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Chapter 9, Administration and Automation
#71 Update Your Clock via the Internet
HACK
This hack explores a little tool called the Network Time Protocol (NTP) that
can solve your inaccurate-clock problems. The NTP software synchronizes
your computer’s clock with a central server on the Internet with impressive
accuracy, and if you set this synchronization to occur when your system
boots (or at regular intervals), your clock will never be inaccurate again.
Getting NTP
The NTP software is available for download from http://www.ntp.org, but it
is probably best to use your distributions package-management program to
obtain the software.
With the software installed, you need to find a server with which to synchro-
nize your clock. Many ISPs provide NTP services to their subscribers; con-
tact your ISP to see if it has a server to synchronize with. If your ISP does not
provide a server, a number of public NTP servers are available for different
regions of the world. The easiest way to find these servers is to search on
Google for your location/country and the words public NTP server. For
quick synchronizations which lead to a more accurate clock, choose a server
as physically close to your geographic location as possible. Also, because
you are an end user, you should not synchronize to a stratum 1 server. These
servers are reserved for use only when you are setting up your own NTP
server that will service ...