VNet to VNet connectivity with Fortigate

This article describes how to create a connection between two virtual networks in the same environment. When you set up the connections, you learn how VPN gateways in Azure Stack Hub work. Connect two VNETs within the same Azure Stack Hub environment using Fortinet FortiGate. This procedure deploys two VNETs with a FortiGate NVA, a network virtual appliance, in each VNET each within a separate resource group. It also details the changes required to set up an IPSec VPN between the two VNETs. Repeat the steps in this article for each VNET deployment.

Prerequisites

  • Access to a system with available capacity to deploy the required compute, network, and resource requirements needed for this solution.

  • A network virtual appliance (NVA) solution downloaded and published to the Azure Stack Hub Marketplace. An NVA controls the flow of network traffic from a perimeter network to other networks or subnets. This procedure uses the Fortinet FortiGate Next-Generation Firewall Single VM Solution.

  • At least two available FortiGate license files to activate the FortiGate NVA. Information on how to get these licenses, see the Fortinet Document Library article Registering and downloading your license.

    This procedure uses the Single FortiGate-VM deployment. You can find steps on how to connect the FortiGate NVA to the Azure Stack Hub VNET to in your on-premises network.

    For more information on how to deploy the FortiGate solution in an active-passive (HA) set up, see the details in the Fortinet Document Library article HA for FortiGate-VM on Azure.

Deployment parameters

The following table summarizes the parameters that are used in these deployments for reference:

Deployment one: Forti1

FortiGate Instance Name Forti1
BYOL License/Version 6.0.3
FortiGate administrative username fortiadmin
Resource Group name forti1-rg1
Virtual network name forti1vnet1
VNET Address Space 172.16.0.0/16*
Public VNET subnet name forti1-PublicFacingSubnet
Public VNET address prefix 172.16.0.0/24*
Inside VNET subnet name forti1-InsideSubnet
Inside VNET subnet prefix 172.16.1.0/24*
VM Size of FortiGate NVA Standard F2s_v2
Public IP address name forti1-publicip1
Public IP address type Static

Deployment two: Forti2

FortiGate Instance Name Forti2
BYOL License/Version 6.0.3
FortiGate administrative username fortiadmin
Resource Group name forti2-rg1
Virtual network name forti2vnet1
VNET Address Space 172.17.0.0/16*
Public VNET subnet name forti2-PublicFacingSubnet
Public VNET address prefix 172.17.0.0/24*
Inside VNET subnet name Forti2-InsideSubnet
Inside VNET subnet prefix 172.17.1.0/24*
VM Size of FortiGate NVA Standard F2s_v2
Public IP address name Forti2-publicip1
Public IP address type Static

Note

* Choose a different set of address spaces and subnet prefixes if the above overlap in any way with the on-premises network environment including the VIP Pool of either Azure Stack Hub. Also ensure that the address ranges do not overlap with one another.

Deploy the FortiGate NGFW

  1. Open the Azure Stack Hub user portal.

  2. Select Create a resource and search for FortiGate.

    The search results list shows FortiGate NGFW - Single VM Deployment.

  3. Select the FortiGate NGFW and select Create.

  4. Complete the Basics using the parameters from the Deployment parameters table.

    The Basics screen has values from the deployment parameters selected and entered in list and text boxes.

  5. Select OK.

  6. Provide the Virtual network, Subnets, and VM Size details using the Deployment parameters table.

    Warning

    If the on-premises network overlaps with the IP range 172.16.0.0/16, you must select and set up a different network range and subnets. If you wish to use different names and ranges than the ones in the Deployment parameters table, use parameters that will not conflict with the on-premises network. Take care when setting the VNET IP range and subnet ranges within the VNET. You do not want the range to overlap with the IP ranges that exist in your on-premises network.

  7. Select OK.

  8. Configure the Public IP for the Fortigate NVA:

    The IP Assignment dialog box shows the value forti1-publicip1 for "Public IP address name" and Static for "Public IP Address Type".

  9. Select OK. And then select OK.

  10. Select Create.

The deployment will take about 10 minutes.

Configure routes (UDRs) for each VNET

Perform these steps for both deployments, forti1-rg1 and forti2-rg1.

  1. Open the Azure Stack Hub user portal.

  2. Select Resource groups. Type forti1-rg1 in the filter and double-click the forti1-rg1 resource group.

    Ten resources are listed for the forti1-rg1 resource group.

  3. Select the forti1-forti1-InsideSubnet-routes-xxxx resource.

  4. Select Routes under Settings.

    The Routes button is selected in the Settings dialog box.

  5. Delete the to-Internet Route.

    The to-Internet Route is the only route listed, and it is selected. There is a delete button.

