Managed NAT Gateway: Simplifying Secure AWS Connectivity

Creating and maintaining connectivity for the resources in your private AWS subnets can be tricky and expensive. AWS’ new managed NAT Gateway is a great alternative.

Good news for all the folks working in the AWS VPC environment: the managed NAT gateway is here. I have been working in the AWS cloud for a long time and one of the most common requirements for the applications I’ve deployed is providing Internet connectivity from resources in a VPC’s private subnet. For those unfamiliar with how this works, let me briefly describe it.

Security is (or at least should be) king in AWS cloud, and the most important security tool is a properly designed VPC (Virtual private cloud):

Amazon Virtual Private Cloud (Amazon VPC) lets you provision a logically isolated section of the Amazon Web Services (AWS) Cloud where you can launch AWS resources in a virtual network that you define. You have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways.

For more background on VPCs, take Cloud Academy’s AWS VPC Networking course.
A typical VPC setup is made up of public and private subnets. The EC2 instances deployed in private subnet of VPC cannot access the Internet because you cannot assign them a public IP. But if your application servers, sitting in a private subnet, need to talk to the Internet (to interact with S3 or some third party gateway, for instance), you need NAT (Network Address Translation) to make it happen.
What we used to do is to create a NAT instance in the public subnet of the VPC and open communication with private subnet instances via NAT through VPC Routing tables. So what is the problem? Why are we all so excited about this new Managed NAT Gateway?
Performing this kind of translation at scale can be challenging. Moreover, providing higher availability through more than one NAT instance across two Availability Zones can be expensive. Consider the traditional, two-zone design:
Virtual Private Cloud
Now imagine that one of those NAT instances goes down. You’ll need to have all the automated scripts configured and ready to redirect communication from the private instances within one Availability Zone  to the NAT instance in the other one. And the more instance and AZs you’re running, the more complicated things get.

But using AWS’s new Managed NAT Gateway, things work differently. Instead of configuring, running, monitoring, and scaling a cluster of EC2 NAT instances, it’s a matter of couple of clicks and you are all set. In short, all the configurations that were once the responsibility of the developer or the Ops team, will now be handled invisibly by AWS. Developers can relax just a bit and concentrate more on their application development.

What you need to know about the AWS Managed NAT Gateway

Just as you would with any new AWS features, it only makes sense that we spend some time getting to know each other a bit better. The Managed NAT Gateway…

  • Has built-in redundancy for high availability.
  • Can handle up to 10 Gbps of bursty TCP, UDP, and ICMP traffic, and is managed by Amazon.
  • Can be used in US East (Northern Virginia), US West (Oregon), US West (Northern California), Europe (Ireland), Asia Pacific (Singapore), Asia Pacific (Sydney), and Asia Pacific (Tokyo) regions (as of the time of writing).
  • Pricing starts at $0.045 per NAT gateway hour plus data processing and data transfer charges. Refer Amazon VPC pricing to get more details on this.
  • Can be associated with  a Security Group.
  • Can be controlled suing the command line or API.
  • Can be used with VPC flow logs to capture/analyze the traffic flowing through the NAT gateway.
  • Cannot be accessed by a ClassicLink connection associated with your VPC.
  • Cannot send traffic over VPC endpoints, VPN connections, AWS Direct Connect, or VPC peering connections.

Getting Started

Let’s try to see how we can create and configure an AWS NAT Gateway:

  1. Login to the AWS console, select VPC service and click on NAT Gateways as shown below:Managed NAT gateway - dashboard
  2. Provide the necessary details, like subnet and Elastic IP, and create the NAT Gateway. You need the select the subnet which you want to be private subnet and your Elastic IP so that it can communicate to Internet.NAT Gateway - create
  3. Once created you will see this:NAT Gateway - success
  4. Once the NAT Gateway is created you can edit your routing table to send traffic destined for the Internet toward the gateway. The gateway’s internal address will be chosen automatically, and will be in the same subnet as the gateway.

Once the NAT Gateway is configured, you are all set. Your private subnet instances should now be able to communicate with the Internet without much management, monitoring, and configuration overhead.
Sample NAT Gateway architecture: NAT Gateway - design

Migrating from an existing NAT instance

If you are already using a NAT instance in your VPC setup, it’s time to migrate now, and I can tell you that it’s not tough. You only need to make sure that you create the NAT Gateway in the same subnet as your existing NAT instance. Then you need to edit the route table by replacing the existing NAT reference with the  internal address of the new gateway. I told you this was very straightforward. You will need to ensure that you don’t have any critical tasks running at the time of migration, because changing a route from a NAT instance to the gateway can result in a dropped connection.

This feature was only very recently introduced by AWS, so it’s definitely worth sharing. It can resolve lots of existing concerns. Do you have your own experience with this new feature? Why not share it with others.

Avatar

Written by

Vineet Badola

Working as a cloud professional for last 6 years in various organizations, I have experience in three of the most popular cloud platforms, AWS IaaS, Microsoft Azure and Pivotal Cloud Foundry PaaS platform. Having around 10 years of IT experience in various roles and I take great interest in learning and sharing my knowledge on newer technologies. Wore many hats as developer, lead, architect in cloud technologies implementation. During Leisure time I enjoy good soothing music, playing TT and sweating out in Gym. I believe sharing knowledge is my way to make this world a better place.


