Internet Gateway for public access in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an Internet Gateway in AWS?

An Internet Gateway is a component that allows communication between instances in a VPC and the internet. It acts like a door for public internet access.

beginner

Why do you need an Internet Gateway for public access in AWS?

You need an Internet Gateway to let your public subnet instances send and receive traffic from the internet, like a house needing a front door to go outside.

intermediate

How do you attach an Internet Gateway to a VPC?

You create an Internet Gateway and then attach it to your VPC. This connection allows your VPC to route traffic to and from the internet.

intermediate

What route must be added to a route table for public access?

You add a route that sends all internet-bound traffic (0.0.0.0/0) to the Internet Gateway. This tells AWS to send traffic outside the VPC through the gateway.

intermediate

Can instances in private subnets access the internet through an Internet Gateway?

No, instances in private subnets cannot use the Internet Gateway directly. They need a NAT Gateway or NAT instance to access the internet safely.

What is the main purpose of an Internet Gateway in AWS?

A To monitor network traffic

B To store data securely

C To manage user permissions

D To allow VPC instances to communicate with the internet

An Internet Gateway enables instances in a VPC to send and receive traffic from the internet.

Which route destination is used to send all internet traffic to the Internet Gateway?

A 0.0.0.0/0

B 10.0.0.0/16

C 192.168.1.0/24

D 127.0.0.1/32

The route 0.0.0.0/0 means all IPv4 traffic and is used to direct internet-bound traffic to the Internet Gateway.

Can an Internet Gateway be attached to multiple VPCs at the same time?

A Yes, it can be shared across VPCs

B No, it can only be attached to one VPC

C Yes, but only in the same region

D No, it is automatically attached to all VPCs

An Internet Gateway can only be attached to one VPC at a time.

What happens if you do not attach an Internet Gateway to your VPC?

A Instances cannot access the internet

B The VPC will automatically create a NAT Gateway

C The VPC will be deleted

D Instances can still access the internet

Without an Internet Gateway, instances in the VPC cannot communicate with the internet.

Which AWS component allows private subnet instances to access the internet?

A Internet Gateway

B Elastic Load Balancer

C NAT Gateway

D Security Group

Private subnet instances use a NAT Gateway to access the internet securely.

Explain how an Internet Gateway enables public access in an AWS VPC.

Think about the path internet traffic takes from your VPC.

Describe the difference between public and private subnets regarding internet access.

Focus on how traffic flows in each subnet type.