EndRun Tempus LX GPS, User Manual

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T e m p u s L X G P S U s e r M a n u a l 19
"Smarter Timing Solutions"
Chapter
Three
Setting Up NTP Clients on Unix-like Platforms
To configure your Unix-like computer to use your Tempus LX, you must have successfully completed
the Basic Installation procedures in Chapter 2. This manual is not a ‘How-To’ on installing and
using NTP; basic approaches to NTP client configuration for operation with the Tempus LX will be
described. It is expected that you are, or have access to, a capable Unix/Linux system administra-
tor and know more than a little about installing distributions from source code. Installation must be
performed by a user with root priviledges on the system. If you have never used NTP, then you should
spend some time reading the on-line documents, especially the Distribution Notes, FAQ and Configu-
ration subject matter, which are available at: http://www.ntp.org
Although all the information is available at the above site, the following are excellent tutorials on set-
ting up NTP and are easier to understand:
http://www.sun.com/solutions/blueprints/0701/NTP.pdf
http://www.sun.com/solutions/blueprints/0801/NTPpt2.pdf
http://www.sun.com/solutions/blueprints/0901/NTPpt3.pdf
If you have a news service, many problems may be solved by the helpful people who participate in
the Internet news group devoted to NTP at comp.protocols.time.ntp.
Three methods of using the Tempus LX with NTP clients on Unix-like platforms will be described:
Basic:
This is the simplest, and will operate without MD5 authentication.
NTP beginners should
always perform this setup first .
MD5:
This method is trickier only because MD5 keys must be set up and distributed accurately to
the NTP clients in a secure way. The Tempus LX is factory configured to authenticate
its replies to NTP MD5 clients using its default set of keys.
Broadcast/Multicast: This method simplifies configuration of the clients on large networks since
specific server addresses need not be configured in each client’s
/etc/ntp.conf
file. It can be config-
ured either with or without MD5 authentication. However, it is highly recommended that authentica-
tion be configured when using broadcast/multicast mode due to the relative ease with which a fake
NTP server can take over the clock setting of the broadcast/multicast clients on the network.