Virtual Private Clouds and the AWS Solutions Architect exam

Virtual Private Cloud architecture is critically important for passing the Solutions Architect exam

A solid understanding of Virtual Private Cloud (VPC) architecture is central to just about everything connected to the Amazon Web Services universe. But if you’re thinking of taking the AWS Solutions Architect Associate level exam, it’s critical.
In this post, I will explain why I believe this to be true and specify which VPC elements will require your greatest focus if you’re serious about passing this exam.
Take a look at the AWS Solutions Architect exam blueprint. You will see a table breaking the exam material down into four areas:

Designing highly available, cost efficient, fault tolerant, scalable systems.60%
Data Security.20%

As you can see, 60% of the exam is specifically focused on Designing highly available, cost efficient, fault tolerant, scalable systems. In my experience, what that really means is…understand the virtual private cloud.
So let’s outline the virtual private cloud elements I think are the most critical.

1. Security Groups and Network ACLs

Amazon virtual private clouds come with two built-in security tools:

  • Security groups work at the instance level to control all traffic into and out of associated Amazon EC2 instances.
  • Network access control lists (ACLs) work at the subnet level to control all traffic into and out of associated subnets.

As a complete guide to VPC security is way beyond the scope of this post, be sure to read through the excellent Amazon documentation on the subject. Not to mention, of course, the relevant material from this Cloud Academy course.
For now, here’s an excellent illustrative diagram from Amazon’s documentation:

Virtual Private Cloud
An example of virtual private cloud networking with Security Groups, Subnets, Network ACL, Routing tables, VPG and Internet Gateway


2. Public and Private IP Addresses

Make sure you understand the difference between public and private IP addresses. Simply put: private IP addresses are not accessible from the Internet, but are used for communication between instances within your virtual private cloud. Public IP addresses, on the other hand, are accessible from the Internet and can be used for communication between your instances and the Internet, or with other AWS services that have public endpoints.
The Solutions Architect exam may contain some tricky IP-related questions. You might be expected to know how to connect a private IP to the internet or to understand how specific protocols can affect connectivity. You’ll also need to understand how public and private IP Addresses interact with Security Groups and Network ACLs.
Again, AWS documentation and Cloud Academy courses are your two best friends here.

3. NAT Instances

You are almost certain to see at least one Network Address Translation (NAT) question on the exam. How, for instance, can you connect an instance from a private subnet to the internet (to allow software updates)? You could create a special NAT instance in a public subnet in your virtual private cloud to provide controlled outbound connectivity to instances in the private subnet while restricting all inbound traffic.
If you’ve never set up a virtual private cloud on AWS, I suggest that you do it now. Play around with various VPC configuration profiles to see for yourself how your public and private networks interact between themselves and the outside world.

4. Virtual private cloud peering

A VPC peering connection is a networking connection between two virtual private clouds that enables you to route traffic between them using private IP addresses. This configuration scenario is important enough that you might face a related question on the exam. Again, the best option is to play around on the AWS console and try and set up 2 or more VPC’s and then play around with routing traffic between them using private IP addresses.

Conclusion and other virtual private cloud concepts

I cannot over state the importance of fully understanding VPCs for passing the AWS Solutions Architect Associate exam. This article obviously doesn’t cover the whole topic. You’ll still need to work on other pieces of the puzzle like Network Interfaces, Route tables and Internet gateways, and how they all interact with each other.
The AWS exam is well designed as a challenging test of your practical skills. As there are very few obvious or easy answers, you should definitely not take passing for granted, and perhaps more than any other topic, you should focus your preparations on  VPC.

Written by

Michael Sheehy

I have been UNIX/Linux System Administrator for the past 15 years and am slowly moving those skills into the AWS Cloud arena. I am passionate about AWS and Cloud Technologies and the exciting future that it promises to bring.

Related Posts

— February 11, 2019

WaitCondition Controls the Pace of AWS CloudFormation Templates

AWS's WaitCondition can be used with CloudFormation templates to ensure required resources are running.As you may already be aware, AWS CloudFormation is used for infrastructure automation by allowing you to write JSON templates to automatically install, configure, and bootstrap your ...

