Introduction
Azure Active Directory (Azure AD) Application Proxy is a feature that enables users to access on-premises applications from outside your corporate network. It provides a secure, pre-authenticated way to connect to your internal web applications without requiring a VPN, enhancing both user experience and security posture.
This guide will walk you through the essential steps to set up and configure Azure AD App Proxy for your organization.
Prerequisites
- An Azure AD Premium P1 or P2 license.
- An on-premises application published on the web that you want to make accessible remotely.
- A server on your on-premises network to install the App Proxy Connector.
- Administrative access to your Azure AD tenant and the on-premises network.
Step 1: Install the Azure AD App Proxy Connector
The App Proxy Connector is a lightweight agent that runs on an on-premises server and acts as a bridge between Azure AD and your internal application.
Navigate to Azure Active Directory in the Azure portal.
Under Application Management, select Application Proxy.
Click Download connector service executable and follow the on-screen instructions to download and install the connector on your chosen on-premises server.
During installation, you'll be prompted to sign in with your Azure AD administrator credentials. Ensure the connector registers successfully.
Step 2: Publish Your On-Premises Application
Once the connector is installed and active, you can publish your application through App Proxy.
In the Azure portal, navigate to Azure Active Directory > Enterprise applications > New application.
Under Add an application, select On-premises application.
Fill in the application details:
- Name: A user-friendly name for your application (e.g., "Internal CRM").
- Internal URL: The URL users access when they are inside your corporate network.
- External URL: The URL users will use to access the application from outside. This is typically a custom domain.
- Pre-authentication: Choose Azure Active Directory for the best security.
- Connector Group: Select the group your connector belongs to.
Click Add to create the application.
Step 3: Configure Single Sign-On (SSO)
Azure AD App Proxy integrates seamlessly with Azure AD's SSO capabilities, allowing users to authenticate once and access multiple applications.
From the Enterprise application page, select Single sign-on.
Choose your preferred SSO method. For many internal applications, Header-based SSO or Password-based SSO might be suitable. For modern applications supporting SAML or OpenID Connect, these are preferred.
Follow the specific configuration steps for your chosen SSO method. This often involves mapping user attributes or providing credentials.
Step 4: Assign Users and Groups
Control who can access the published application by assigning users and groups.
Go back to your application's overview page in the Azure portal.
Select Users and groups.
Click Add user/group and select the users or groups you want to grant access to.
Best Practices and Advanced Configurations
To maximize the benefits of Azure AD App Proxy, consider these points:
- Connector Management: Deploy multiple connectors for high availability and load balancing. Keep connectors updated to the latest version.
- External URLs: Use custom domains for a professional and recognizable external URL.
- Conditional Access: Leverage Azure AD Conditional Access policies to enforce granular access controls, such as multi-factor authentication (MFA) or device compliance.
- Application-Specific Instructions: Some applications may require specific configurations within App Proxy settings, such as custom HTTP headers or detailed SSO settings. Refer to the Azure documentation for specific application types.
- Security: Always use pre-authentication with Azure AD. Ensure your internal URLs are not directly exposed to the internet.
"Azure AD Application Proxy is a powerful tool for securely extending access to internal applications, significantly reducing the complexity of remote access solutions."
Troubleshooting Common Issues
If you encounter problems, check the following:
- Connector Status: Ensure the connector service is running on the on-premises server and appears as 'Active' in the Azure portal.
- Firewall Rules: Verify that the on-premises server can communicate with Azure AD endpoints and your internal application.
- URL Configuration: Double-check both the internal and external URLs for typos and correct protocols (HTTP/HTTPS).
- SSO Configuration: Review the SSO settings for any misconfigurations, especially attribute mappings or credential storage.