Configure a VNet-to-VNet VPN gateway connection - Azure portal

This article helps you connect virtual networks (VNets) by using the VNet-to-VNet connection type using the Azure portal. The virtual networks can be in different regions and from different subscriptions. When you connect VNets from different subscriptions, the subscriptions don't need to be associated with the same tenant. This type of configuration creates a connection between two virtual network gateways. This article doesn't apply to VNet peering. For VNet peering, see the Virtual Network peering article.

You can create this configuration using various tools, depending on the deployment model of your VNet. The steps in this article apply to the Azure Resource Manager deployment model and the Azure portal. To switch to a different deployment model or deployment method article, use the dropdown.

About connecting VNets

The following sections describe the different ways to connect virtual networks.

VNet-to-VNet

Configuring a VNet-to-VNet connection is a simple way to connect VNets. When you connect a virtual network to another virtual network with a VNet-to-VNet connection type (VNet2VNet), it's similar to creating a Site-to-Site IPsec connection to an on-premises location. Both connection types use a VPN gateway to provide a secure tunnel with IPsec/IKE and function the same way when communicating. However, they differ in the way the local network gateway is configured.

When you create a VNet-to-VNet connection, the local network gateway address space is automatically created and populated. If you update the address space for one VNet, the other VNet automatically routes to the updated address space. It's typically faster and easier to create a VNet-to-VNet connection than a Site-to-Site connection. However, the local network gateway isn't visible in this configuration.

• If you know you want to specify more address spaces for the local network gateway, or plan to add more connections later and need to adjust the local network gateway, you should create the configuration using the Site-to-Site steps.
• The VNet-to-VNet connection doesn't include Point-to-Site client pool address space. If you need transitive routing for Point-to-Site clients, then create a Site-to-Site connection between the virtual network gateways, or use VNet peering.

Site-to-Site (IPsec)

If you're working with a complicated network configuration, you might prefer to connect your VNets by using a Site-to-Site connection instead. When you follow the Site-to-Site IPsec steps, you create and configure the local network gateways manually. The local network gateway for each VNet treats the other VNet as a local site. These steps allow you to specify more address spaces for the local network gateway to route traffic. If the address space for a VNet changes, you must manually update the corresponding local network gateway.

VNet peering

You can also connect your VNets by using VNet peering.

• VNet peering doesn't use a VPN gateway and has different constraints.
• VNet peering pricing is calculated differently than VNet-to-VNet VPN Gateway pricing.
• For more information about VNet peering, see the Virtual Network peering article.

Why create a VNet-to-VNet connection?

You might want to connect virtual networks by using a VNet-to-VNet connection for the following reasons:

Cross region geo-redundancy and geo-presence

• You can set up your own geo-replication or synchronization with secure connectivity without going over internet-facing endpoints.
• With Azure Traffic Manager and Azure Load Balancer, you can set up highly available workload with geo-redundancy across multiple Azure regions. For example, you can set up SQL Server Always On availability groups across multiple Azure regions.

Regional multi-tier applications with isolation or administrative boundaries

• Within the same region, you can set up multi-tier applications with multiple virtual networks that are connected together because of isolation or administrative requirements.

VNet-to-VNet communication can be combined with multi-site configurations. These configurations let you establish network topologies that combine cross-premises connectivity with inter-virtual network connectivity, as shown in the following diagram:

This article shows you how to connect VNets by using the VNet-to-VNet connection type. When you follow these steps as an exercise, you can use the following example settings values. In the example, the virtual networks are in the same subscription, but in different resource groups. If your VNets are in different subscriptions, you can't create the connection in the portal. Use PowerShell or CLI instead. For more information about VNet-to-VNet connections, see VNet-to-VNet FAQ.

Example settings

Values for VNet1:

• Virtual network settings

  • Name: VNet1
  • Address space: 10.1.0.0/16
  • Subscription: Select the subscription you want to use.
  • Resource group: TestRG1
  • Location: China East
  • Subnet
    • Name: FrontEnd
    • Address range: 10.1.0.0/24

• Virtual network gateway settings

  • Name: VNet1GW
  • Resource group: China East
  • Generation: Generation 2
  • Gateway type: Select VPN.
  • VPN type: Select Route-based.
  • SKU: VpnGw2
  • Generation: Generation2
  • Virtual network: VNet1
  • Gateway subnet address range: 10.1.255.0/27
  • Public IP address: Create new
  • Public IP address name: VNet1GWpip
  • Enable active-active mode: Disabled
  • Configure BGP: Disabled

• Connection

  • Name: VNet1toVNet4
  • Shared key: You can create the shared key yourself. When you create the connection between the VNets, the values must match. For this exercise, use abc123.

