Module 5

Module 5 of the Cloud Academy is complete, so let’s recap what we covered

AWS Global Infrastructure

We explored several components that make up AWS’s global infrastructure, which enables users to build and deploy highly available, scalable, and resilient applications worldwide.

• AWS Regions are geographic areas where AWS clusters its data centers. Each region is isolated from the others, ensuring fault tolerance and stability of AWS resources.
• AWS Availability Zones (AZs) are independent data centers within an AWS region. These operate separately, so if one AZ fails, the others remain unaffected.
• AWS Local Zones bring AWS services closer to end users for latency-sensitive applications.
• AWS Edge Locations are distributed data centers designed to cache content, allowing data to be delivered with the lowest possible latency to users globally.

AWS VPC (Virtual Private Cloud)

A VPC is a logically isolated, private network on the AWS Cloud, giving us full control over our resources and network environment. Here’s an overview of some key VPC components:

• CIDR Block: This defines the IP address range of the VPC, which determines how many resources can be created within it.
• Subnets: These are divisions within the VPC. A public subnet is accessible from the internet, while a private subnet is not. Multiple subnets can be used, such as public ones for front-end applications and private ones for back-end systems or databases.
• Internet Gateway (IGW): Allows internet access for resources in public subnets.
• NAT Gateway: Enables resources in private subnets to send outbound traffic to the internet, while preventing inbound internet traffic.
• Route Tables: Used to control the flow of traffic within the VPC, route tables can be assigned to subnets to direct traffic to the appropriate destination.
• Security Groups: These control the inbound and outbound traffic to resources within the VPC. Security groups are stateful, meaning return traffic is automatically allowed without explicit rules.
• NACL (Network Access Control List): Similar to security groups but at the subnet level, NACLs control traffic in and out of subnets. Unlike security groups, NACLs are stateless, so explicit rules must be set to allow return traffic.

This week provided a strong foundation in understanding how AWS’s global infrastructure and VPCs work together to deliver scalable, secure, and resilient applications.

Week 5 Project

Project 1: VPC Design with Multiple Availability Zones

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The goal of this project was to design a VPC across two availability zones (AZs). Each AZ was required to have:

- One public subnet
- Two private subnets (an Application Subnet and a Database Subnet)

Steps Involved:
1. VPC Configuration:
— Set up an Internet Gateway to enable internet access for the public subnet.
— Configure a Route Table for directing traffic in the VPC.
— Set up a NAT Gateway in the public subnet to allow instances in the private subnets to access the internet securely.
— Configure a Security Group to manage access control for the instances.

2. EC2 Instance Setup:
— Deploy EC2 instances in the private subnets (Application Subnet) across both availability zones.
— Deploy a Bastion Host in one of the public subnets to securely manage access to the private instances.

3. Testing Connectivity:
— SSH into the Bastion Host from the internet.
— From the Bastion Host, SSH into the EC2AppServer1 instance located in the private subnet of the first availability zone.
— Once connected to EC2AppServer1, test connectivity by pinging EC2AppServer2, which is in the private subnet of the second availability zone.

The successful connection and ping test confirmed the network setup and communication between the two availability zones.