Friday, 9 September 2011

SBS 2003 Error: DNS Event ID 4521: The DNS server encountered error 9002 attempting to load zone . from Active Directory

This has been mentioned before but bears being mentioned again since the SBS 2003 we are just getting ready to migrated to SBS 2011 on a 2 node Hyper-V Server 2008 R2 failover cluster is throwing these errors:


Event Type:    Warning
Event Source:    DNS
Event Category:    None
Event ID:    4521
Date:        9/9/2011
Time:        2:30:39 PM
User:        N/A
Computer:    -SBS01
The DNS server encountered error 9002 attempting to load zone . from Active Directory. The DNS server will attempt to load this zone again on the next timeout cycle. This can be caused by high Active Directory load and may be a transient condition.

For more information, see Help and Support Center at

The fix is quite simple:

  1. Open a command prompt.
  2. dnscmd /config /BootMethod [Enter]
  3. net stop dns && net start dns [Enter]
  4. Close the command prompt.

Now that we have run the above commands we are no longer seeing the errors in the DNS Event Log:


Since this particular domain is one of our own creations we are pretty confident that everything is okay health wise. We will still walk through all of the source server health steps found in our Migration Guide here:

Our original blog post is here:

Philip Elder
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book

*Our original iMac was stolen (previous blog post). We now have a new MacBook Pro courtesy of Vlad Mazek, owner of OWN.

Windows Live Writer


Phil Wisch said...

I looked up /bootmethod on technet.

I'm guessing leaving /bootmethod blank defaults to 0, no source. So you set your dns not to use a source? Or am I mistaken on the default?

Philip Elder SBS MVP said...


Yeah, something is up since the errors went away following the instructions but came back after a reboot.

Not going to delve too much into it though since this box will be DCPromod out (SBS 03 to 11 migration) sometime in the next 24 hours.