If you run into errors stating that the server you are logging into cannot pull or connect to the RDS licensing server check to see how you are connecting to it.
For example if you are using a CNAME “alias” record to get to the server you may run into issues with DNS resolution and proper authentication.
The SRV records for KMS in DNS can be found by launching a command prompt and entering “nslookup”.
Then run: “set type=all” so all records are returned.
Then the record you want to look up is: “_vlmcs._tcp.domain.suffix”
This should return all of the SRV records for KMS services. This is an important area in DNS to watch because if boxes can add themselves to DNS, anyone who installs the Volume License Services could get a record entered here.
In this particular example we have three SRV records.
We ran into an issue updating our Domain Controllers from Windows Update. This appears to be profile based at first troubleshooting. A different Domain Administrator could pull down updates without any issue.
Still investigating… but if google directs you here, try another DA account.
If you have your servers domain joined and are therefore using WSUS to push Windows Updates, you may receive this error message when trying to add features that use Windows Update Services.
You can bypass your local WSUS server and let the box pull down the .NET features from Microsoft directly by changing the following RegKey.
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
Set the Value: UseWUServer —> 0 and restart the Windows Update Service.
Revert these changes when you are done and restart Windows Update Service.
This blog is only providing the information needed to replace the WAP/ADFS servers with new servers running 2019. This article is not providing any information on upgrading the farm behavior level.
Always do this in a test environment before affecting Production
Mircosoft ADFS requirements link: https://learn.microsoft.com/en-us/windows-server/identity/ad-fs/overview/ad-fs-requirements
WAP Server Replacement:
Use whatever mechanisms you have through your load-balancing infrastructure to drain one of the WAP servers so nobody is accessing it.
In Server Manager launch “Remote Access Management”
Verify you see the number of Clustered WAPs servers you should here.
You can also verify this with PowerShell by running the following command in an Administrative Powershell: Get-WebApplicationProxyConfiguration.
Look at the “ConnectedServersName” field, here I have two.
Remove the box that you are currently logged into from the ConnectedServersName property object by running the following PowerShell:
Set-WebApplicationProxyConfiguration -ConnectedServersName ((Get-WebApplicationProxyConfiguration).ConnectedServersName -ne ‘servername.domain.suffix’)
[-ne means not equal, you want to put the server you want to remove in place of ‘servername.domain.suffix’]
You can then verify by running Get-WebApplicationProxyConfiguration again and see that the server has disappeared.
I only have two WAPs so at this point both nodes are still servicing requests but only one node is left in the settings. You can now shutdown the node you removed and bring up a new 2019 server with the same name/IP and bind into the already existing AD Object.
Once this box is up login with a Domain Admin account and Add Roles/Features and add the “Remote Access” Server Role
Choose “Web Application Proxy” on the Role Services tab. You may be prompted to accept installing additional features, go ahead and click Add Features.
Once this is complete and before you launch the Web Application Proxy Wizard, we need to get the ADFS certificate loaded onto this box.
Go to another ADFS node that has the certificate and export the certificate. This certificate should be in the Personal\Certificates area of the Local Machine.
Export the certificate
Import the Certificate on the server you are currently working on into the Personal\Certificates Certificate Store of the Local Machine.
Now you are ready to Open the Web Application Proxy Wizard”
Choose the Certificate we imported it should be in the drop down.
Before you hit “Configure” depending on how your DNS is configured you need to make sure the WAP server can get to your adfs servers using the primary DNS name. For us this involved some HOSTS file magic.
Click “Configure” and you should see the Web Application Proxy Configuration completed successfully.
VERIFY everything is up and working and this new node is servicing requests. You should also see now that Remote Access Manager and the Powershell configuration once again shows two nodes participating.
Repeat this process to take down any other WAPs.
ADFS Server Replacement:
Login to any of the federation servers that are not currently the Primary Node. You will know this by launching the ADFS Management Console.
Go to Server Manager, Manage -> Remove Roles & Features
Uncheck Active Directory Federation Services.
Click Next, Next, Next…… Finish
Reboot to finish the removal process.
Shutdown this box and bring up another box with the same name, IP, configuration. Bind it to the domain and take over the old AD object.
Login as a “Domain Admin” and Go to Server Manager, Add Roles & Features
Click “Install” and then configure the federation services on this server.
Specify the FQDN of the Primary Node of your Active Directory Federated Services. (Servername.Domain.Suffix)
Note** Like we did on the WAP servers make sure the certificate is loaded onto the Local Machine Personal Certificates Store on this box before continuing.
Choose the SSL Certificate you imported
Specify a domain user account or group managed service account. In this particular example this is a domain user account. If you use a domain user account make sure it is a local administrator of the server.
[I’m checking on this local administrator may not be needed anymore].
NOTE** If you are locking down firewall rules, before configuration can run verify that Port 80 can be accessed on the primary node from this server. If you receive DNS errors here it could be Port 80, and not actually DNS.
Reboot.
Verify this node is now accepting requests.
Perform these steps on every other ADFS node that is not the primary node. Once complete, continue to migrate Primary Node to a node that was already replaced so primary node can be upgraded.
