Re: Clock syncronization

["Patrick \"Duane\" Dunston" <duane@xxxxxxxxxxx>]

Hey,

Run: timeconfig

to get your server time to the right zone.

I'd recommend you have have one local server synch with an external server 
and have the other servers sync with that local server.  

On the server that syncs externally you can use "time" via inetd or 
xinetd to synch with the remote server.  Enable the "time" server on the 
linux box via xinetd.  Edit the file /etc/xinet.d/time.  Change the line:

disable = yes

to

disable = no

reload xinetd. /etc/rc.d/init.d/xinetd reload

be sure time is running:

lsof -i -n |grep time

Then use tcpwrappers to restrict only the hosts that need to sync with it.  
Be sure to allow access only from the clients who need it.  Whether you 
use time, ntp, or xntp you should only allow clients that need it.

In hosts.allow

time : 10.1.1.2,10.1.1.3,10.1.1.4

Run rdate on the server that wil synch externally and sync with one of the 
servers that you are allowed to synch with.  Here's a list:

http://www.eecis.udel.edu/~mills/ntp/clock2.html

The top of the list contain servers you can use in brazil.

On each server you can then run rdate through cront to sync with your 
local time server however often you need.  

rdate -s <local server ip address> ; hwclock --systohc

hwclock will synchronize your hardware clock to to proper time.

There is an rdate for windows, winrdate: 
http://www.contactor.se/~dast/stuff/

at the bottom of the above link's page.

you can then use the MS scheduler to sync periodically from the windows 
server.

Hope this helps.

On Mon, 11 Nov 2002, Bruno Gimenes Pereti wrote:

> Hello,
> 
> I think this question is related with security. I need to sync the clock of
> 4 linux box and 1 windows 2000 server.
> 
> First of all, I need to know how to configure the correct time to my
> zonetime (Brazil East GMT -03:00). I´m using RedHat.
> 
> Secondly, do you use NTP do sync the clock of your machines? What do I need
> to do to use it?
> 
> TIA,
> Bruno.
> 
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-- 
duane

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