Hey guys! Today, we're diving deep into ADFS configuration step by step. Active Directory Federation Services (ADFS) is a crucial component for many organizations, enabling secure identity federation and single sign-on (SSO) capabilities. This guide provides a detailed, step-by-step walkthrough to help you successfully configure ADFS in your environment. Whether you're a seasoned IT pro or just starting out, this comprehensive guide will cover everything from initial setup to advanced configuration options. Let's get started!

Prerequisites

Before we jump into the actual configuration, let's ensure you have all the necessary prerequisites in place. These are crucial for a smooth and successful ADFS deployment. Think of it like gathering all your ingredients before you start baking a cake – you wouldn't want to realize halfway through that you're missing something important!

1. Active Directory Domain: A fully functional Active Directory domain is the backbone of your ADFS infrastructure. ADFS relies on AD for user authentication and directory services. Make sure your domain controllers are healthy and replicating properly. It's also a good idea to run dcdiag and repadmin to check the overall health of your AD environment. We need a working AD environment as the foundation for ADFS to manage identities and authenticate users seamlessly.
2. Server Hardware: You'll need at least one server to act as your ADFS server. The hardware requirements will depend on the size and complexity of your environment. For a small test environment, a virtual machine with 4GB of RAM and 2 CPUs might suffice. For production environments, carefully consider the expected load and plan accordingly. Ensure your server meets the minimum requirements specified by Microsoft for ADFS. Adequate hardware resources are vital for ADFS to perform efficiently, especially under heavy load. Insufficient resources can lead to performance bottlenecks and a poor user experience.
3. SSL Certificate: A valid SSL certificate is essential for securing communication between clients and the ADFS server. This certificate should be issued by a trusted Certificate Authority (CA). You can either use a public CA like DigiCert or Let's Encrypt, or an internal CA if you have one set up in your organization. The certificate should be installed on the ADFS server and bound to the ADFS service. Make sure the certificate's subject name matches the Federation Service Name you plan to use. An SSL certificate ensures that all communication between users and the ADFS server is encrypted, protecting sensitive information such as usernames and passwords. It's a critical security component.
4. Service Account: Create a dedicated service account in Active Directory to run the ADFS service. This account should have the necessary permissions to access AD and perform ADFS-related tasks. It's best practice to use a Group Managed Service Account (gMSA) for enhanced security. A gMSA automatically manages the password for the service account, reducing the risk of password-related issues. The service account is the identity under which the ADFS service runs, so it needs appropriate permissions to function correctly. Using a gMSA is highly recommended for improved security and manageability.
5. DNS Configuration: Ensure that you have the necessary DNS records configured to point to your ADFS server. This typically involves creating an A record for your Federation Service Name (e.g., fs.yourdomain.com) and pointing it to the IP address of your ADFS server. You may also need to configure a CNAME record for the enterpriseregistration subdomain if you plan to use Workplace Join. Proper DNS configuration is crucial for clients to be able to discover and access the ADFS service. Incorrect DNS settings can lead to connectivity issues and authentication failures.

With these prerequisites in place, you're well-prepared to move on to the next steps in the ADFS configuration process. Skipping or overlooking these prerequisites can lead to headaches down the road, so make sure you've got them covered!

Installing ADFS Role

Alright, with our prerequisites sorted, let's get to the fun part – installing the ADFS role. This is where we actually start setting up the ADFS server. Follow these steps carefully:

1. Open Server Manager: Launch Server Manager on the server you've designated as your ADFS server. Server Manager is your go-to tool for managing server roles and features in Windows Server. It provides a centralized interface for installing, configuring, and monitoring server components. You can usually find it pinned to your taskbar, or you can search for it in the Start Menu.
2. Add Roles and Features: In Server Manager, click on "Add roles and features." This will launch the Add Roles and Features Wizard, which will guide you through the process of installing the ADFS role. Make sure you have administrator privileges on the server to proceed. The wizard simplifies the installation process by presenting you with a series of options and prompts.
3. Select Installation Type: Choose "Role-based or feature-based installation" and click "Next." This option allows you to select specific roles and features to install on the server. The other option, "Remote Desktop Services installation," is for setting up a Remote Desktop Services environment.
4. Select Destination Server: Select the server on which you want to install the ADFS role. In most cases, this will be the local server. If you're managing multiple servers, you can select a remote server from the list. Verify that the selected server is the correct one before proceeding.
5. Select Server Roles: In the "Select server roles" screen, check the box next to "Active Directory Federation Services." This will select the ADFS role for installation. ADFS is the core component that provides identity federation and single sign-on capabilities. When you select ADFS, the wizard may prompt you to install additional features that are required for ADFS to function correctly.
6. Add Required Features: If prompted to add required features, click "Add Features." These features are dependencies that ADFS needs to operate correctly. The wizard will automatically select the necessary features based on the ADFS role. Ensure that all required features are selected before proceeding.
7. Confirmation: Review your selections and click "Install." The wizard will then begin the installation process. This may take a few minutes, depending on the speed of your server and the number of features being installed. Monitor the progress of the installation to ensure that it completes successfully. Once the installation is complete, you'll need to configure the ADFS service.

