[CentOS] NTP

[Peter Gross]

Mike wrote:
> Greets!
> 
> Ok.  I'm looking at a client that needs to keep their server time close 
> as reasonably possible (within a minute) of the actual time of day.  
> I've installed the RPM for NTP and I'm looking for tips on what the 
> simplest setup should be, ie:
> What server(s) should I be using for sync?
> Should I just run it from a cron every 20 minutes or so?

CentOS 4.4 standard NTP install /etc/ntp.conf is set to use the 
following NTP servers:

server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org

These are sorta special in that they are backed by many different 
servers and DNS queries expand them for you (do a "dig 0.pool.ntp.org a" 
to see what I mean). Each time you do a DNS query to one of those 
addresses you will get a different set of servers returned.

So to simplify what I'm saying you just need to:

# yum install ntp (if not already installed)
# chkconfig ntpd on
# service ntpd start