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Create a virtual network with a site-to-site VPN connection using CLI

  • Article

This article shows you how to use the Azure CLI to create a site-to-site VPN gateway connection from your on-premises network to the VNet. The steps in this article apply to the Resource Manager deployment model. You can also create this configuration using a different deployment tool or deployment model by selecting a different option from the following list:

Site-to-site VPN Gateway cross-premises connection diagram for CLI article.

A site-to-site VPN gateway connection is used to connect your on-premises network to an Azure virtual network over an IPsec/IKE (IKEv1 or IKEv2) VPN tunnel. This type of connection requires a VPN device located on-premises that has an externally facing public IP address assigned to it. For more information about VPN gateways, see About VPN gateway.

Before you begin

Verify that you have met the following criteria before beginning configuration:

  • Make sure you have a compatible VPN device and someone who is able to configure it. For more information about compatible VPN devices and device configuration, see About VPN Devices.
  • Verify that you have an externally facing public IPv4 address for your VPN device.
  • If you're unfamiliar with the IP address ranges located in your on-premises network configuration, you need to coordinate with someone who can provide those details for you. When you create this configuration, you must specify the IP address range prefixes that Azure will route to your on-premises location. None of the subnets of your on-premises network can over lap with the virtual network subnets that you want to connect to.
  • This article requires version 2.0 or later of the Azure CLI. If using Azure Cloud Shell, the latest version is already installed.

Example values

You can use the following values to create a test environment, or refer to these values to better understand the examples in this article:

#Example values

VnetName                = VNet1 
ResourceGroup           = TestRG1 
Location                = eastus 
AddressSpace            = 10.1.0.0/16 
SubnetName              = Frontend
Subnet                  = 10.1.0.0/24 
GatewaySubnet           = 10.1.255.0/27 
LocalNetworkGatewayName = Site1
LNG Public IP           = <On-premises VPN device IP address>
LocalAddrPrefix1        = 10.0.0.0/24
LocalAddrPrefix2        = 20.0.0.0/24   
GatewayName             = VNet1GW 
PublicIP                = VNet1GWIP 
GatewayType             = Vpn 
ConnectionName          = VNet1toSite2

1. Connect to your subscription

If you choose to run CLI locally, connect to your subscription. If you're using Azure Cloud Shell in the browser, you don't need to connect to your subscription. You'll connect automatically in Azure Cloud Shell. However, you may want to verify that you're using the correct subscription after you connect.

Sign in to your Azure subscription with the az login command and follow the on-screen directions. For more information about signing in, see Get Started with Azure CLI.

az login

If you have more than one Azure subscription, list the subscriptions for the account.

az account list --all

Specify the subscription that you want to use.

az account set --subscription <replace_with_your_subscription_id>

2. Create a resource group

The following example creates a resource group named 'TestRG1' in the 'eastus' location. If you already have a resource group in the region that you want to create your VNet, you can use that one instead.

az group create --name TestRG --location eastus

3. Create a virtual network

If you don't already have a virtual network, create one using the az network vnet create command. When creating a virtual network, make sure that the address spaces you specify don't overlap any of the address spaces that you have on your on-premises network.

Note

In order for this VNet to connect to an on-premises location, you need to coordinate with your on-premises network administrator to carve out an IP address range that you can use specifically for this virtual network. If a duplicate address range exists on both sides of the VPN connection, traffic does not route the way you may expect it to. Additionally, if you want to connect this VNet to another VNet, the address space cannot overlap with other VNet. Take care to plan your network configuration accordingly.

The following example creates a virtual network named 'VNet1' and a subnet, 'Subnet1'.

az network vnet create --name VNet1 --resource-group TestRG1 --address-prefix 10.1.0.0/16 --location eastus --subnet-name Subnet1 --subnet-prefix 10.1.0.0/24

4. Create the gateway subnet

The virtual network gateway uses specific subnet called the gateway subnet. The gateway subnet is part of the virtual network IP address range that you specify when configuring your virtual network. It contains the IP addresses that the virtual network gateway resources and services use. The subnet must be named 'GatewaySubnet' in order for Azure to deploy the gateway resources. You can't specify a different subnet to deploy the gateway resources to. If you don't have a subnet named 'GatewaySubnet', when you create your VPN gateway, it will fail.

When you create the gateway subnet, you specify the number of IP addresses that the subnet contains. The number of IP addresses needed depends on the VPN gateway configuration that you want to create. Some configurations require more IP addresses than others. We recommend that you create a gateway subnet that uses a /27 or /28.

If you see an error that specifies that the address space overlaps with a subnet, or that the subnet is not contained within the address space for your virtual network, check your VNet address range. You may not have enough IP addresses available in the address range you created for your virtual network. For example, if your default subnet encompasses the entire address range, there are no IP addresses left to create additional subnets. You can either adjust your subnets within the existing address space to free up IP addresses, or specify an additional address range and create the gateway subnet there.

