Full Guide to Understanding Your AWS VPC

AWS VPC is a virtual networking environment that is dedicated to your AWS account and provides a secure, isolated section of the AWS cloud.

Amazon Virtual Private Cloud (VPC) lets you provision a logically isolated section of the AWS Cloud where you can launch AWS resources in a virtual network that you define.

Key VPC Components

Subnets

A subnet is a range of IP addresses in your VPC. You can launch AWS resources into a specified subnet. Use a public subnet for resources that must be connected to the internet, and a private subnet for resources that won't be connected to the internet.

Route Tables

A route table contains a set of rules, called routes, that are used to determine where network traffic is directed. Each subnet in your VPC must be associated with a route table.

Internet Gateway

An internet gateway is a horizontally scaled, redundant, and highly available VPC component that allows communication between your VPC and the internet.

NAT Gateway

A NAT gateway enables instances in a private subnet to connect to the internet or other AWS services, but prevents the internet from initiating a connection with those instances.

Security in VPC

Security Groups

A security group acts as a virtual firewall for your instance to control inbound and outbound traffic. Security groups act at the instance level, not the subnet level.

Network ACLs

A network access control list (ACL) is an optional layer of security for your VPC that acts as a firewall for controlling traffic in and out of one or more subnets.

Best Practices

• Use multiple Availability Zones for high availability
• Use private subnets for backend resources
• Implement least privilege access with security groups
• Enable VPC Flow Logs for network monitoring
• Use VPC endpoints for AWS service access