Creating the internal LB

To create the internal LB:

1. Go to Network Services > Load balancing and click CREATE A LOAD BALANCER.
2. In TCP Load Balancing, click START CONFIGURATION.
3. Change the Internet-facing or internal only option to Only between my VMs and click CONTINUE.
4. Name your load balancer (LB) and select the region where FortiGates are running.
5. From the Network dropdown list, select the INTERNAL_VPC network.
6. Configure the backend:
   1. Under Backends, create a new backend. Select the first instance group and click DONE. Ignore the warning about the instance group having a different primary network.
   2. Click ADD BACKEND and add the second instance group to the backend list.
   3. From the health check dropdown list, select the health check that you created for the external LB.
7. Switch to frontend configuration and change Port to All.
8. From the Subnetwork dropdown list, select SUBNET_INT. Click Done.
9. Click CREATE.