Related Posts

Amanda Cross
Amanda Cross
— April 9, 2021

New Content: Platforms, Programming, and DevOps – Something for Everyone

This month our team of expert certification specialists released three new or updated learning paths, 16 courses, 13 hands-on labs, and four lab challenges! New content on Cloud Academy You can always visit our Content Roadmap to see what’s just released as well as what’s coming soon....

Read more
  • alibaba
  • AWS
  • Azure
  • DevOps
  • Google Cloud Platform
  • programming
  • Security
Luca Casartelli
Luca Casartelli
— March 31, 2021

Mastering AWS Organizations Service Control Policies

Service Control Policies (SCPs) are IAM-like policies to manage permissions in AWS Organizations. SCPs restrict the actions allowed for accounts within the organization making each one of them compliant with your guidelines. SCPs are not meant to grant permissions; you should consider ...

Read more
  • AWS
  • Organizations
  • SCP
Amanda Cross
Amanda Cross
— March 12, 2021

New Content: Focus on DevOps and Programming Content this Month

This month our team of expert certification specialists released 12 new or updated learning paths, 15 courses, 25 hands-on labs, and four lab challenges! New content on Cloud Academy You can always visit our Content Roadmap to see what’s just released as well as what’s coming soon. Ja...

Read more
  • alibaba
  • AWS
  • Azure
  • DevOps
  • Google Cloud Platform
  • programming
Amanda Cross
Amanda Cross
— February 12, 2021

New Content: Get Ready for the CISM Cert Exam & Learn About Alibaba, Plus All the AWS, GCP, and Azure Courses You Know You Can Count On

This month our team of intrepid certification specialists released five learning paths, seven courses, 19 hands-on labs, and three lab challenges!  One particularly interesting new learning path is Certified Information Security Manager (CISM) Foundations. After completing this learn...

Read more
  • alibaba
  • AWS
  • Azure
  • cism
  • DevOps
  • Google Cloud Platform
  • programming
Avatar
Cloud Academy Team
— January 31, 2021

Which Certifications Should I Get?

The old AWS slogan, “Cloud is the new normal” is indeed a reality today. Really, cloud has been the new normal for a while now and getting credentials has become an increasingly effective way to quickly showcase your abilities to recruiters and companies. With all that in mind, the s...

Read more
  • AWS
  • Azure
  • Certifications
  • Cloud Computing
  • Google Cloud Platform
Avatar
Andrew Larkin
— January 31, 2021

The 12 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 cloud computing. As the market leader and most ma...

Read more
  • AWS
  • AWS Certifications
Avatar
Stuart Scott
— January 29, 2021

AWS Certified Solutions Architect Associate: A Study Guide

Want to take a really impactful step in your technical career? Explore the AWS Solutions Architect Associate certificate. Its new version (SAA-C02) was released on March 23, 2020. The AWS Solutions Architect - Associate Certification (or Sol Arch Associate for short) offers some ...

Read more
  • AWS
  • AWS Certifications
  • AWS Certified Solutions Architect Associate
Amanda Cross
Amanda Cross
— January 7, 2021

New Content: AWS Terraform, Java Programming Lab Challenges, Azure DP-900 & DP-300 Certification Exam Prep, Plus Plenty More Amazon, Google, Microsoft, and Big Data Courses

This month our Content Team continues building the catalog of courses for everyone learning about AWS, GCP, and Microsoft Azure. In addition, this month’s updates include several Java programming lab challenges and a couple of courses on big data. In total, we released five new learning...

Read more
  • AWS
  • Azure
  • DevOps
  • Google Cloud Platform
  • Machine Learning
  • programming
Avatar
Stuart Scott
— December 17, 2020

Where Should You Be Focusing Your AWS Security Efforts?

Another day, another re:Invent session! This time I listened to Stephen Schmidt’s session, “AWS Security: Where we've been, where we're going.” Amongst covering the highlights of AWS security during 2020, a number of newly added AWS features/services were discussed, including: AWS Audit...

Read more
  • AWS
  • AWS re:Invent
  • cloud security
Joe Nemer
Joe Nemer
— December 4, 2020

AWS re:Invent: 2020 Keynote Top Highlights and More

We’ve gotten through the first five days of the special all-virtual 2020 edition of AWS re:Invent. It’s always a really exciting time for practitioners in the field to see what features and services AWS has cooked up for the year ahead.  This year’s conference is a marathon and not a...

Read more
  • AWS
  • AWS Glue Elastic Views
  • AWS re:Invent
Bryony Harrower
Bryony Harrower
— November 6, 2020

WARNING: Great Cloud Content Ahead

At Cloud Academy, content is at the heart of what we do. We work with the world’s leading cloud and operations teams to develop video courses and learning paths that accelerate teams and drive digital transformation. First and foremost, we listen to our customers’ needs and we stay ahea...

Read more
  • AWS
  • Azure
  • content roadmap
  • GCP
Joe Nemer
Joe Nemer
— October 25, 2020

Excelling in AWS, Azure, and Beyond – How Danut Prisacaru Prepares for the Future

Meet Danut Prisacaru. Danut has been a Software Architect for the past 10 years and has been involved in Software Engineering for 30 years. He’s passionate about software and learning, and jokes that coding is basically the only thing he can do well (!). We think his enthusiasm shines t...

Read more
  • AWS
  • careers
  • champions
  • upskilling