Private Google Access is a small subnet-level setting that comes up on the Associate Cloud Engineer exam in a very specific scenario. This article covers what it is, how it differs from Private Service Connect (which is a different thing despite the similar name), how to enable it, and the question pattern to watch for.
It does not cover every variant of private connectivity in GCP, the full set of services Private Google Access reaches, or hybrid connectivity from on-prem. The goal is to give you the cleanest possible mental model for the ACE exam.
By default, a VM without an external IP address cannot reach the public internet. That is generally what you want for security. But Google APIs (Cloud Storage, BigQuery, Pub/Sub, and others) are accessed via public endpoints. So an internal-only VM that needs to write to a Cloud Storage bucket runs into a problem. It needs to reach a Google service, but it cannot reach the public internet.
Private Google Access fixes that. With it enabled on a subnet, VMs in that subnet can reach Google APIs over Google's internal network, without ever touching the public internet, even though those VMs have no external IP address.
Private Google Access is a setting on the subnet, not on the VM. You enable it on the subnet, and every VM in that subnet automatically gets the ability to reach Google APIs privately. There is no per-VM configuration.
The traffic path is internal. The VM sends a request to a Google API endpoint, GCP routes that traffic over its own backbone to the Google service, and the response comes back the same way. From the application's perspective, it looks like any other API call. From a network-security standpoint, the traffic never leaves Google's network.
Private Google Access and Private Service Connect sound similar but are different things. They are easy to confuse and the exam occasionally tests whether you can keep them straight.
Private Google Access lets internal VMs reach Google's first-party APIs (Cloud Storage, BigQuery, and so on) at their public hostnames, but routed privately. It is a subnet-level toggle. Free.
Private Service Connect is a more general mechanism for exposing services privately, including third-party services, your own services, and Google services through private endpoints with custom IPs and DNS. It is a more elaborate setup with consumer endpoints and producer services.
For the Associate Cloud Engineer exam, Private Google Access is the one that comes up most often. If a scenario describes internal VMs needing to reach Google APIs without external IPs, Private Google Access is almost always the right answer.
You enable Private Google Access when creating a subnet, or by updating an existing subnet:
gcloud compute networks subnets update my-subnet \
--region=us-central1 \
--enable-private-ip-google-accessThat is the whole setup. No per-VM changes, no firewall rule changes (unless you have egress rules that block traffic to Google APIs, which would be unusual). Once the subnet has Private Google Access on, every VM in it can reach Google services privately.
The Associate Cloud Engineer exam pattern is consistent. A scenario describes a VM that needs to reach a Google service like Cloud Storage or BigQuery, but the VM should not have a public IP for security or compliance reasons. The question asks how to make this work.
The answer is to enable Private Google Access on the subnet where that VM lives. The wrong answers usually involve giving the VM an external IP (which violates the security requirement) or setting up a NAT gateway (which works for general internet access but is heavier than needed for just Google APIs).
If you see "VM with internal IP only" plus "needs to reach Google APIs" in a question, think Private Google Access. If you see "VM needs to reach the public internet generally" without an external IP, think Cloud NAT instead. Those are different problems with different solutions.
Private Google Access is for traffic to Google APIs. It does not give the VM access to other public internet destinations. If your application needs to call a non-Google service (a third-party API, an external webhook), Private Google Access does not help. You would use Cloud NAT for that, or give the VM an external IP, or use a proxy.
The exam occasionally tests this distinction by describing a workload that needs both Google API access AND access to a third-party service. The answer there is Cloud NAT (which covers both), not Private Google Access alone.
Private Google Access is a subnet-level setting that lets VMs without external IPs reach Google APIs over Google's internal network. It is the right answer when a scenario calls for internal-only VMs that still need to interact with Cloud Storage, BigQuery, Pub/Sub, or other Google services. It is different from Private Service Connect, which is a broader and more elaborate private connectivity mechanism, and different from Cloud NAT, which handles general outbound internet access.
If you see "internal VM" plus "Google API access" plus "no external IP" together in an Associate Cloud Engineer exam question, the setting being tested is Private Google Access.
My Associate Cloud Engineer course covers Private Google Access in the VPC and networking section alongside Cloud NAT, Shared VPC, and the other connectivity patterns the exam tests.
