What is Azure Bastion?
The Azure Bastion service is a new fully platform-managed PaaS service that you provision inside your virtual network. It provides secure and seamless RDP/SSH connectivity to your virtual machines directly in the Azure portal over SSL. When you connect via Azure Bastion, your virtual machines do not need a public IP address.
Bastion provides secure RDP and SSH connectivity to all VMs in the virtual network in which it is provisioned. Using Azure Bastion protects your virtual machines from exposing RDP/SSH ports to the outside world while still providing secure access using RDP/SSH. With Azure Bastion, you connect to the virtual machine directly from the Azure portal. You don't need an additional client, agent, or piece of software.
Azure Bastion is deployed in your virtual network and, once deployed, it provides the secure RDP/SSH experience for all the virtual machines in your virtual network. Once you provision an Azure Bastion service in your virtual network, the RDP/SSH experience is available to all your VMs in the same virtual network. The deployment is per virtual network, not per subscription/account or virtual machine.
RDP and SSH are some of the fundamental means through which you can connect to your workloads running in Azure. Exposing RDP/SSH ports over the Internet isn't desired and is seen as a significant threat surface. This is often due to protocol vulnerabilities. To contain this threat surface, you can deploy bastion hosts (also known as jump-servers) at the public side of your perimeter network. Bastion host servers are designed and configured to withstand attacks. Bastion servers also provide RDP and SSH connectivity to the workloads sitting behind the bastion, as well as further inside the network.
This figure shows the architecture of an Azure Bastion deployment. In this diagram:
- The Bastion host is deployed in the virtual network.
- The user connects to the Azure portal using any HTML5 browser.
- The user selects the virtual machine to connect to.
- With a single click, the RDP/SSH session opens in the browser.
- No public IP is required on the Azure VM.
The following features are available:
- RDP and SSH directly in Azure portal: You can directly get to the RDP and SSH session directly in the Azure portal using a single click seamless experience.
- Remote Session over SSL and firewall traversal for RDP/SSH: Azure Bastion uses an HTML5 based web client that is automatically streamed to your local device, so that you get your RDP/SSH session over SSL on port 443 enabling you to traverse corporate firewalls securely.
- No Public IP required on the Azure VM: Azure Bastion opens the RDP/SSH connection to your Azure virtual machine using private IP on your VM. You don't need a public IP on your virtual machine.
- No hassle of managing NSGs: Azure Bastion is a fully managed platform PaaS service from Azure that is hardened internally to provide you secure RDP/SSH connectivity. You don't need to apply any NSGs on Azure Bastion subnet. Because Azure Bastion connects to your virtual machines over private IP, you can configure your NSGs to allow RDP/SSH from Azure Bastion only. This removes the hassle of managing NSGs each time you need to securely connect to your virtual machines.
- Protection against port scanning: Because you do not need to expose your virtual machines to public Internet, your VMs are protected against port scanning by rogue and malicious users located outside your virtual network.
- Protect against zero-day exploits. Hardening in one place only: Azure Bastion is a fully platform-managed PaaS service. Because it sits at the perimeter of your virtual network, you don’t need to worry about hardening each of the virtual machines in your virtual network. The Azure platform protects against zero-day exploits by keeping the Azure Bastion hardened and always up-to-date for you.
Which regions are available?
We are working hard to add additional regions. When a region is added, we will add it to this list.
- West US
- East US
- West Europe
- South Central US
- Australia East
- Japan East
Do I need a public IP on my virtual machine?
You do NOT need a public IP on the Azure Virtual Machine that you are connecting to with the Azure Bastion service. The Bastion service will open the RDP/SSH session/connection to your virtual machine over the private IP of your virtual machine, within your virtual network.
Do I need an RDP or SSH client?
You do not need an RDP or SSH client to access the RDP/SSH to your Azure virtual machine in your Azure portal. Use the Azure portal to let you get RDP/SSH access to your virtual machine directly in the browser.
Do I need an agent running in the Azure virtual machine?
You don't need to install an agent or any software on your browser or on your Azure virtual machine. The Bastion service is agentless and does not require any additional software for RDP/SSH.
Which browsers are supported?
Use the Microsoft Edge browser or Google Chrome on Windows. For Apple Mac, use Google Chrome browser. Microsoft Edge Chromium is also supported on both Windows and Mac, respectively.
Are any roles required to access a virtual machine?
In order to make a connection, the following roles are required:
- Reader role on the virtual machine
- Reader role on the NIC with private IP of the virtual machine
- Reader role on the Azure Bastion resource
What is the pricing?
For more information, see the pricing page.
Why do I get "Your session has expired" error message before the Bastion session starts?
A session should be initiated only from the Azure portal. Sign in to the Azure portal and begin your session again. If you go to the URL directly from another browser session or tab, this error is expected. It helps ensure that your session is more secure and that the session can be accessed only through the Azure portal.
What keyboard layouts are supported during the Bastion remote session?
Azure Bastion currently supports en-us-qwerty keyboard layout inside the VM. Support for other locales for keyboard layout is work in progress.
Is user-defined routing (UDR) supported on an Azure Bastion subnet?
No. UDR is not supported on an Azure Bastion subnet. For scenarios that include both Azure Bastion and Azure Firewall/Network Virtual Appliance (NVA) in the same virtual network, you don’t need to force traffic from an Azure Bastion subnet to Azure Firewall because the communication between Azure Bastion and your VMs is private. For more details, see Accessing VMs behind Azure Firewall with Bastion.
Is file-transfer supported with Azure Bastion RDP session?
We are working hard to add new features. As of now, file transfer is not supported but is part of our roadmap. Please feel free to share your feedback about new features on the Azure Bastion Feedback page.