Installing and Administering Internet Services

286 Chapter7
Configuring the Network Time Protocol (NTP)
Getting Started with NTP
To set up the local clock impersonator, add the following line to the
/etc/ntp.conf file:
server 127.127.1.1 minpoll 3 maxpoll 4
Radio Receiver
The radio receiver is the most accurate. When you use it, you have no
worries about network delays, congestion, or outages. It is, however, the
most expensive time distribution mechanism. Some of the popular radio
receiver method are: GPS (Global Positioning System), WWV (terrestrial
North America), and DCF77 (terrestrial Europe).
If you select the radio receiver, remember that you must consider the
cabling options.Antenna cables can be very expensive and RS232 cabling
has a limited range.
The official HP supported GPS receivers are HP58503 driver#26 and
Trimble Palisade driver#29. The only supported WWVB receiver is
Spectracom Netclock/2 driver#4. DCF77 (AM and FM) signals radiate
from Frankfurt Germany. None of the DCF77 receivers are officially
supported by HP.
To Set up a HP58503A GPS Receiver
1. Install and connect the receiver and antenna to a serial port on the
HP-UX machine.
2. Add the following files to the end of your /etc/ntp.conf file:
server 127.127.26.1 minpoll 3 maxpoll 4
# fudge 127.127.26.1 time1 -0.955 #s700
# fudge 127.127.26.1 time1 -0.930 #s800
3. Uncomment the correct “# fudge” line for your architecture.
Uncomment the #fudge ... #s800 line for servers or uncomment
#fudge ... #s700 for workstations.
To Set up a Trimble Palisade GPS Receiver
1. Install and connect the receiver and antenna to a serial port on the
HP-UX machine.
2. Add the following files to the end of your /etc/ntp.conf file:
server 127.127.29.1 #poll period is fixed at 32 seconds
# no fudge required
# fudge 127.127.26.1 time1 -0.930 #s800