Solved

Time Skew Vs. Synchronization

Posted on 2011-03-17
8
1,121 Views
Last Modified: 2012-06-21
In a Windows 2003 AD domain

Is there a time skew range between which a computer will/will not synchronize its clock?

I know Kerberos Authentication, by default, will not occur if the skew is >5min.

(I.E. If workstation time differs from server time by ____ minutes time synchronization fails?)

0
Comment
Question by:alexianit
  • 2
  • 2
  • 2
  • +1
8 Comments
 
LVL 5

Expert Comment

by:BatchV
ID: 35156542
Hi Have a look at this link, it explains in detail your question

http://support.microsoft.com/?kbid=224799
0
 
LVL 27

Expert Comment

by:michko
ID: 35156718
the referenced article above refers to windows 2000 specifically.  some of the information is still applicable to a server 2003 domain, but not all.

From my understanding, there is not a time skew range between which a computer will not synchronize its clock.  

there is a time skew range of 5 minutes on 2003 domain where things actions differ.

if the time skew is less than 5 minutes ahead, then the computer will slow its clock until it matches the synchronizing server time.

If the time skew is more than 5 minutes ahead, the computer will immediately match to the synchronizing server time.

If the time skew is behind the server time, then the computer will immediately match to the synchronizing server time.

Note that in windows 2000 the actions are the same, but the time skew is 3 minutes instead of 5.

technical reference for Windows Server 2003 and later if you're interested:
http://technet.microsoft.com/en-us/library/cc773061%28WS.10%29.aspx#w2k3tr_times_intro

0
 
LVL 25

Accepted Solution

by:
Dr. Klahn earned 125 total points
ID: 35156869
Yes, there are time difference adjustement limits for some systems.  Microsoft discusses this in KB884776.

"The Windows 32 time service supports two registry entries, the MaxPosPhaseCorrection and the MaxNegPhaseCorrection."

For Windows XP and Server 2003, "The default value of these two registry entries is 0xFFFFFFFF. This default value means 'Accept any time change.'"  In my experience this is not correct; XP systems out of the box do have limits.

For standalone systems, "The MaxPosPhaseCorrection and MaxNegPhaseCorrection registry entries have a default value of 54,000 (15 hours). As a security best practice, we recommend that you reduce this default value. We also recommend that you set the value to 3600 (1 hour) or an even smaller value, depending on time source, on network condition, on poll interval, and on security requirements."
0
PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

 
LVL 25

Expert Comment

by:Dr. Klahn
ID: 35156890
As a side issue, the MaxPosPhaseCorrection and MaxNegPhaseCorrection limits do not affect changes to and from Daylight Saving Time.
0
 
LVL 5

Expert Comment

by:BatchV
ID: 35157125
If workstation can logon to domain it will always correct time automatically however if the time difference is too great than the workstation will fail to logon to domain and you will get an error message warning you about this. I believe this is where the default value of 15hours comes in.
0
 

Author Comment

by:alexianit
ID: 35393740
Objecting to accept answers.
0
 

Author Closing Comment

by:alexianit
ID: 35393748
Good answer!
0

Featured Post

Enterprise Mobility and BYOD For Dummies

Like “For Dummies” books, you can read this in whatever order you choose and learn about mobility and BYOD; and how to put a competitive mobile infrastructure in place. Developed for SMBs and large enterprises alike, you will find helpful use cases, planning, and implementation.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Today, still in the boom of Apple, PC's and products, nearly 50% of the computer users use Windows as graphical operating systems. If you are among those users who love windows, but are grappling to keep the system's hard drive optimized, then you s…
Possible fixes for Windows 7 and Windows Server 2008 updating problem. Solutions mentioned are from Microsoft themselves. I started a case with them from our Microsoft Silver Partner option to open a case and get direct support from Microsoft. If s…
This Micro Tutorial will give you a introduction in two parts how to utilize Windows Live Movie Maker to its maximum editing capability. This will be demonstrated using Windows Live Movie Maker on Windows 7 operating system.
The viewer will learn how to successfully download and install the SARDU utility on Windows 7, without downloading adware.

809 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question