Values for VNet4:

• Virtual network settings

  • Name: VNet4
  • Address space: 10.41.0.0/16
  • Subscription: Select the subscription you want to use.
  • Resource group: TestRG4
  • Location: China North
  • Subnet
  • Name: FrontEnd
  • Address range: 10.41.0.0/24

• Virtual network gateway settings

  • Name: VNet4GW
  • Resource group: China North
  • Generation: Generation 2
  • Gateway type: Select VPN.
  • VPN type: Select Route-based.
  • SKU: VpnGw2
  • Generation: Generation2
  • Virtual network: VNet4
  • Gateway subnet address range: 10.41.255.0/27
  • Public IP address: Create new
  • Public IP address name: VNet4GWpip
  • Enable active-active mode: Disabled
  • Configure BGP: Disabled

• Connection

  • Name: VNet4toVNet1
  • Shared key: You can create the shared key yourself. When you create the connection between the VNets, the values must match. For this exercise, use abc123.

Create and configure VNet1

If you already have a VNet, verify that the settings are compatible with your VPN gateway design. Pay particular attention to any subnets that might overlap with other networks. Your connection won't work properly if you have overlapping subnets.

To create a virtual network

1. Sign in to the Azure portal.

2. In Search resources, service, and docs (G+/) at the top of the portal page, enter virtual network. Select Virtual network from the Marketplace search results to open the Virtual network page.

3. On the Virtual network page, select Create to open the Create virtual network page.

4. On the Basics tab, configure the virtual network settings for Project details and Instance details. You see a green check mark when the values you enter are validated. You can adjust the values shown in the example according to the settings that you require.

   

   • Subscription: Verify that the subscription listed is the correct one. You can change subscriptions by using the dropdown box.
   • Resource group: Select an existing resource group or select Create new to create a new one. For more information about resource groups, see Azure Resource Manager overview.
   • Name: Enter the name for your virtual network.
   • Region: Select the location for your virtual network. The location determines where the resources that you deploy to this virtual network will reside.

5. Select Next or Security to go to the Security tab. For this exercise, leave the default values for all the services on this page.

6. Select IP Addresses to go to the IP Addresses tab. On the IP Addresses tab, configure the settings.

   • IPv4 address space: By default, an address space is automatically created. You can select the address space and adjust it to reflect your own values. You can also add a different address space and remove the default that was automatically created. For example, you can specify the starting address as 10.1.0.0 and specify the address space size as /16. Then select Add to add that address space.

   • + Add subnet: If you use the default address space, a default subnet is created automatically. If you change the address space, add a new subnet within that address space. Select + Add subnet to open the Add subnet window. Configure the following settings, and then select Add at the bottom of the page to add the values.

     • Subnet name: An example is FrontEnd.
     • Subnet address range: The address range for this subnet. Examples are 10.1.0.0 and /24.

7. Review the IP addresses page and remove any address spaces or subnets that you don't need.

8. Select Review + create to validate the virtual network settings.

9. After the settings are validated, select Create to create the virtual network.

Create the VNet1 gateway

In this step, you create the virtual network gateway for your VNet. Creating a gateway can often take 45 minutes or more, depending on the selected gateway SKU. For gateway SKU pricing, see Pricing. If you're creating this configuration as an exercise, see the Example settings.

The virtual network gateway requires a specific subnet named GatewaySubnet. The gateway subnet is part of the IP address range for your virtual network and contains the IP addresses that the virtual network gateway resources and services use.

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. It's best to specify /27 or larger (/26, /25, etc.) for your gateway subnet.

To create a virtual network gateway

1. In Search resources, services, and docs (G+/), enter virtual network gateway. Locate Virtual network gateway in the Marketplace search results and select it to open the Create virtual network gateway page.

2. On the Basics tab, fill in the values for Project details and Instance details.

   

   • Subscription: Select the subscription you want to use from the dropdown list.

   • Resource group: This setting is autofilled when you select your virtual network on this page.

   • Name: Name your gateway. Naming your gateway isn't the same as naming a gateway subnet. It's the name of the gateway object you're creating.

   • Region: Select the region in which you want to create this resource. The region for the gateway must be the same as the virtual network.

   • Gateway type: Select VPN. VPN gateways use the virtual network gateway type VPN.

   • SKU: From the dropdown list, select the gateway SKU that supports the features you want to use. See Gateway SKUs. AZ SKUs support availability zones.

   • Generation: Select the generation you want to use. We recommend using a Generation2 SKU. For more information, see Gateway SKUs.

   • Virtual network: From the dropdown list, select the virtual network to which you want to add this gateway. If you can't see the virtual network for which you want to create a gateway, make sure you selected the correct subscription and region in the previous settings.

   • Gateway subnet address range or Subnet: The gateway subnet is required to create a VPN gateway.

