Overview
This guide provides a comprehensive walkthrough for setting up and configuring Multi-Factor Authentication (MFA) within Azure Active Directory (Azure AD). MFA adds an extra layer of security to your sign-in process, significantly reducing the risk of unauthorized access.
By requiring users to provide at least two verification factors, MFA helps protect sensitive data and applications by making it harder for attackers to gain access, even if they have stolen user credentials.
Prerequisites
- An active Azure subscription with Azure AD configured.
- Global Administrator or Security Administrator privileges in your Azure AD tenant.
- Access to the Azure portal (portal.azure.com).
- Understanding of your organization's security policies and user roles.
Configuration Steps
Configuring Azure AD MFA can be done through Conditional Access policies or by enabling it per-user. Conditional Access is the recommended modern approach.
Using Conditional Access Policies (Recommended)
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Navigate to the Azure Active Directory portal and select Conditional Access under the 'Security' section.
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Click on New policy.
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Give your policy a descriptive name (e.g., "Require MFA for All Users").
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Under Assignments:
- Users and groups: Select the users or groups this policy will apply to. You can choose 'All users' or specific groups. Consider excluding break-glass accounts.
- Target resources: Select the cloud apps or actions the policy will apply to. 'All cloud apps' is a common choice for broad security.
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Under Access controls:
- Grant: Click on Grant access.
- Select Require multi-factor authentication.
- You can choose to require it for 'all selected controls' or allow specific methods.
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Under Enable policy, set it to On.
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Click Create to save the policy.
Tip: Start by targeting a pilot group of users to test the policy before rolling it out to all users.
Enabling MFA Per User (Legacy Method)
While Conditional Access is preferred, you can still manage MFA settings on a per-user basis for older scenarios or specific requirements.
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Navigate to the Azure Active Directory portal and select Users.
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Click on Multi-factor authentication (under 'Manage').
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Select the users you want to enable MFA for.
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Under quick steps on the right-hand side, click Enable.
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Confirm by clicking enable multi-factor authentication.
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Users will be prompted to register their MFA methods on their next sign-in.
User Setup and Registration
Once MFA is enabled for users, they will need to register their preferred authentication methods. This typically happens during their first sign-in after MFA is enforced.
Allowed Authentication Methods:
- Microsoft Authenticator App: Recommended for its security and ease of use (push notifications, code).
- Phone Call: A voice call to a registered phone number.
- Text Message (SMS): A verification code sent via SMS.
- Security Key: A physical hardware token (e.g., FIDO2 security key).
- App Password: For older applications that do not support MFA directly. (Use sparingly).
User Registration Process:
- Users sign in to an Azure AD-protected application.
- They will be prompted to set up their security info.
- They follow the on-screen prompts to choose and configure their preferred MFA method(s).
- Users can manage their MFA methods by visiting mysecurityinfo.microsoft.com.
Best Practices
- Enable MFA for all users: A robust security posture requires MFA for everyone.
- Use Conditional Access: Leverage Conditional Access for flexible and granular control over MFA enforcement.
- Promote Microsoft Authenticator: Encourage users to use the Microsoft Authenticator app for its security and user experience.
- Educate Users: Clearly communicate the importance of MFA and provide clear instructions on how to register and use it.
- Exclude Break-Glass Accounts: Create and protect emergency access accounts (break-glass accounts) with strong passwords and monitor their usage closely. Do not enforce MFA on these accounts via Conditional Access if it might lock you out.
- Regularly Review Policies: Periodically review your Conditional Access policies and MFA settings to ensure they align with your organization's evolving security needs.
- Monitor Sign-in Logs: Utilize Azure AD sign-in logs to monitor MFA usage and detect any suspicious activity.