After the installation is complete, you're ready to move on to configuring the ADFS service. Keep an eye on the installation progress and make sure there are no errors. A successful installation is crucial for a smooth ADFS configuration experience.

Configuring ADFS

Okay, now that we've installed the ADFS role, it's time to configure it. This is where we define the settings that govern how ADFS will authenticate users and issue security tokens. Let's walk through the configuration steps:

1. Launch ADFS Management Console: After the ADFS role is installed, you'll see a notification in Server Manager prompting you to configure ADFS. Click on the "Configure the federation service on this server" link to launch the ADFS Management Console. Alternatively, you can find the ADFS Management Console in the Start Menu under "Administrative Tools." The ADFS Management Console is the primary tool for managing and configuring ADFS settings.
2. Select Federation Service Name: Choose a Federation Service Name. This is the publicly accessible name that clients will use to access the ADFS service (e.g., fs.yourdomain.com). The Federation Service Name should match the subject name on your SSL certificate. Ensure that the DNS record for the Federation Service Name points to the IP address of your ADFS server. The Federation Service Name is a critical component of the ADFS configuration, as it identifies your ADFS service to clients and applications.
3. Specify Service Account: Provide the service account that you created earlier for running the ADFS service. This account should have the necessary permissions to access Active Directory and perform ADFS-related tasks. As mentioned earlier, it's best practice to use a Group Managed Service Account (gMSA) for enhanced security. The service account is the identity under which the ADFS service runs, so it needs appropriate permissions to function correctly. Using a gMSA is highly recommended for improved security and manageability.
4. Specify SSL Certificate: Select the SSL certificate that you installed earlier. This certificate will be used to secure communication between clients and the ADFS server. Make sure the certificate is valid and trusted by clients. The SSL certificate ensures that all communication between users and the ADFS server is encrypted, protecting sensitive information such as usernames and passwords. It's a critical security component.
5. Specify Database: Choose the database to store the ADFS configuration. You can either use the Windows Internal Database (WID) or a SQL Server database. WID is suitable for small to medium-sized environments, while SQL Server is recommended for larger environments with high availability requirements. If you choose SQL Server, you'll need to provide the connection string to your SQL Server instance. The database stores the ADFS configuration, including trust relationships, relying party trusts, and attribute stores. The choice of database depends on the size and complexity of your ADFS deployment.
6. Review and Apply: Review your settings and click "Next" to apply the configuration. The ADFS Management Console will then configure the ADFS service based on your selections. This may take a few minutes to complete. Monitor the progress of the configuration to ensure that it completes successfully. Once the configuration is complete, you'll need to configure relying party trusts and other settings to integrate ADFS with your applications.

With these steps completed, your ADFS service should be up and running. Take a moment to celebrate – you've made significant progress! But don't get too comfortable; there are still a few more things to configure.

Configuring Relying Party Trusts

Now that ADFS is installed and configured, we need to set up Relying Party Trusts. A Relying Party Trust establishes a trust relationship between ADFS and an application that relies on ADFS for authentication. This allows users to sign in to the application using their ADFS credentials.

