HP-UX Internet Services Administrator's Guide (August 2003)

Configuring NTP
Getting Started with NTP
Chapter 458
NTP Equipment
The following equipments are required to effectively use the NTP
programs:
• Internet or your own radio receiver, such as GPS (Global Positioning
System), as a time source.
• An ordinary network, such as an Ethernet, in your building.
• Familiarity with configuring and setting up NTP.
Starting NTP Configuration
For a basic NTP configuration, you must complete the following steps:
1. Choose a source of time.
2. Determine how frequently the system clock must synchronize with
the source of time.
3. Select backup time server.
4. Configure the primary NTP server.
The following sections cover these steps in detail.
Choosing the Source of Time
Government organizations define, regulate and distribute time for
synchronization purpose. These organizations constantly coordinate and
synchronize their clocks with other organizations within nanoseconds of
each other. The first step in usingNTP is selecting the best source oftime
for your organization.
You must be careful while selecting the source of time. If the type of
applications and processes the users run are sensitive to time, you must
select the source of time that provides a stable time, and is not affected
by network delays. Do not select the NTP service depending on price.
Also, select a source of time that you can reach fast. The closer the source
of time, the better. Choose a source that is physically close and one that
takes few network hops to reach the destination. For more information
on physical and network distance, see “Configuring Mulltiple Time
Servers” on page 221.