Securing On-Premises Virtual Machines with Azure Application Proxy
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Securing On-Premises Virtual Machines with Azure Application Proxy

Azure Application Proxy is a service that allows organizations to securely access web applications that are hosted on-premises, behind a firewall. It enables users to access applications from anywhere and on any device, while providing an additional layer of security for the on-premises resources. In this blog post, we will discuss how to use Azure Application Proxy for authentication to a virtual machine in an on-premise setup.

Before diving into the setup process, let's first understand what Azure Application Proxy is and how it works. Azure Application Proxy is a feature of Azure Active Directory (AD) that allows organizations to securely access on-premises web applications from anywhere. It works by installing a lightweight service called the Application Proxy Connector on an on-premises server, which connects to Azure AD to authenticate users and pass their requests to the on-premises applications. The connector is responsible for encrypting the traffic between the user and the on-premises application, ensuring that the data remains secure.

Now that we have a basic understanding of Azure Application Proxy, let's discuss the steps required to set it up for authentication to a virtual machine in an on-premise setup.

  1. Configure the Azure Application Proxy Connector on the on-premises server: The first step in setting up Azure Application Proxy for authentication to a virtual machine is to install and configure the Application Proxy Connector on an on-premises server. The connector is a lightweight service that runs on Windows Server and connects to Azure AD to authenticate users and pass their requests to the on-premises applications. To install the connector, you can download the installer from the Azure portal and run it on the on-premises server. Once the connector is installed, you will need to configure it with the necessary settings, such as the tenant ID, connector ID, and connector secret.
  2. Create an Azure Application Proxy Application: After configuring the connector, the next step is to create an Azure Application Proxy application. To do this, navigate to the Azure AD Application Proxy section in the Azure portal, and create a new application. Provide a name and a sign-on URL for the application, and select the connector that you installed in step 1. This will create an application in Azure AD that you can use to authenticate users to the virtual machine.
  3. Configure the Virtual Machine to use Azure Application Proxy: Once the application is created, you will need to configure the virtual machine to use the Application Proxy. This can be done by modifying the application's settings to use the Application Proxy URL, which can be found in the Azure portal. The Application Proxy URL is the endpoint that users will use to access the virtual machine. It acts as a reverse proxy, forwarding the user's request to the on-premises application after authentication.
  4. Create a Group Policy and configure the connector with it: In order to ensure that the connector is configured correctly, it's a good practice to create a Group Policy and configure the connector with it. This can be done by creating a new Group Policy Object (GPO) and linking it to the on-premises server where the connector is installed. In the GPO, you will need to configure the connector with the tenant ID, connector ID, and connector secret. This will ensure that the connector is configured correctly, even if the server is rebooted or the connector service is restarted.
  5. Assign users to the Application: After configuring the connector and the virtual machine, the next step is to assign users or groups to the application, so that they can access the virtual machine via Azure Application Proxy. In the Azure portal, navigate to the Azure AD Application Proxy section and assign users or groups to the application.
  6. Test the Application: Once the setup is complete, it's important to test the application to ensure that it is working correctly. You can do this by accessing the application from a user's device and verifying that they are able to authenticate and access the virtual machine.

By following these steps, you can use Azure Application Proxy for authentication to a virtual machine in an on-premise setup. This will allow you to securely access the virtual machine from anywhere, while providing an additional layer of security for the on-premises resources.

It's important to note that Azure Application Proxy requires an Azure AD Premium P1 or P2 license. It is also important to have a good network bandwidth between the on-premises server and Azure to ensure good performance. Additionally, it's important to keep the connector updated to avoid security vulnerabilities.

In summary, Azure Application Proxy is a powerful tool that allows organizations to securely access on-premises web applications from anywhere, while providing an additional layer of security for the on-premises resources. By following the steps outlined in this blog post, you can configure Azure Application Proxy for authentication to a virtual machine in an on-premise setup, and enjoy the benefits of secure and seamless access to your virtual machines.

I hope this helps! Let me know if you have any questions.