Watch AD for changes

WatchADForChanges.ps1

$lastHighestUSN = 0
$rootDSE = [ADSI]("LDAP://RootDSE")
$lastHighestUSN = $rootDSE.highestCommittedUSN
"Starting highest USN: " + $lastHighestUSN
$configNC = [ADSI]("LDAP://" + $rootDSE.configurationNamingContext)
while ($true)
{
	$rootDSE = [ADSI]("LDAP://RootDSE")
	$highestUSN = $rootDSE.highestCommittedUSN
	if ($lastHighestUSN -lt 1) { $lastHighestUSN = $highestUSN }
	if ($highestUSN -gt $lastHighestUSN)
	{
        "New highest USN: " + $highestUSN
		$filter = "(&(USNChanged >= " + $lastHighestUSN + ")(USNChanged <= " + $highestUSN + "))"
		$finder = new-object System.DirectoryServices.DirectorySearcher($configNC, $filter)
		$finder.PageSize = 100
		$results = $finder.FindAll()
		if ($results.Count -gt 0)
        {
            "Objects changed:"
		    foreach ($result in $results)
		    {
			    $result.Path
		    }
        }
        else
        {
            "No objects changed in Config context."
        }
	}

    $lastHighestUSN = $highestUSN
	Start-Sleep 1
}