Firewall rules concept in GCP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a firewall rule in Google Cloud Platform?

A firewall rule in GCP controls the traffic allowed to and from virtual machine instances by specifying which connections are permitted or denied based on IP addresses, ports, and protocols.

beginner

What are the main components of a GCP firewall rule?

The main components are: direction (ingress or egress), priority (order of evaluation), action (allow or deny), targets (which instances the rule applies to), source or destination IP ranges, protocols, and ports.

intermediate

How does priority affect firewall rules in GCP?

Priority is a number where lower values have higher priority. GCP evaluates rules from lowest to highest priority and applies the first matching rule to the traffic.

beginner

What is the difference between ingress and egress firewall rules?

Ingress rules control incoming traffic to instances, while egress rules control outgoing traffic from instances.

intermediate

Why is it important to specify targets in firewall rules?

Specifying targets ensures that the firewall rule applies only to certain VM instances or groups, helping to limit exposure and improve security.

In GCP firewall rules, what does a lower priority number mean?

A Only applies to egress rules

B Lower priority, evaluated last

C No effect on evaluation order

D Higher priority, evaluated first

Lower priority numbers mean higher priority and are evaluated before rules with higher numbers.

Which direction does an ingress firewall rule control?

A Outgoing traffic from VM instances

B Incoming traffic to VM instances

C Traffic between VPC networks

D Traffic to Google APIs only

Ingress rules control incoming traffic to VM instances.

What action can a firewall rule perform in GCP?

A Redirect traffic

B Only allow traffic

C Allow or deny traffic

D Only deny traffic

Firewall rules can either allow or deny traffic based on the rule configuration.

Why should you specify IP ranges in a firewall rule?

A To define which traffic sources or destinations are affected

B To speed up network traffic

C To encrypt data in transit

D To assign IP addresses to VMs

IP ranges specify which sources or destinations the rule applies to, controlling traffic flow.

What happens if no firewall rule matches the ingress traffic in GCP?

A Traffic is denied by default

B Traffic is allowed by default

C Traffic is logged but allowed

D Traffic is redirected to a default route

By default, GCP denies ingress traffic that does not match any firewall rule.

Explain how firewall rules control traffic in Google Cloud Platform.

Think about how rules decide which traffic is allowed or blocked.

Describe the importance of priority and targets in GCP firewall rules.

Consider how rules are applied and to which resources.