Using the NTP Service of Technische Hochschule Augsburg

The Aztecs, like the even more cultered Mayans, had several separate, overlapping calendrical systems. This picture is said to symbolize one of them. In the middle it shows two gods representing life and death. The animal symbols on the left and right margins stand for 20 day or month names. Unlike our day counts and month names, the ones in this religious calendar cycle simultaneously. A 13-day count and 20 names result in 260 unique dates, forming the divine year. Refer to the book 'Calendrical calculations' mentioned in the 'Time' page.

Uses

Usage means correcting the clocks of one or several workstations by referring to NTP hosts in your local network or in the Internet. The kind of usage of this and other NTP services depends on your needs and some restrictions.

MS Windows users in an enterprise or campus network don't need to know anything about time synchronization, provided their system administrator has set up an authoritative time server.

Under Unix and Linux, the common NTP deamon is as well used with an authoritative time server. NTP is delivered ready-to-run with modern Unixes and Linuxes and just has to be set up by an admin.

So the following is targetet at system administrators of client computers running MS Windows, Mac OS, or Unix/Linux. But server administrators are addressed as well.

Internal clients (in our campus network) should refer to one of our distribution (NTP stratum 3) servers, see the NTP subnet page. Be sure to declare our NTP hosts servers, not peers in your NTP setup.

External clients (not in our campus network) should refer to a geographically close NTP Pool Time Server or even have their system administrator set up an own NTP subnet.

We would be glad to let our stratum-2 servers peer with yours, what would give you a clock accuracy better than ±5 milliseconds. You'd need two or three stratum-2 hosts to get accurate time into your campus network, like we do. Look around at this site for some basic information.

Unix/Linux

On a Unix or Linux machine you should use the original ntpd software. It is shipped along with most modern Unix and Linux variants, though sometimes in an out-dated version. But it's easy to update it with the built-in package installer. You may even get the latest version from the 'Home of the Network Time Protocol', but that's not really needed.

As an internal admin, edit the /etc/ntp.conf file to contain one of the following lines:
server time.hs-augsburg.de
for normal clock accuracy or
server time.rz.hs-augsburg.de
for even better accuracy.
As an external admin, replace our server's address by whatever your server's is. That's the bare minimum, you better have a real (full) configuration file.

You may get some suggestions from the NTP cookbook of the University of Michigan.

Internal clients may also use the campus NTP broadcast service. To get the necessary authentication keys you have to contact the operator of this service.

MS Windows

In a MS Windows network, there is an integrated time client-server hierarchy based upon SNTP. Only one authoritative server in an enterprise network should refer to an external SNTP server. Server administrators should go to the Microsoft Support Server and search the Searcheable Knowledge Base for the keyword SNTP to get more information.

As an internal admin, let MS Windows workstations refer to
time.hs-augsburg.de.
As an external admin, replace our server's address by whatever your server's is.

Other

Apple Macintosh machines that run OS X have the original ntpd daemon running since the OS is essentially a kind of Unix.

CISCO routers may be able to serve as NTP peers. Please consult the manual.

Hint

Remember to configure your operating system for the correct time zone and daylight saving time regulations. Such settings are not part of NTP.