Deploying firewall rules in GCP

GCP offers a variety of tools to enforce security within customer environments. Among these, firewall rules are one of the fundamental security mechanisms provided by GCP, serving as the first line of defense for all workloads within a VPC. In this recipe, you will walk through defining and provisioning firewall rules in the GCP cloud.

In GCP, firewall rules are stateful, meaning they automatically track the state of network connections and apply rules accordingly. These rules are applied to hosts within a VPC and can operate in either the ingress or egress direction. By default, GCP creates the following firewall rules for any new custom VPC:

• Ingress direction: A default rule denies all incoming traffic destined for any host within the VPC
• Egress direction: A default rule allows all outgoing traffic from any host within the VPC

With these default rules, and since GCP’s firewall rules are stateful, any traffic initiated...