Category Archives: ADDS

How to allow users to join their computers into AD domain

Imagine, that half of your company users are local administrators at their machines. They pretty often reinstall operating systems and request IT Service Desk to join that newly installed OSes into corporate Active Directory domain. One usually has two options to help the users: either to come to the user’s workstation and use one’s credentials to join a PC into domain, or to recreate workstation’s computer account, at the same time allowing employee’s user account to join the computer into a domain by him-/herself. In the first case, ServiceDesk employee needs to walk to a user’s desk, which may be quite exhausting, especially for remote locations, in the second case, computer’s group membership will be probably lost and a new account must be added into all appropriate groups manually.
Is it possible to decrease time and effort put into resolution of such requests? Yes, absolutely!

The main trick is to assign a user with following permissions to his computer’s account:

  • Validated write to DNS host name
  • Validated write to service principal name
  • List the children of an object
  • Read
  • Read security information
  • List the object access
  • Control access right
  • Delete an object and all of its children
  • Delete
  • Write to the following properties:
    • sAMAccountName
    • displayName
    • description
    • Logon Information
    • Account Restrictions

User with abovementioned permissions will be able to join their PC into an AD domain without any assistance from Service Desk.

I made this little script to automate the permissions assigning. Please look into the help section (or use Get-Help cmdlet) to find out about its syntax and usage examples.

In case you use Windows 8.1/Server 2012 R2, you might need to install KB 3092002, either way, only member of the “Domain Admins” group will be able to execute the script. This is due to a bug in the Set-Acl cmdlet. The fix for Windows 10 is included in the latest RSAT package.

If you unsure how to use the script or experience any errors, please leave a comment below or contact me directly.

“setspn -x” is case-insensitive now

As you probably know, duplicate SPNs cause Kerberos authentication errors in AD DS domains. You may notice it by looking for KRB_AP_ERR_MODIFIED errors and Event ID 11 in system logs. With Windows Server 2008, Microsoft released a largely improved version of setspn, which includes “-x” switch to help you proactively monitor your infrastructure for duplicate SPNs. Combined with “-f” switch, setspn output contains duplicate SPNs not only from a single domain, but from a whole AD DS forest. Many companies rely on a result of “setspn -x -f” command as a data source for monitoring systems.

Today I found, that all these years almost nobody noticed that “setspn -x” command compares SPNs case-sensitively, i.e. following SPNs will be considered different and will not be shown in the output:

  • HOST/ServerName

Starting from Windows 10, Microsoft changed behavior of setspn to case-insensitive, and, from now on, every duplicated SPN will be displayed in setspn output, disregarding its case.

While Microsoft asserts, that Windows is case-insensitive to SPNs, not every Microsoft product agrees: for example, Shane Young found that you must pay attention to SPNs used by SharePoint accounts.

As a conclusion, I suggest every AD DS administrator to check their infrastructure with the setspn tool shipped with Windows 10, at least once. It allows you to find TRULY EVERY duplicate SPN (I did found a couple, myself ;).

AuthenticationSilo claim is not issued

You setup an Active Directory Authentication Policy and use a membership in Authentication Policy Silo as an access control condition. Next you setup Authentication Policy Silo to use the abovementioned Authentication Policy for appropriate principal types. You set the silo into “audit-only” mode.

In that case, AuthenticationSilo claim is not issued for your security principals.

Why does this happen?

As described in GetAuthSiloClaim section of Active Directory Technical Specification, AuthenticationSilo claim is issued only when policies in Authentication Silo are enforced:
Check if user is assigned to an enforced silo.
assignedSilo := pADPrincipal!msDS-AssignedAuthNPolicySilo
if (assignedSilo = NULL ||
assignedSilo!msDS-AuthNPolicySiloEnforced = FALSE)
return NULL


I’ve found no option to modify this behavior yet. Just keep it in mind while you are testing your Authentication Policies configuration.

