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I have found many different webpages all saying to put different strings in for the value HKLM\System\CurrentControlSet\Services\NTDS\Parameters\DSA Heuristics. From what I can tell it appears to be a bit-mask, is there a MSDN page where I can see what different values really mean instead of just taking the word of people who say "Just put this in".

I have attempted to use Google to find out about it but I have had no luck in my searches.

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No, not authoritative.

It disables "strict search hash checking". This is most commonly used to workaround issues resulting from some query parameters being changed in-flight during multi-page ldap queries.

Here is an example:

"Could not connect to a directory server" error message when you click the “last page” button in the search results in Exchange Server 2007 OWA

Note that there is a dsHeuristics attribute in Active Directory, and that is very well documented in the Active Directory Technical Specification.

More information from here:

"When the original request is executed, the system builds a string, called a “search argument signature”, and hashes it. The resultant hash is then stored with the restart argument. When the second page is retrieved, the restart argument is queried and the “search argument signature” is recomputed and hashed. If the new hash does not match the stored hash, the system fails the request."

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The issue is it does a lot more than just that. It also Disables the disabling of Write-Cache and it can Disable Circular Logging (you may need to put in the : by hand in the url). – Scott Chamberlain Jun 5 '12 at 16:23

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