Azure Active Directory Seamless Single Sign-On: Quick start

How to deploy Seamless SSO

Azure Active Directory Seamless Single Sign-On (Azure AD Seamless SSO) automatically signs users in when they are on their corporate desktops connected to your corporate network. It provides your users easy access to your cloud-based applications without needing any additional on-premises components.

Important

The Seamless SSO feature is currently in preview.

To deploy Seamless SSO, you need to follow these steps:

Step 1: Check prerequisites

Ensure that the following prerequisites are in place:

  1. Set up your Azure AD Connect server: If you use Pass-through Authentication as your sign-in method, no further action is required. If you use Password Hash Synchronization as your sign-in method, and if there is a firewall between Azure AD Connect and Azure AD, ensure that:
  2. You are using versions 1.1.484.0 or later of Azure AD Connect.
  3. Azure AD Connect can communicate with *.msappproxy.net URLs and over port 443. This prerequisite is applicable only when you enable the feature, not for actual user sign-ins.
  4. Azure AD Connect can make direct IP connections to the Azure data center IP ranges. Again, this prerequisite is applicable only when you enable the feature.
  5. You need Domain Administrator credentials for each AD forest that you synchronize to Azure AD (using Azure AD Connect) and for whose users you want to enable Seamless SSO.

Step 2: Enable the feature

Seamless SSO can be enabled using Azure AD Connect.

If you are doing a fresh installation of Azure AD Connect, choose the custom installation path. At the "User sign-in" page, check the "Enable single sign on" option.

Azure AD Connect - User sign-in

If you already have an installation of Azure AD Connect, choose "Change user sign-in page" on Azure AD Connect and click "Next". Then check the "Enable single sign on" option.

Azure AD Connect - Change user sign-in

Continue through the wizard until you get to the "Enable single sign on" page. Provide Domain Administrator credentials for each AD forest that you synchronize to Azure AD (using Azure AD Connect) and for whose users you want to enable Seamless SSO.

After completion of the wizard, Seamless SSO is enabled on your tenant.

Note

The Domain Administrator credentials are not stored in Azure AD Connect or in Azure AD, but are only used to enable the feature.

Follow these instructions to verify that you have enabled Seamless SSO correctly:

  1. Sign in to the Azure Active Directory admin center with the Global Administrator credentials for your tenant.
  2. Select Azure Active Directory on the left-hand navigation.
  3. Select Azure AD Connect.
  4. Verify that the Seamless Single Sign-On feature shows as Enabled.

Azure portal - Azure AD Connect blade

Step 3: Roll out the feature

To roll out the feature to your users, you need to add two Azure AD URLs (https://autologon.microsoftazuread-sso.com and https://aadg.windows.net.nsatc.net) to users' Intranet zone settings via Group Policy in Active Directory.

Note

The following instructions only work for Internet Explorer and Google Chrome on Windows (if it shares set of trusted site URLs with Internet Explorer). Read the next section for instructions to set up Mozilla Firefox and Google Chrome on Mac.

Why do you need to modify users' Intranet zone settings?

By default, the browser automatically calculates the right zone (Internet or Intranet) from a URL. For example, http://contoso/ is mapped to the Intranet zone, whereas http://intranet.contoso.com/ is mapped to the Internet zone (because the URL contains a period). Browsers don't send Kerberos tickets to a cloud endpoint - like the two Azure AD URLs - unless its URL is explicitly added to the browser's Intranet zone.

Detailed steps

  1. Open the Group Policy Management tool.
  2. Edit the Group Policy that is applied to some or all your users. In this example, we use the Default Domain Policy.
  3. Navigate to User Configuration\Administrative Templates\Windows Components\Internet Explorer\Internet Control Panel\Security Page and select Site to Zone Assignment List. Single sign-on
  4. Enable the policy, and enter the following values (Azure AD URLs where Kerberos tickets are forwarded) and data (1 indicates Intranet zone) in the dialog box.

     Value: https://autologon.microsoftazuread-sso.com
     Data: 1
     Value: https://aadg.windows.net.nsatc.net
     Data: 1
    
    Note

    If you want to disallow some users from using Seamless SSO - for instance, if these users are signing in on shared kiosks - set the preceding values to 4. This action adds the Azure AD URLs to the Restricted Zone, and fails Seamless SSO all the time.

  5. Click OK and OK again.

Single sign-on

Browser considerations

Mozilla Firefox

Mozilla Firefox doesn't automatically do Kerberos Authentication. Each user has to manually add the Azure AD URLs to their Firefox settings using the following steps:

  1. Run Firefox and enter about:config in the address bar. Dismiss any notifications that you see.
  2. Search for the network.negotiate-auth.trusted-uris preference. This preference lists Firefox's trusted sites for Kerberos authentication.
  3. Right-click and select "Modify".
  4. Enter "https://autologon.microsoftazuread-sso.com, https://aadg.windows.net.nsatc.net" in the field.
  5. Click "OK" and reopen the browser.

Safari on Mac OS

Ensure that the machine running Mac OS is joined to AD. See instructions on how to do that here.

Google Chrome on Mac OS

For Google Chrome on Mac OS and other non-Windows platforms, refer to this article for information on how to whitelist the Azure AD URLs for integrated authentication.

Using third-party Active Directory Group Policy extensions to roll out the Azure AD URLs to Firefox and Google Chrome on Mac users is outside of this article's scope.

Known limitations

Seamless SSO doesn't work in private browsing mode on Firefox and Edge browsers. It also doesn't work on Internet Explorer if the browser is running in Enhanced Protection mode.

Important

We recently rolled back support for Edge to investigate customer-reported issues.

Step 4: Test the feature

To test the feature for a specific user, ensure that all the following conditions are in place:

  • The user is signing in on a corporate device.
  • The device has been previously joined to your Active Directory (AD) domain.
  • The device has a direct connection to your Domain Controller (DC), either on the corporate wired or wireless network or via a remote access connection, such as a VPN connection.
  • You have rolled out the feature to this user using Group Policy.

To test the scenario where the user enters only the username, but not the password:

To test the scenario where the user doesn't have to enter the username or the password:

Step 5: Roll over keys

In Step 2, Azure AD Connect creates computer accounts (representing Azure AD) in all the AD forests on which you have enabled Seamless SSO. Learn more in detail here. For improved security, it is recommended that you frequently roll over the Kerberos decryption keys of these computer accounts.

Important

You don't need to do this step immediately after you have enabled the feature. Roll over the Kerberos decryption keys at least every 30 days.

Next steps