Migrate Primary Node to a Replaced Node:
Pick a node that has already been replaced that you want to migrate the primary node to. On this node run the following:
Set-AdfsSyncProperties -Role PrimaryComputer
If you perform a Get-AdfsSyncProperties both before and after you should see the role change.
Now you need to go the original primary node owner and run the following:
Set-AdfsSyncProperties -role SecondaryComputer -PrimaryComputerName newprimary.domain.suffix
You will want to wait about 5 minutes and make sure when you run Get-AdfsSyncProperties that you are actually seeing a successful last sync come from the new primary node before you take down the original primary node.
You can now repeat the process listed here to replace the original primary node. If you want to migrate the primary node back when you are done you can follow these instructions again.
There are many security risks with running Active Directory. In the Year 2022, one of these is still running your Active Directory with unsigned/simple ldap binds.
If you don’t already have a PKI environment setup you should probably work to set one up so you can get certificates on your Domain Controllers that are trusted by your businesses devices so unsigned/simple binds can be retired.
A script I’ve found very helpful for monitoring the Domain Controller firewall logs for these events is located here:
https://github.com/russelltomkins/Active-Directory/blob/master/Query-InsecureLDAPBinds.ps1
Here is the Microsoft Article on enabling LDAP signing:
Here is the Microsoft Article from 2020 regarding the changes they were planning on making to turn this feature off.
You can enable LDAP over SSL with a third-party certification authority if you don’t have your own PKI.
I’ll have another blog forthcoming regarding setting up an in-house PKI securely.
As I’m migrating Domain Controllers over to Server Core one of the major issues I’ve run into is managing the Windows Firewall Rules. On a GUI version of Windows Server it is very easy to see what firewall rules are applied, in core… not so much, especially if you are pushing them with GPO (Group Policy).
All of the PowerShell cmdlets and netsh advfirewall commands all seem to return the local firewall rules and not any of the Group Policy pushed firewall rules. Moreover I could not find an easy way to see what the current firewall rules are that are applied via GPO.
As I have disabled all of the built-in firewall rules as to lock down the Domain Controller Firewall Rules as tightly as possible, even with RPC open and the dynamic RPC range locked to specific ports but open the Windows Firewall MMC would not open. I was seeing no blocked traffic in the Windows Firewall Logs.
I received the following error message:
“There was an error opening the Windows Firewall with Advanced Security snap-in”
“The specified computer could not be remotely managed. Ensure that you are not trying to connect to a remote computer with an earlier version of Windows…..”
My solution to this problem was to enable the built-in Firewall Rules for Remote Firewall Management so you can use MMC console:
Windows Firewall Remote Management (RPC)
Windows Firewall Remote Management (RPC-EPMAP)
These firewall rules seem to have some special magic to them that I haven’t put my finger on yet that allow the Remote MMC Firewall snap-in to work. You can of course lock these rules down to remote IPs as well.
I’m putting together a blog post for easy access to Windows Server Core tasks.
View Installed Programs (PowerShell):
Get-WMIObject Win32_SoftwareFeature|Select ProductName,Caption,Version|FT
Request New Certificate (PowerShell):
Get-Certificate -Template “_TEMPLATENAME” -SubjectName “CN = SERVERNAME.domain.suffix” -CertStoreLocation cert:\LocalMachine\My
In my previous blog (https://paularquette.com/windows-server-firewall-logging-via-gpo-log-file-not-created/) I mentioned that simply turning on Group Policy for the Windows Firewall doesn’t actually create the firewall logs.
In order to force create the windows firewall logs for servers that are already out there in the wild I have created a batch script that can be ran in Group Policy as a startup script.
The script is located on my github but I’ve listed here as well because it is a small script. For the latest updates though please visit github as it is unlikely I will individually update this blog post.
https://github.com/paularquette/Windows-Servers/blob/main/CreateFirewallLogs.bat
rem Batch Script to Create Firewall Log Files
rem Written By: Paul Arquette
rem Last Modified: Oct 24, 2022
rem Last Modified For: Github
if exist C:\Windows\System32\LogFiles\firewall\pfirewall.log (
echo file exists
) else (
netsh advfirewall set allprofiles logging filename %systemroot%\System32\LogFiles\firewall\pfirewall.log
netsh advfirewall set allprofiles logging maxfilesize 32767
netsh advfirewall set allprofiles logging droppedconnections enable
netsh advfirewall set allprofiles logging allowedconnections enable
)Did you apply a Windows Firewall Policy that blocks the ability to talk to Active Directory and get Group Policies? We all make mistakes….
¯\_(ツ)_/¯
You can no longer login to this box with Active Directory Credentials…..
You try to login as a local administrator and see that everything is grayed out?
On top of that you also turned off the ability to apply local firewall rules?
Don’t fear! There is a way to fix this as long as you have Local Admin rights on the box. Open up the Registry Editor and navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall
Right-Click the WindowsFirewall key and delete it and all sub-keys and reboot.
This should fix the issue and you will pull down the corrected Group Policy on reboot.