The Network Time Protocol is a way to syncronize
the clock of your Linux computer with another computer somewhere else on
the network. The software to implement this protocol is in the XNTP3
rpm, which contains the xntpd deamon, as well as the xntpdate command.
How To Install NTP
% mount /dev/cdrom
% cd /mnt/cdrom/RedHat/RPMS
% rpm -ivh xntp*.rpm
How To Configure NTP
Configure your /etc/ntp.conf file
You simply specify the servers
that you will use, and the location of the driftfile. The driftfile
is used to calculate the drift of the clock on the system that the xntp
daemon is running on. Here is an example of the /etc/ntp.conf file:
sever time.foo.com driftfile
/etc/ntp.drift peer friend.foo.com
The server line specifies that this machine will get its time from
time.foo.com. The peer line specifies that this machine can both get
its time from friend.foo.com, as well s proide its on time for
synchronization. The peer line is not recommended.
About NTP Stratium N servers
A stratum 1 server has access to an
external time source such as a radio clock. A stratum 2 server gets
its time from a struatum 1 server. A stratum 3 server gets its time
from a stratum 2 server. This continues all the way down to stratum
15 servers. There are no stratum 16 servers or beyond.
The xntpdate and rdate commands
The xntpdate command works to
update your clock once, rather than keeping your clock in sync.
There is another command that does this called rdate, but it is not as
accurate as the using xntpd. Running rdate with the -s option will set the
system clock to the time recieved from the time server.
