, thanks for the effort. is there a method for GMT time.
ReplyLatest version...
Posted by scamurra on 09/22/2010 04:35pmHello, How can I get a version that will compile in .NET 2 or 3.5? Thanks
ReplyTiming Accuracy Issue
Posted by ppledge on 03/25/2008 09:15amNice Article, excellent class. I am concerned however that you use the DateTime for time stamping incoming messages. Although the DateTime class has room and drags digits out to the nanosecond range, it is only updated by windows every 10-15 milliseconds or so (easy to check out, get the time in a for loop and output it to a file or display, you will see that it doesn't change). In order to get real millisecond accuracy, you need someting like a performance timer synchronized to the windows clock. Other then that, it is excellent. p
ReplyCan't compile demo project...
Posted by Legacy on 06/11/2003 12:00amOriginally posted by: xaero
I Can't compile your demo project.
ReplyJava Version
Posted by Legacy on 03/09/2003 12:00amOriginally posted by: Damian Penney
Found the Van Den Bergh Java implementation at http://alpha.luc.ac.be/cgi-bin/Research/Algebra/java.cgi
ReplyPlease add project in VS6.0, too
Posted by Legacy on 11/02/2001 12:00amOriginally posted by: MartinBi
Hi,
I would like to use you class in Visual Studio 6.0,
but you add only VS7.0 projects.
Please correct this problem.
Thank you
ReplyMartin, Poland