To set up the SCs and domains as NTP clients, edit the ntp.conf file. The xntpd(1M) daemon reads the ntp.conf file at startup time. The configuration must contain a minimum of three time servers (with independent time sources), as recommended by the NTP protocol designers.
Using a text editor, edit the ntp.conf file by inserting the following lines for the main SC, the spare SC, and the bootable domains. Be sure to add the prefer argument to the host that is preferred for synchronization.
# /etc/inet/ntp.conf server NTP_Server1 prefer server NTP_Server2 server NTP_Server3
The drift file should also be added to record the frequency offset of the local clock oscillator. The drift file is read at startup to set the initial frequency offset. Add the following line to the ntp.conf file:
Statistics and file generation should also be used. Be sure to indicate the directory path where statistics files should be created. In the following example, peerstats are generated to record peer statistics, and loopstats are generated to record loop filter statistics. Finally, clockstats are generated to record clock driver statistics.
To set up statistics and file generation, add the following lines to the ntp.conf file:
statsdir /var/ntp/ntpstats filegen peerstats file peerstats type day enable filegen loopstats file loopstats type day enable filegen clockstats file clockstats type day enable
You should set up a cron(1M) job to remove the existing statistics files on a regular basis.
The following is a full example of an ntp.conf file:
# /etc/inet/ntp.conf server clock.via.net prefer server navobs1.usnogps.navy.mil server ntp.ucsd.edu driftfile /var/ntp/ntp.drift statsdir /var/ntp/ntpstats filegen peerstats file peerstats type day enable filegen loopstats file loopstats type day enable filegen clockstats file clockstats type day enable
After you have edited the ntp.conf file, you must stop and restart the NTP daemon, as in the following example:
sc:# /etc/init.d/xntpd stop sc:# /etc/init.d/xntpd start
NTP is an insecure protocol. If you are running a secure environment, you should take additional steps to implement the appropriate level of security. Refer to the Sun BluePrints™ articles cited in the "References" section.