SCCM: Device Collection Based On a Local Group Membership

New task came up recently – I need to separate in SCCM self-managed workstations from IT-managed ones. We define following criteria for IT-managed workstations: no other accounts are in local Administrators group except for built-in Administrator, Domain Admins group and a group for Service Desk administrators. All workstations are located in the same OU, so I cannot use OU-based collections.

As you may know, SCCM 2012 doesn’t have built-in tools to get local groups membership. Thanks to Sherry Kissinger who solved this problem for us using Compliance Settings. After you install her package, you’ll get a new Configuration Baseline and Configuration Item in SCCM console named as “WMI Framework For Local Groups with Logging” and “Local Group Members into WMI with Logging”. This package also creates 2 new tables and 1 view into SCCM database: LocalGroupMembers_DATA, LocalGroupMembers_HIST and v_GS_LocalGroupMembers0.

After creating and deploying baseline, you can use v_GS_LocalGroupMembers0 view to create reports based on local groups membership.
Don’t forget: you must not deploy that baseline to domain controllers! For example, you can create a collection which includes all your systems except domain controllers: create new device collection using All Systems as limiting collection and add it with include rule, then add All Domain Controllers collection with exclude rule. You can download MOF-file for such collection here.

Unfortunately, neither LocalGroupMembers_DATA, nor v_GS_LocalGroupMembers0 can be used in WQL-queries when you create a collection.
Am I stuck? Let’s review what do I had for now:

  • I have all data about local groups membership in custom table.
  • I can create any reports using that data.
  • I can create collections using data from standard tables in SCCM DB.
  • But I cannot create collections based on a data from custom SQL-tables.

I need a way to put data from table LocalGroupMembers_DATA into standard SCCM tables and PowerShell is here to save the day.
There are at least two ways to get data from SQL with PowerShell:

  1. Connect to DB directly and use T-SQL queries with SQL cmdlets.
  2. Connect to SQL Server Reporting Services using New-WebServiceProxy cmdlet. Stefan Stranger and Jin Chen wrote an example script to achieve it.

With PowerShell we can do anything with that SQL-data. Our goal is to populate device collections with workstations and here we go again with two different options:

  1. We can add computers into group in AD DS and then create a device collection using this group. For this method to work you need to activate Active Directory Group Discovery discovery method for site and domain where AD group will reside.
  2. Add computers into collection directly using Add-CMDeviceCollectionDirectMembershipRule cmdlet.

Since both group and a report will be useful for me in the future, I’m stick with them.

Now our scenario looks like this:

  1. Activate Active Directory Group Discovery.
  2. Collect local group membership using Compliance Settings.
  3. Create a report with gathered data an any SSRS.
  4. Get names of computers from this report with New-WebServiceProxy cmdlet.
  5. Add these computers into an AD group.
  6. Create a device collection by that AD group.

I build a report where I list all computers don’t comply with conditions discussed earlier.
Here is what first DataSet query looks like:

It can be easily expanded to include another set of groups to ignore.
Mind CompOU parameter: in web-interface you can select multiple OUs where to search computers.
To get a full list of OUs from a forest, you can use another query:

I modified RenderSQLReportFromPosh.v1.000.ps1 so it could populate AD DS group in addition to get data from reports. Here’s its code:

My modified script receives a report from $URL and $ReportPath locations, compares a list from it with members of $GroupName AD DS group and adds/removes computers from that group until it and the report would be the same.
You can find a path for log of actions in $Log variable. Here, script records all computers which were added or removed from the group.
OUs to search are defined into $param1 and $param2 variables. If you need more OUs, create a new parameter variables and do not forget to add them into $parameters.

As last, I created standard device collection based on AD group $GroupName.

You can download report as an RDL-file and a script here. Do not forget to create DataSource in the report to connect to your SSRS instance.

SCCM: All Domain Controllers Collection

There are many ways to create a collection containing all domain controllers. Here are some examples:

By a role of a computer:

By the primary AD DS group:

By AD DS group name:

I personally prefer the first version, by a role of a computer. You can download a MOF-file for this collection here. Just import it as described in How to Create Collections in Configuration Manager article and new “All Domain Controllers” collection will appear in your SCCM console.