Google Cloud VPN

This tutorial provides information and examples of how to configure IPsec VPN between Cloudflare Magic WAN with a GCP Cloud VPN.

Prerequisites

You need to have a GCP VPN gateway created in your GCP account. This is needed to route traffic between your GCP virtual private cloud (VPC) and Cloudflare Magic WAN. Refer to the GCP documentation to learn more about creating a Cloud VPN gateway.

A Classic VPN Gateway is required to support static routing. Route tables will also need to be manually configured to allow the routing between the VPN and Cloudflare Magic WAN to work. Refer to GCP routing options to learn more about GCP VPC routing.

Google Cloud Platform

Create a GCP Cloud VPN Gateway

1. Go to Network Connectivity > VPN.
2. Select the Cloud VPN Gateways tab > Create VPN Gateway.
3. Give your gateway a descriptive name.
4. Choose the network you want to connect to with this Cloud VPN Gateway (VPC).
5. Select a region where this Cloud VPN Gateway should be located.
6. Choose IPv4 as the IP traffic type that will flow through this Gateway.

Note

Cloudflare Magic WAN does not yet support private routing via IPv6.

Configure the VPN connection

1. Go to Network Connectivity > VPN.
2. Select the Cloud VPN Tunnels tab > Create VPN Tunnel.
3. Select the VPN Gateway you have created > Continue.
4. Give your tunnel a descriptive name.
5. For Remote Peer IP Address, use one of the public anycast Magic WAN IPs given to you by your account team.
6. In IKE version, select IKEv2.
7. You can generate an IKE pre-shared key, or add one you already own. If you generate one during this set up, keep it somewhere safe since you will need it in other steps to finish setting up Magic WAN and GCP.
8. Choose Route-based as routing option.
9. In Remote network IP range define the network you are going to expose to GCP via Cloudflare Magic WAN.

Note

You can add new IP ranges once the VPN object is created. They will need to be created as VPC routes using this VPN connection (refer to the Static Routes section).

10. Repeat the same process using your second Cloudflare anycast IP.

Static Routes

Static routing is necessary to route traffic between your VPN and Cloudflare Magic WAN. Follow these steps to create them for your VPC. Refer to VPN route documentation to learn more about VPN routing.

1. Go to VPN Network > Routes.
2. Select Route Management.
3. Create a route.
4. Choose the VPC network you want to use for that route.
5. In Route type select Static Routing.
6. In IP Version select IPv4.
7. Configure the network you want to expose to your VPN in the Destination IPv4 Range.
8. Choose a priority for your static route.
9. (Optional) You can link that route to a specific instance tag, so only impacted instances will use that route.
10. In Next hop select the VPN tunnel you created previously.
11. Select Create.

Magic WAN

After configuring the Cloud VPN gateway VPN and the tunnels as mentioned above, go to the Cloudflare dashboard and create the corresponding IPsec tunnels and static routes on the Magic WAN side.

IPsec tunnels

1. Refer to Add tunnels to learn how to add an IPsec tunnel. When creating your IPsec tunnel, make sure you define the following settings:
   • Tunnel name: tunnel01
   • Interface address: The IPsec tunnel inner /30CIDR block. For example, 169.254.244.2.
   • Customer endpoint: The IP address from GCP VPN tunnel outside IP address. For example, 35.xx.xx.xx.
   • Cloudflare endpoint: Enter the first of your two anycast IPs.
   • Pre-shared key: Choose Use my own pre-shared key, and enter the PSK you created for the GCP VPN tunnel.
   • Health check type: Choose Reply
   • Health check destination: Choose custom and set the IP corresponding to the interface address for the tunnel
   • Health check direction: Choose Bidirectional
   • Replay protection: Select Enabled.
2. Select Save.
3. Repeat the above steps for tunnel02. Chose the same prefix, but select the second IPsec tunnel for Tunnel/Next hop.

Note

Do not forget to create a route in the corresponding GCP VPC covering for the healthcheck configuration of the tunnel. The route subnet should match the interface address CIDR of the Magic WAN tunnel (169.254.244.2 in the example above).

Refer to the Static Routes section for more detail on how to create a VPC route leading to your newly created tunnel.

Static routes

The static route in Magic WAN should point to the appropriate virtual machine (VM) subnet you created inside your GCP virtual private cloud. For example, if your VM has a subnet of 192.168.192.0/26, you should use it as the prefix for your static route.

To create a static route:

1. Refer to Create a static route to learn how to create one.
2. In Prefix, enter the subnet for your VM. For example, 192.xx.xx.xx/24.
3. For the Tunnel/Next hop, choose the IPsec tunnel you created in the previous step.
4. Repeat the steps above for the second IPsec tunnel you created.