Use the az network vnet subnet create command to create the gateway subnet.

az network vnet subnet create --address-prefix 10.1.255.0/27 --name GatewaySubnet --resource-group TestRG1 --vnet-name VNet1

Important

Network security groups (NSGs) on the gateway subnet are not supported. Associating a network security group to this subnet might cause your virtual network gateway (VPN and ExpressRoute gateways) to stop functioning as expected. For more information about network security groups, see What is a network security group?

5. Create the local network gateway

The local network gateway typically refers to your on-premises location. You give the site a name by which Azure can refer to it, then specify the IP address of the on-premises VPN device to which you will create a connection. You also specify the IP address prefixes that will be routed through the VPN gateway to the VPN device. The address prefixes you specify are the prefixes located on your on-premises network. If your on-premises network changes, you can easily update the prefixes.

Use the following values:

  • The --gateway-ip-address is the IP address of your on-premises VPN device.
  • The --local-address-prefixes are your on-premises address spaces.

Use the az network local-gateway create command to add a local network gateway with multiple address prefixes:

az network local-gateway create --gateway-ip-address 23.99.221.164 --name Site2 --resource-group TestRG1 --local-address-prefixes 10.0.0.0/24 20.0.0.0/24

6. Request a public IP address

A VPN gateway must have a public IP address. You first request the IP address resource, and then refer to it when creating your virtual network gateway. The IP address is dynamically assigned to the resource when the VPN gateway is created. The only time the public IP address changes is when the gateway is deleted and re-created. It doesn't change across resizing, resetting, or other internal maintenance/upgrades of your VPN gateway. Note that if you want to create a VPN Gateway using the Basic gateway SKU, request a public IP address with the following values --allocation-method Dynamic --sku Basic.

Use the az network public-ip create command to request a public IP address.

az network public-ip create --name VNet1GWIP --resource-group TestRG1 --allocation-method Static --sku Standard

7. Create the VPN gateway

Create the virtual network VPN gateway. Creating a gateway can often take 45 minutes or more, depending on the selected gateway SKU.

Use the following values:

  • The --gateway-type for a site-to-site configuration is Vpn. The gateway type is always specific to the configuration that you're implementing. For more information, see Gateway types.
  • The --vpn-type is RouteBased (referred to as a Dynamic Gateway in some documentation).
  • Select the Gateway SKU that you want to use. There are configuration limitations for certain SKUs. For more information, see Gateway SKUs.

Create the VPN gateway using the az network vnet-gateway create command. If you run this command using the '--no-wait' parameter, you don't see any feedback or output. This parameter allows the gateway to create in the background. It takes 45 minutes or more to create a gateway.

az network vnet-gateway create --name VNet1GW --public-ip-address VNet1GWIP --resource-group TestRG1 --vnet VNet1 --gateway-type Vpn --vpn-type RouteBased --sku VpnGw1 --no-wait 

8. Configure your VPN device

Site-to-site connections to an on-premises network require a VPN device. In this step, you configure your VPN device. When configuring your VPN device, you need the following:

  • A shared key. This is the same shared key that you specify when creating your site-to-site VPN connection. In our examples, we use a basic shared key. We recommend that you generate a more complex key to use.

  • The public IP address of your virtual network gateway. You can view the public IP address by using the Azure portal, PowerShell, or CLI. To find the public IP address of your virtual network gateway, use the az network public-ip list command. For easy reading, the output is formatted to display the list of public IPs in table format.

    az network public-ip list --resource-group TestRG1 --output table

Depending on the VPN device that you have, you might be able to download a VPN device configuration script. For more information, see Download VPN device configuration scripts.

The following links provide more configuration information:

9. Create the VPN connection

Create the site-to-site VPN connection between your virtual network gateway and your on-premises VPN device. Pay particular attention to the shared key value, which must match the configured shared key value for your VPN device.

Create the connection using the az network vpn-connection create command.

az network vpn-connection create --name VNet1toSite2 --resource-group TestRG1 --vnet-gateway1 VNet1GW -l eastus --shared-key abc123 --local-gateway2 Site2

After a short while, the connection will be established.

10. Verify the VPN connection

You can verify that your connection succeeded by using the az network vpn-connection show command. In the example, '--name' refers to the name of the connection that you want to test. When the connection is in the process of being established, its connection status shows 'Connecting'. Once the connection is established, the status changes to 'Connected'. Modify the following example with the values for your environment.

az network vpn-connection show --name <connection-name> --resource-group <resource-group-name>

If you want to use another method to verify your connection, see Verify a VPN Gateway connection.

To connect to a virtual machine

You can connect to a VM that's deployed to your virtual network by creating a Remote Desktop Connection to your VM. The best way to initially verify that you can connect to your VM is to connect by using its private IP address, rather than computer name. That way, you're testing to see if you can connect, not whether name resolution is configured properly.

  1. Locate the private IP address. You can find the private IP address of a VM by either looking at the properties for the VM in the Azure portal or by using PowerShell.

    • Azure portal: Locate your VM in the Azure portal. View the properties for the VM. The private IP address is listed.

    • PowerShell: Use the example to view a list of VMs and private IP addresses from your resource groups. You don't need to modify this example before using it.

      $VMs = Get-AzVM
$Nics = Get-AzNetworkInterface | Where-Object VirtualMachine -ne $null

foreach ($Nic in $Nics) {
$VM = $VMs | Where-Object -Property Id -eq $Nic.VirtualMachine.Id
$Prv = $Nic.IpConfigurations | Select-Object -ExpandProperty PrivateIpAddress
$Alloc = $Nic.IpConfigurations | Select-Object -ExpandProperty PrivateIpAllocationMethod
Write-Output "$($VM.Name): $Prv,$Alloc"
}

  2. Verify that you're connected to your virtual network.

  3. Open Remote Desktop Connection by entering RDP or Remote Desktop Connection in the search box on the taskbar. Then select Remote Desktop Connection. You can also open Remote Desktop Connection by using the mstsc command in PowerShell.

  4. In Remote Desktop Connection, enter the private IP address of the VM. You can select Show Options to adjust other settings and then connect.

If you're having trouble connecting to a VM over your VPN connection, check the following points:

  • Verify that your VPN connection is successful.
  • Verify that you're connecting to the private IP address for the VM.
  • If you can connect to the VM by using the private IP address but not the computer name, verify that you've configured DNS properly. For more information about how name resolution works for VMs, see Name resolution for VMs.

For more information about RDP connections, see Troubleshoot Remote Desktop connections to a VM.

Common tasks

This section contains common commands that are helpful when working with site-to-site configurations. For the full list of CLI networking commands, see Azure CLI - Networking.

To view local network gateways

To view a list of the local network gateways, use the az network local-gateway list command.

az network local-gateway list --resource-group TestRG1

To modify local network gateway IP address prefixes - no gateway connection

If you don't have a gateway connection and you want to add or remove IP address prefixes, you use the same command that you use to create the local network gateway, az network local-gateway create. You can also use this command to update the gateway IP address for the VPN device. To overwrite the current settings, use the existing name of your local network gateway. If you use a different name, you create a new local network gateway, instead of overwriting the existing one.

Each time you make a change, the entire list of prefixes must be specified, not just the prefixes that you want to change. Specify only the prefixes that you want to keep. In this case, 10.0.0.0/24 and 20.0.0.0/24

az network local-gateway create --gateway-ip-address 23.99.221.164 --name Site2 -g TestRG1 --local-address-prefixes 10.0.0.0/24 20.0.0.0/24

To modify local network gateway IP address prefixes - existing gateway connection

If you have a gateway connection and want to add or remove IP address prefixes, you can update the prefixes using az network local-gateway update. This results in some downtime for your VPN connection. When modifying the IP address prefixes, you don't need to delete the VPN gateway.

Each time you make a change, the entire list of prefixes must be specified, not just the prefixes that you want to change. In this example, 10.0.0.0/24 and 20.0.0.0/24 are already present. We add the prefixes 30.0.0.0/24 and 40.0.0.0/24 and specify all 4 of the prefixes when updating.

az network local-gateway update --local-address-prefixes 10.0.0.0/24 20.0.0.0/24 30.0.0.0/24 40.0.0.0/24 --name VNet1toSite2 -g TestRG1

To modify the local network gateway 'gatewayIpAddress'

If the VPN device that you want to connect to has changed its public IP address, you need to modify the local network gateway to reflect that change. The gateway IP address can be changed without removing an existing VPN gateway connection (if you have one). To modify the gateway IP address, replace the values 'Site2' and 'TestRG1' with your own using the az network local-gateway update command.

az network local-gateway update --gateway-ip-address 23.99.222.170 --name Site2 --resource-group TestRG1

Verify that the IP address is correct in the output:

"gatewayIpAddress": "23.99.222.170",

To verify the shared key values

Verify that the shared key value is the same value that you used for your VPN device configuration. If it is not, either run the connection again using the value from the device, or update the device with the value from the return. The values must match. To view the shared key, use the az network vpn-connection-list.

az network vpn-connection shared-key show --connection-name VNet1toSite2 --resource-group TestRG1

To view the VPN gateway Public IP address

To find the public IP address of your virtual network gateway, use the az network public-ip list command. For easy reading, the output for this example is formatted to display the list of public IPs in table format.

az network public-ip list --resource-group TestRG1 --output table

Next steps