1. Open ADFS Management Console: If you don't already have it open, launch the ADFS Management Console. Navigate to "Relying Party Trusts" in the left-hand pane. The ADFS Management Console is your central tool for managing ADFS settings, including Relying Party Trusts.
2. Add Relying Party Trust: Click on "Add Relying Party Trust" in the right-hand pane. This will launch the Add Relying Party Trust Wizard, which will guide you through the process of creating a new Relying Party Trust. The wizard simplifies the process by presenting you with a series of options and prompts.
3. Select Data Source: Choose the data source for the Relying Party Trust. You can either enter the metadata URL of the application, import the metadata from a file, or manually enter the settings. If the application supports metadata, using the metadata URL or file is the easiest option. Otherwise, you'll need to manually configure the settings based on the application's requirements. The data source provides the information that ADFS needs to establish a trust relationship with the application.
4. Specify Display Name: Enter a display name for the Relying Party Trust. This is the name that will be displayed in the ADFS Management Console and in the sign-in page. Choose a descriptive name that clearly identifies the application. The display name helps you easily identify and manage the Relying Party Trust.
5. Configure Identifier: Configure the identifier for the Relying Party Trust. This is a unique URI that identifies the application. The identifier must match the identifier that the application sends to ADFS during authentication. Ensure that the identifier is unique across all Relying Party Trusts. The identifier is a critical component of the Relying Party Trust, as it ensures that ADFS correctly identifies the application during authentication.
6. Configure Access Control Policy: Configure the access control policy for the Relying Party Trust. This determines who is allowed to access the application. You can either allow all users or restrict access to specific users or groups. If you restrict access, you'll need to specify the Active Directory groups or users that are allowed to access the application. The access control policy allows you to control who can access the application through ADFS.
7. Configure Claim Rules: Configure the claim rules for the Relying Party Trust. Claim rules determine what information is sent to the application during authentication. You'll need to create claim rules to map Active Directory attributes to the claims that the application requires. For example, you might create a claim rule to send the user's email address, display name, or group membership to the application. Claim rules are essential for providing the application with the information it needs to authenticate and authorize users.
8. Review and Finish: Review your settings and click "Finish" to create the Relying Party Trust. The ADFS Management Console will then create the Relying Party Trust based on your selections. Once the Relying Party Trust is created, you can test the integration with the application to ensure that it's working correctly.

Configuring Relying Party Trusts is a crucial step in integrating ADFS with your applications. It allows users to seamlessly access applications using their ADFS credentials, providing a single sign-on experience. Make sure you carefully configure the settings and claim rules to ensure that the integration works correctly.

Testing ADFS

Finally, after all that configuration, it's time to test ADFS to make sure everything is working as expected. Testing is crucial to identify and resolve any issues before rolling ADFS out to production.

1. Access the ADFS Metadata: Open a web browser and navigate to the ADFS metadata URL. This is typically https://fs.yourdomain.com/federationmetadata/2007-06/federationmetadata.xml. If you can access the metadata XML file, it means that your ADFS server is reachable and the basic configuration is working. The ADFS metadata contains information about the ADFS service, including its endpoints, certificates, and supported protocols.
2. Test with a Relying Party Application: Try accessing an application that you've configured with a Relying Party Trust. This will test the entire authentication flow, from the application redirecting the user to ADFS, to ADFS authenticating the user, and then redirecting the user back to the application. Ensure that the user is able to successfully sign in to the application using their ADFS credentials. If you encounter any errors, check the ADFS logs for more information.
3. Check ADFS Logs: The ADFS logs contain valuable information about authentication events, errors, and warnings. You can find the ADFS logs in the Event Viewer under "Applications and Services Logs" > "AD FS" > "Admin." Review the logs for any errors or warnings that might indicate a problem with the ADFS configuration. The ADFS logs are your go-to resource for troubleshooting ADFS issues.
4. Use the Test-ADFSAuthentication Cmdlet: Use the Test-ADFSAuthentication cmdlet in PowerShell to test ADFS authentication. This cmdlet allows you to simulate an authentication request and verify that ADFS is able to successfully authenticate the user. You can specify the username, password, and relying party trust to use for the test. The Test-ADFSAuthentication cmdlet is a powerful tool for testing ADFS authentication from the command line.

By thoroughly testing ADFS, you can ensure that it's working correctly and that users are able to seamlessly access applications using their ADFS credentials. Don't skip this step – it's essential for a successful ADFS deployment!

Conclusion

And there you have it, guys! A comprehensive guide to ADFS configuration step by step. We've covered everything from the initial prerequisites to installing the ADFS role, configuring the service, setting up Relying Party Trusts, and testing the deployment. ADFS is a powerful tool for enabling secure identity federation and single sign-on, and with this guide, you should be well-equipped to successfully configure ADFS in your environment. Remember to carefully plan your deployment, follow the steps closely, and thoroughly test your configuration. Good luck!