     At this time, this field can show various different settings options, depending on the virtual network address space and whether you already created a subnet named GatewaySubnet for your virtual network.

     If you don't have a gateway subnet and you don't see the option to create one on this page, go back to your virtual network and create the gateway subnet. Then, return to this page and configure the VPN gateway.

3. Specify the values for Public IP address. These settings specify the public IP address object that gets associated to the VPN gateway. The public IP address is assigned to this object when the VPN gateway is created. The only time the primary 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.

   

   • Public IP address type: If you're presented with this option, select Standard. The Basic public IP address SKU is only supported for Basic SKU VPN gateways.
   • Public IP address: Leave Create new selected.
   • Public IP address name: In the text box, enter a name for your public IP address instance.
   • Public IP address SKU: Setting is autoselected.
   • Assignment: The assignment is typically autoselected. For the Standard SKU, assignment is always Static.
   • Enable active-active mode: For this exercise, you can select Disabled. However, you can choose to enable this setting if you're creating an active-active mode gateway configuration. For more information, see About active-active gateways. If you create an active-active gateway, you also must create an additional public IP address.
   • Configure BGP: Select Disabled, unless your configuration specifically requires this setting. If you do require this setting, the default ASN is 65515, although this value can be changed.

4. Select Review + create to run validation.

5. After validation passes, select Create to deploy the VPN gateway.

You can see the deployment status on the Overview page for your gateway. A gateway can take 45 minutes or more to fully create and deploy. After the gateway is created, you can view the IP address that has been assigned to it by looking at the virtual network in the portal. The gateway appears as a connected device.

Create and configure VNet4

After you've configured VNet1, create VNet4 and the VNet4 gateway by repeating the previous steps and replacing the values with VNet4 values. You don't need to wait until the virtual network gateway for VNet1 has finished creating before you configure VNet4. If you're using your own values, make sure the address spaces don't overlap with any of the VNets to which you want to connect.

Configure your connections

When the VPN gateways for both VNet1 and VNet4 have completed, you can create your virtual network gateway connections.

VNets in the same subscription can be connected using the portal, even if they are in different resource groups. However, if your VNets are in different subscriptions, you must use PowerShell to make the connections.

You can create either a bidirectional, or single direction connection. For this exercise, we'll specify a bidirectional connection. The bidirectional connection value creates two separate connections so that traffic can flow in both directions.

1. In the portal, go to VNet1GW.

2. On the virtual network gateway page, go to Connections. Select +Add.

   

3. On the Create connection page, fill in the connection values.

   

   • Connection type: Select VNet-to-VNet from the drop-down.
   • Establish bidirectional connectivity: Select this value
   • First connection name: VNet1-to-VNet4
   • Second connection name: VNet4-to-VNet1
   • Region: China North (the region for VNet1GW)

4. Click Next : Settings > at the bottom of the page to advance to the Settings page.

5. On the Settings page, specify the following values:

   • First virtual network gateway: Select VNet1GW from the dropdown.
   • Second virtual network gateway: Select VNet4GW from the dropdown.
   • Shared key (PSK): In this field, enter a shared key for your connection. You can generate or create this key yourself. In a site-to-site connection, the key you use is the same for your on-premises device and your virtual network gateway connection. The concept is similar here, except that rather than connecting to a VPN device, you're connecting to another virtual network gateway. The important thing when specifying a shared key is that it's exactly the same for both sides of the connection.
   • IKE Protocol: IKEv2

6. For this exercise, you can leave the rest of the settings as their default values.

7. Select Review + create, then Create to validate and create your connections.

Verify your connections

1. Locate the virtual network gateway in the Azure portal. For example, VNet1GW

2. On the Virtual network gateway page, select Connections to view the Connections page for the virtual network gateway. After the connection is established, you'll see the Status values change to Connected.

   

3. Under the Name column, select one of the connections to view more information. When data begins flowing, you'll see values for Data in and Data out.

   

Add more connections

If you want to add more connections, navigate to the virtual network gateway from which you want to create the connection, then select Connections. You can create another VNet-to-VNet connection, or create an IPsec Site-to-Site connection to an on-premises location. Be sure to adjust the Connection type to match the type of connection you want to create. When you configure a connection that uses a shared key, make sure that the shared key is exactly the same for both sides of the connection. Before you create more connections, verify that the address space for your virtual network doesn't overlap with any of the address spaces you want to connect to. For steps to create a Site-to-Site connection, see Create a Site-to-Site connection.

VNet-to-VNet FAQ

See the VPN Gateway FAQ for VNet-to-VNet frequently asked questions.

Next steps

• For information about how you can limit network traffic to resources in a virtual network, see Network Security.

• For information about how Azure routes traffic between Azure, on-premises, and Internet resources, see Virtual network traffic routing.