Installing and Administering Internet Services

296 Chapter7
Configuring the Network Time Protocol (NTP)
Getting Started with NTP
server ntp-cup.external.hp.com
server bigben.cac.washington.edu
server sirius.ctr.columbia.edu
Back-up Time Servers
After you have found a well-configured time server that is an acceptable
distance away, you must select two additional servers. These servers will
serve as back up time servers. The closest and fastest one will be your
primary time server. The others will do the job if the primary server
becomes unavailable. The process of establishing back-up servers is
know as employing redundancy. It is a safeguard for your network users.
It ensures that their time sensitive applications will always be able to
run because there will always be a reliable source of time to synchronize
to.
NOTE You should select at least three other servers for redundancy.
Configuring Your Primary NTP Server
Step 5. Install the latest version of NTP.
Step 6. Select a source of time: radio receivers, public time server, local NTP
machine.
Step 7. Add the name of the server to the file /etc/ntp.conf:
server my_server.my_domain.my_org.com
Note that my_server.my_domain.my_org.com is the complete name of
your server.
Step 8. Specify the time source and add its information to the configuration file.
• For Radio Receivers:
1. Uncomment the following “fudge” line found at the end of the file
/etc/ntp.confserver 127.127.26.1.
#fudge 127.127.26.1 time1 -0.955
2. Make a link to the device file that corresponds to the serial port
you are connecting to the GPS unit by typing the following: