NAT
NAT is a service that translates source and/or destination addresses when traffic passes through a routing device. In the case of GCP, NAT allows us to hide the original IP address of our VM when communicating with external networks. In the case of GCP, it allows VMs with internal addresses to access the internet.
There are currently two options for NAT, as follows:
- NAT gateway
- Cloud NAT
Google recommends using Cloud NAT over NAT gateway. If you are still using NAT gateway, Google recommends that you migrate it to Cloud NAT as it is a managed and self-scaling service.
NAT gateway
Google allows us to provision a VM that will act as a NAT gateway. This way, you are exposing only one VM to the internet. The gateway machine needs to be configured with the --can-ip-forward parameter, which allows traffic forwarding. You will also need to create default routes for the subnets that should be using the gateway. As you can see, this solution does not look scalable...
