AWS VPC (Virtual Private Cloud)

What is AWS VPC?

AWS VPC (Virtual Private Cloud) is a service that allows you to launch AWS resources in a logically isolated virtual network. With VPC, you can define and control your virtual network environment, including IP address ranges, subnets, route tables, and network gateways.

Why Use AWS VPC?

AWS VPC allows you to isolate and securely connect your applications in the cloud. Here are the key benefits:

  • Isolation: You can create isolated networks for different applications or environments (e.g., development, staging, production).
  • Security: VPC provides fine-grained control over network security using security groups, NACLs, and VPN connections.
  • Customizable: Define your own IP address range, create subnets, and manage routing within the network.
  • Connectivity: Establish connections to your on-premises infrastructure using VPN, Direct Connect, or VPC Peering.

Components of a VPC

A VPC consists of several components that help define and control the network:

  • Subnets: Subdivide your VPC into sub-networks (private and public).
  • Internet Gateway (IGW): Allows resources in a VPC to connect to the internet.
  • Route Tables: Define how traffic flows within your VPC and to/from the internet.
  • Security Groups: Acts as a virtual firewall to control inbound and outbound traffic.
  • Network ACLs: Adds an additional layer of security at the subnet level.
  • VPC Peering: Allows you to connect multiple VPCs for cross-VPC communication.

Creating a VPC

Follow these steps to create a simple VPC in AWS:

  1. Go to the AWS VPC Console.
  2. Click Create VPC.
  3. Specify the IP CIDR block for your VPC (e.g., 10.0.0.0/16).
  4. Choose whether you want to create a public subnet, private subnet, or both.
  5. Click Create VPC to complete the process.

Example: Creating a VPC Using AWS CLI

Here’s how to create a VPC using the AWS CLI:


aws ec2 create-vpc --cidr-block 10.0.0.0/16 --amazon-provided-ipv6-cidr-block

This command creates a VPC with the specified CIDR block.

Subnets and Routing

After creating a VPC, you can divide it into multiple subnets. You can create both public and private subnets:

  • Public Subnet: A subnet that is connected to the internet via an internet gateway. Instances in this subnet can directly access the internet.
  • Private Subnet: A subnet that is isolated from the internet. Instances in this subnet cannot directly access the internet but can access it through a NAT gateway or NAT instance.

After creating the subnets, you must update the route table to allow communication between the VPC and the internet.

Security in VPC

Security is a key feature of AWS VPC. You can control the traffic between instances using:

  • Security Groups: Virtual firewalls for controlling inbound and outbound traffic to instances.
  • Network ACLs (Access Control Lists): An additional layer of security at the subnet level.
  • VPC Flow Logs: Logs of all traffic in and out of your VPC, helpful for monitoring and troubleshooting network security.

VPC Peering

VPC Peering allows two VPCs to connect and communicate as if they were within the same network. It is a simple and cost-effective method for enabling cross-region or cross-account communication.

To create a VPC Peering connection, you need to:

  1. Navigate to the VPC Console and click on Peering Connections.
  2. Click Create Peering Connection, choose the VPCs you want to connect, and create the connection.
  3. Update the route tables to enable routing between the peered VPCs.

Conclusion

AWS VPC is an essential service for managing the networking environment in AWS. It allows for secure, scalable, and highly customizable network setups, enabling users to control IP addresses, routing, subnets, and security in their virtual environment.

Next Topic: AWS IAM (Identity and Access Management)

In the next lesson, we will explore AWS IAM, which is used to manage users, roles, and permissions for your AWS resources.