Read more
  • AWS
— January 24, 2019

The 9 AWS Certifications: Which is Right for You and Your Team?

As companies increasingly shift workloads to the public cloud, cloud computing has moved from a nice-to-have to a core competency in the enterprise. This shift requires a new set of skills to design, deploy, and manage applications in the cloud.As the market leader and most mature p...

Read more
  • AWS
  • AWS certifications
— November 28, 2018

Two New EC2 Instance Types Announced at AWS re:Invent 2018 – Monday Night Live

The announcements at re:Invent just keep on coming! Let’s look at what benefits these two new EC2 instance types offer and how these two new instances could be of benefit to you. If you're not too familiar with Amazon EC2, you might want to familiarize yourself by creating your first Am...

Read more
  • AWS
  • EC2
  • re:Invent 2018
— November 21, 2018

Google Cloud Certification: Preparation and Prerequisites

Google Cloud Platform (GCP) has evolved from being a niche player to a serious competitor to Amazon Web Services and Microsoft Azure. In 2018, research firm Gartner placed Google in the Leaders quadrant in its Magic Quadrant for Cloud Infrastructure as a Service for the first time. In t...

Read more
  • AWS
  • Azure
  • Google Cloud
Khash Nakhostin
— November 13, 2018

Understanding AWS VPC Egress Filtering Methods

In order to understand AWS VPC egress filtering methods, you first need to understand that security on AWS is governed by a shared responsibility model where both vendor and subscriber have various operational responsibilities. AWS assumes responsibility for the underlying infrastructur...

Read more
  • Aviatrix
  • AWS
  • VPC
— November 10, 2018

S3 FTP: Build a Reliable and Inexpensive FTP Server Using Amazon’s S3

Is it possible to create an S3 FTP file backup/transfer solution, minimizing associated file storage and capacity planning administration headache?FTP (File Transfer Protocol) is a fast and convenient way to transfer large files over the Internet. You might, at some point, have conf...

Read more
  • Amazon S3
  • AWS
— October 18, 2018

Microservices Architecture: Advantages and Drawbacks

Microservices are a way of breaking large software projects into loosely coupled modules, which communicate with each other through simple Application Programming Interfaces (APIs).Microservices have become increasingly popular over the past few years. The modular architectural style,...

Read more
  • AWS
  • Microservices
— October 2, 2018

What Are Best Practices for Tagging AWS Resources?

There are many use cases for tags, but what are the best practices for tagging AWS resources? In order for your organization to effectively manage resources (and your monthly AWS bill), you need to implement and adopt a thoughtful tagging strategy that makes sense for your business. The...

Read more
  • AWS
  • cost optimization
— September 26, 2018

How to Optimize Amazon S3 Performance

Amazon S3 is the most common storage options for many organizations, being object storage it is used for a wide variety of data types, from the smallest objects to huge datasets. All in all, Amazon S3 is a great service to store a wide scope of data types in a highly available and resil...

Read more
  • Amazon S3
  • AWS
— September 18, 2018

How to Optimize Cloud Costs with Spot Instances: New on Cloud Academy

One of the main promises of cloud computing is access to nearly endless capacity. However, it doesn’t come cheap. With the introduction of Spot Instances for Amazon Web Services’ Elastic Compute Cloud (AWS EC2) in 2009, spot instances have been a way for major cloud providers to sell sp...

Read more
  • AWS
  • Azure
  • Google Cloud
  • SpotInst
— August 23, 2018

What are the Benefits of Machine Learning in the Cloud?

A Comparison of Machine Learning Services on AWS, Azure, and Google CloudArtificial intelligence and machine learning are steadily making their way into enterprise applications in areas such as customer support, fraud detection, and business intelligence. There is every reason to beli...

Read more
  • AWS
  • Azure
  • Google Cloud
  • Machine Learning
— August 17, 2018

How to Use AWS CLI

The AWS Command Line Interface (CLI) is for managing your AWS services from a terminal session on your own client, allowing you to control and configure multiple AWS services.So you’ve been using AWS for awhile and finally feel comfortable clicking your way through all the services....

Read more
  • AWS