I agree with KevinT. Using Group Policy one can change the tolerances with
the time drift. There are some 1U rack-mounted NTP servers that use
satellite + atomic (radium? Cesium? Can't remember) that you can point all
of your systems to. Last I checked I think I saw some for around 5k.
-----Original Message-----
From: ***@securityfocus.com [mailto:***@securityfocus.com] On
Behalf Of Kevin Tunison
Sent: Monday, October 20, 2008 4:58 PM
To: Chris Teodorski
Cc: security-***@securityfocus.com
Subject: Re: Windows time and PCI compliance
On Mon, Oct 20, 2008 at 4:12 PM, Chris Teodorski
Post by Chris TeodorskiHello all,
The PCI/DSS section 10.4 has pretty specific requirements for clock
synchronization. Our experience with the Windows Time service has
been less than stellar. Can anyone recommend a good reliable windows
NTP client?
I imagine several others of you out there are fighting with PCI/DSS compliance.
Thanks,
Chris
By the windows time service being less than stellar, surely you are
referring to the default links within the ntp client and not the
software itself, as it conforms to RFC 1769. Those links are easily
modified (and any good administrator will do such), especially in a
domain environment.
If it is the changing of a system time you are worried about, get GPO
involved (and any good administrator will do such) at both the domain
and workstation level where appropriate. On the domain one can set
time-changing restrictions at the following Group Policy location:
Local Computer, Computer Config, Windows Settings, Security Settings,
Local Policies, User rights assignment, change system time.
Stick with Stratum 1 ntp servers. The U.S. navy is a good choice, but
there are others.
Read this: http://support.ntp.org/bin/view/Servers/RulesOfEngagement
where you will also find a list of open, registration, and restricted
NTP servers in the 1st stratum.
Regards,
KevinT