[CentOS] NTP

Mon Apr 2 15:32:52 UTC 2007
Ken Godee <ken at perfect-image.com>

>>> 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
>>
> 
> I do wish it would prefer the time server offered by DHCP:-( I'd rather 
> sync one computer over the Internet, and the rest off my local network.
> 

I'm not a NTP expert but...........

Keeping time in sync within fractions of a second is reasonable.
Google and test a few severs, NTP has a host of tools that will tell
you which servers are responding the best, adjust what servers you use 
accordingly.

NTP runs as a daemon and will automatically keep track of time drift and 
adjust itself as to how often it needs to poll the servers. If your 
system keeps good time it may only poll once an hour.

One server can be set to sync via the internet (firewall/gateway server)
and the rest of the local network syncs to this box, you only need one
server to sync over the internet and then the local network (linux & 
windows system) sync to that server.