Setting lDAPAdminLimits via Powershell
I was having a conversation with a friend the other day and he brought up a question about updating the AD property lDAPAdminLimits.
The Problem
The property is stored as an array of string values (at least as far as Powershell is concerned.) The initial reaction was do try something like this $queryPolicies.lDAPAdminLimits.MaxNotificationPerConn = 30, but this assumed that MaxNotficationPerConn was a property of lDAPAdminLimits and not the actual value (or at least part of the value.)
The Solution
Use the ADSI method PutEX to modify the value. PutEx uses ADS_PROPERTY_OPERATION_ENUM to make selective changes to an existing property. In the script below, we add the new value using the Update operation and then use the Delete operation to remove the old value.
Some Examples of Use
D:\Scripts\Set-ldapAdminPolicy.ps1 MaxNotificationPerConn 45
D:\Scripts\Set-ldapAdminPolicy.ps1 MaxQueryDuration 360
D:\Scripts\Set-ldapAdminPolicy.ps1 MaxPageSize 500
D:\Scripts\Set-ldapAdminPolicy.ps1 MaxPoolThreads 8
Here is a link on how to view/set via NTDSUtil.exe
How to view and set LDAP policy in Active Directory by using Ntdsutil.exe
The Code
$rootDSE = [ADSI]"LDAP://rootDSE"
$config = $rootDSE.configurationNamingContext
$queryPolicies = [adsi]"LDAP://CN=Default Query Policy,CN=Query-Policies,cn=Directory Service,cn=Windows NT,CN=Services,$config"
$oldvalue = $queryPolicies.lDAPAdminLimits | ?{$_ -match $policy}
$queryPolicies.PutEx(3,"lDAPAdminLimits",@("$policy=$count"))
$queryPolicies.Setinfo()
$queryPolicies.PutEx(4,"lDAPAdminLimits",@("$oldvalue"))
$queryPolicies.Setinfo()

