# Access Azure Windows VMs privately using Tailscale

Last validated Jan 5, 2026

Microsoft Azure is a cloud service provider offering Linux and Windows virtual machines, to which Tailscale can be used to provide secure connectivity. This topic covers Windows VMs running within Azure. For Linux VMs, refer to [Access Azure Linux VMs privately using Tailscale][kb-azure-linux].

## Prerequisites

Before you begin this guide, you'll need a Tailscale network set up and
configured with at least one existing device. Read our [getting started guide][kb-install]
if you need help with this.

## Step 1: Set up the Tailscale client for Windows VMs

First, [create a Virtual Machine][xt-azure-vms]
running Windows Datacenter Edition.

If at least one side of a tunnel has "easy NAT," where Tailscale can determine the UDP port
number on the far side of the NAT device, then it will make
[direct connections to minimize latency.][bl-how-tailscale-works]
We ensure that the Azure nodes can make direct connections by allowing UDP port 41641 to
ingress through the firewall.

In the Networking step while creating the VM choose Advanced for the NIC network security group,
and create a network security policy to allow UDP port 41641 to ingress.

![Network Security Group allow port 41641](install/cloud/azure/windows/windows-nsg.jpg)

For the initial setup it is helpful to also allow RDP and/or SSH. Once Tailscale is installed, public
access can be removed in favor of going through Tailscale.

Then RDP to the system, and [download the latest Windows installer][co-download-windows].

It is possible to log in using a browser as described in
[install Tailscale on Windows][kb-install-windows], as Windows
Datacenter Edition does include a GUI and web browser.

 However this tends not to work as well
for a Cloud VM where one is likely not already logged in from the browser.

Alternately, one can use a `cmd.exe` shell to run the Tailscale CLI command and [use an auth key][kb-auth-keys]:
`tailscale up --accept-dns=false --auth-key=tskey-0123456789abcdef`

> **Note:**
>
> For Azure VMs it is generally best to let Azure handle the DNS configuration,
> not have Tailscale override it, so we added `--accept-dns=false`.

## Step 2: Advertise routes from the VM

For the benefit of the *other* nodes in the tailnet we'll set up
[split DNS][kb-dns-using-settings] to allow
use of the same DNS names as are used inside of Azure. The
[Azure DNS server address is 168.63.129.16][xt-azure-name-resolution], which is an anycast address that will go
to the nearest DNS server within Azure.

We'll use `cmd.exe` to have our VM advertise routes for both the subnet it sits on as well as the
Azure DNS server. For example, if the subnet address range is 10.1.0.0/24, the command would be:

```shell
tailscale set --advertise-routes=10.1.0.0/24,168.63.129.16/32 --accept-dns=false
```

## Step 3: Add Azure DNS for your tailnet

In the [DNS](https://login.tailscale.com/admin/dns) page of the admin console we add a nameserver
restricted to the `internal.cloudapp.net` domain, pointing to the Azure DNS server which we
made available through our VM.

![Adding a Split DNS resolver for internal.cloudapp.net](install/cloud/azure/windows/azure-add-DNS.jpg)

Now the same hostnames which work between nodes running within Azure will also be available
to all nodes on our tailnet.

## Step 4: Remove public SSH access

As we can now SSH to the system over the private Tailscale network, there is no reason to leave
the SSH port open on a public IP address. In the Settings > Network tab select the ingress
rule for "SSH" and delete it.

![Disable public SSH port.](install/cloud/azure/windows/azure-disable-ssh.jpg)

## 4via6 subnet routers

If your network has subnets with overlapping IPv4 addresses, you can use the [4via6 subnet routers][kb-4via6-subnets]
feature to ensure traffic from each node in your tailnet is routed to the correct device.

[bl-how-tailscale-works]: /blog/how-tailscale-works

[co-download-windows]: /download/windows

[kb-4via6-subnets]: /docs/features/subnet-routers/4via6-subnets

[kb-auth-keys]: /docs/features/access-control/auth-keys

[kb-azure-linux]: /docs/install/cloud/azure/linux

[kb-dns-using-settings]: /docs/reference/dns-in-tailscale#tailscale-dns-settings

[kb-install-windows]: /docs/install/windows

[kb-install]: /docs/how-to/quickstart

[xt-azure-name-resolution]: https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-name-resolution-for-vms-and-role-instances#azure-provided-name-resolution

[xt-azure-vms]: https://portal.azure.com/#blade/HubsExtension/BrowseResource/resourceType/Microsoft.Compute%2FVirtualMachines