  6. Select Yes.

  7. Select Add to add a new route.

  8. Name the route to-onprem.

  9. Enter the IP network range that defines the network range of the on-premises network to which the VPN will connect.

  10. Select Virtual appliance for Next hop type and 172.16.1.4. Use your IP range if you are using a different IP range.

    The Add route dialog box shows the four values that have been selected and entered in the text boxes.

  11. Select Save.

You will need a valid license file from Fortinet to activate each FortiGate NVA. The NVAs will not function until you have activated each NVA. For more information how to get a license file and steps to activate the NVA, see the Fortinet Document Library article Registering and downloading your license.

Two license files will need to be acquired - one for each NVA.

Create an IPSec VPN between the two NVAs

Once the NVAs have been activated, follow these steps to create an IPSec VPN between the two NVAs.

Following the below steps for both the forti1 NVA and forti2 NVA:

  1. Get the assigned Public IP address by navigating to the fortiX VM overview page:

    The forti1 virtual machine Overview page show values for forti1, such as the "Resource group" and Status.

  2. Copy the assigned IP address, open a browser, and paste the address into the address bar. Your browser may warn you that the security certificate is not trusted. Continue anyway.

  3. Enter the FortiGate administrative user name and password you provided during the deployment.

    The login dialog box has user and password text boxes, and a Login button.

  4. Select System > Firmware.

  5. Select the box showing the latest firmware, for example, FortiOS v6.2.0 build0866.

    The Firmware dialog box has the firmware identifier "FortiOS v6.2.0 build0866", a link to release notes, and two buttons: "Backup config and upgrade", and Upgrade.

  6. Select Backup config and upgrade > Continue.

  7. The NVA updates its firmware to the latest build and reboots. The process takes about five minutes. Log back into the FortiGate web console.

  8. Click VPN > IPSec Wizard.

  9. Enter a name for the VPN, for example, conn1 in the VPN Creation Wizard.

  10. Select This site is behind NAT.

    The screenshot of the VPN Creation Wizard shows it to be on the first step, VPN Setup. The following values are selected: "Site to Site" for Template Type, "FortiGate" for Remote Device Type, and "This site is behind NAT" for NAT Configuration.

  11. Select Next.

  12. Enter the remote IP address of the on-premises VPN device to which you are going to connect.

  13. Select port1 as the Outgoing Interface.

  14. Select Pre-shared Key and enter (and record) a pre-shared key.

    Note

    You will need this key to set up the connection on the on-premises VPN device, that is, they must match exactly.

    The screenshot of the VPN Creation Wizard shows it to be on the second step, Authentication, and the selected values are highlighted.

  15. Select Next.

  16. Select port2 for the Local Interface.

  17. Enter the local subnet range:

    • forti1: 172.16.0.0/16
    • forti2: 172.17.0.0/16

    Use your IP range if you are using a different IP range.

  18. Enter the appropriate Remote Subnet(s) that represent the on-premises network, which you will connect to through the on-premises VPN device.

    • forti1: 172.16.0.0/16
    • forti2: 172.17.0.0/16

    Use your IP range if you are using a different IP range.

    The screenshot of the VPN Creation Wizard shows it to be on the third step, Policy & Routing. It shows the selected and entered values.

  19. Select Create

  20. Select Network > Interfaces.

    The interface list shows two interfaces: port1, which has been configured, and port2, which hasn't. There are buttons to create, edit, and delete interfaces.

  21. Double-click port2.

  22. Choose LAN in the Role list and DHCP for the Addressing mode.

  23. Select OK.

Repeat the steps for the other NVA.

Bring Up All Phase 2 Selectors

Once the above has been completed for both NVAs:

  1. On the forti2 FortiGate web console, select to Monitor > IPsec Monitor.

    The monitor for VPN connection conn1 is listed. It is shown as being down, as is the corresponding Phase 2 Selector.

  2. Highlight conn1 and select the Bring Up > All Phase 2 Selectors.

    The monitor and Phase 2 Selector are both shown as up.

Test and validate connectivity

You should now be able to route in between each VNET via the FortiGate NVAs. To validate the connection, create an Azure Stack Hub VM in each VNET's InsideSubnet. Creating an Azure Stack Hub VM can be done via the portal, Azure CLI, or PowerShell. When creating the VMs:

  • The Azure Stack Hub VMs are placed on the InsideSubnet of each VNET.

  • You don't apply any NSGs to the VM upon creation (That is, remove the NSG that gets added by default if you create the VM from the portal.

  • Ensure that the VMS firewall rules allow the communication you are going to use to test connectivity. For testing purposes, it is recommended to disable the firewall completely within the OS if at all possible.

Next steps

Differences and considerations for Azure Stack Hub networking
Offer a network solution in Azure Stack Hub with Fortinet FortiGate