We already covered networking in Chapter 8, Networking Options in GCP, but we would like to recap what is important from a security standpoint.
If Compute Engine instances don't need to communicate with each other, then we should host them on different Virtual Private Cloud (VPC) networks. Additionally, if we have an application made up of servers on different network tiers, then each server should be on a different subnet. Let's take a traditional web app and DB application as an example. We want to segment each tier on a different subnet.
Firewall rules are the obvious choice for securing a network. As you now know, a VPC lets you isolate your network to allow for segmentation between computing resources. Firewall rules let you control the flow of inbound and outbound traffic by allowing or denying the traffic based on direction, source...
