The NTP package contains a client and server to keep the time synchronized between various computers over a network. This package is the official reference implementation of the NTP protocol.
Download (HTTP): http://www.eecis.udel.edu/~ntp/ntp_spool/ntp4/ntp-4.1.2.tar.gz
Download (FTP): ftp://ftp.udel.edu/pub/ntp/ntp4/ntp-4.1.2.tar.gz
Download size: 2.2 MB
Estimated Disk space required: 13 MB
Estimated build time:
Install NTP by running the following commands:
./configure --prefix=/usr && make && make install |
The following configuration file defines various NTP servers to use with the primary server designated with the prefer tag. It also creates a drift file where ntpd stores the frequency offset. Since the documentation included with the package is sparse, visit the NTP website at http://www.ntp.org/ for more information.
server time-a.nist.gov prefer server time-b.nist.gov server tick.usno.navy.mil driftfile /var/cache/ntp.drift |
There are two options. Option one is to use run ntpd continuously and allow it to synchronize the time in a gradual manner. The other option is to run ntpd periodically (using cron) and update the time each time ntpd is scheduled.
If you choose Option one, then create the bootscript /etc/rc.d/init.d/ntp and put the start and stop symlinks:
#!/bin/bash # Begin $rc_base/init.d/ntp source /etc/sysconfig/rc source $rc_functions case "$1" in start) echo "Starting ntpd..." loadproc ntpd ;; stop) echo "Stopping ntpd..." killproc ntpd ;; restart) $0 stop sleep 1 $0 start ;; status) statusproc ntpd ;; *) echo "Usage: $0 {start|stop|restart|status}" exit 1 ;; esac # End $rc_base/init.d/ntp |
If you prefer to start ntpd periodically, add the following command to the root's crontab:
ntpd -q |
ntpd: NTP daemon that runs in the background and keeps the date/time synchronized based on response from configured NTP servers. It also functions as a NTP server.
ntpdate: NTP Client program that sets the date/time based on the response from an NTP Server. This command is deprecated.
ntp-genkeys: This program generates cryptographic data files used by the NTPv4 authentication and identification schemes. a ARPANET file transfer client.
ntpdc and ntpq: Programs to query and set ntpd configuration.
ntptrace: Trace a chain of NTP servers back to the primary source.