Before migrating domains to Amazon’s Route53, we should first make sure we properly understand how DNS works
While we’ll get to AWS’s Route53 Domain Name System (DNS) service in the second part of this series, I thought it would be helpful to first make sure that we properly understand just how DNS works in general. Once we’re comfortable with the DNS process and terminology, we’ll explore migrating existing domains to Route53.
The DNS provides mapping between human-readable names (like www.amazon.com) and their associated IP addresses (like 22.214.171.124). DNS can be best compared to a phone book where you look up the phone numbers listed by easier-to-remember names. DNS comes under the application layer protocol.
A user types www.amazon.com in his browser, which then queries the DNS server for amazon.com’s IP addresses. The servers return Amazon’s address so the browser can request data from Amazon’s web host, which returns the elements necessary to build their home page in the local browser.
How DNS Works: Domain Name System Terminology
A domain name is a human-readable name—like amazon.com—that we type in a web browser URL field. The Internet Corporation for Assigned Names and Numbers (ICANN) manages these domain names
Top Level Domain (TLD)
TLD refers to the last part of a domain name. For example, the .com in amazon.com is the Top Level Domain. The most common TLDs include .com, .net, org, and .info. Country code TLDs represent specific geographic locations. For example: .in represents India. Here are some more examples:
- com – Commercial businesses.
- gov – U.S. government agencies.
- edu – Educational institutions such as universities.
- org – Organizations (mostly non-profit).
- mil – Military.
- net – Network organizations.
- eu – European Union.
Second Level Domain
This is the part of a domain name which comes right before the TLD—amazon.com—for example.
A subdomain can be created to identify unique content areas of a web site. For example, the aws of aws.amazon.com.
By managing domain name reservations, name registrars are critical to how DNS works. ICANN currently grants permission to organizations to act as domain name registrars for specific higher level domains.
Like a phone book, the name server is a collection of domain names matched to IP addresses.
How DNS Works: Domain Name System record types
Address record. A Records map server IP addresses to domain names. For example, 126.96.36.199 to amazon.com.
Canonical Name record. A CNAME record establishes one domain as an alias to another (thereby routing all traffic addressed to the alias to the target; the canonical address).
Like a CNAME record, Alias records can be used to map one address to another. But Aliases can coexist with other records using the same name.
Mail Exchange Record. These records will redirect a domain’s email to the servers hosting the domain’s user accounts. Mail exchange records are used for determining the priority of email servers for a domain.
How DNS Works
When a user types a human-readable address into the browser, the operating system’s DNS client will check for information in a local cache. If the requested address isn’t there, it will look for a Domain Name System server in the local area network (LAN). When the local DNS server receives the query, and the requested domain name is found, it will return the result.
If the name is not found, the local server will forward the query to a DNS cache server, often provided by the Internet Service Provider (ISP). Since the DNS server’s cache contains a temporary store of DNS records, it will quickly respond to requests. These DNS cache servers are called not authoritative DNS servers as they provide request resolution based in a cached value acquired from authoritative DNS servers.
An Authoritative Root Name Server maintains and provides a list of authoritative name servers for each of the top-level domains (.com, .org, etc.).
An Authoritative Top Level Domain Name Server maintains and provides a list of authoritative name servers for all domains (gmail.com, wikipedia.org, etc.). Its job is to query name servers to find and return the authoritative name server for the requested domain.
Now that we’ve got a better idea of how DNS works, the next post will introduce you Amazon’s Route53 and show you how easy it can be to migrate your existing domains to it.
If you’re new to Amazon Route53, this is your go-to course Working with AWS’s Domain Name System: Amazon Route 53
Which Certifications Should I Get?
As we mentioned in an earlier post, 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 compan...
New Content: AWS, Azure, Typescript, Java, Docker, 13 New Labs, and Much More
This month, our Content Team released a whopping 13 new labs in real cloud environments! If you haven't tried out our labs, you might not understand why we think that number is so impressive. Our labs are not “simulated” experiences — they are real cloud environments using accounts on A...
Kickstart Your Tech Training With a Free Week on Cloud Academy
Are you looking to make a jump in your technical career? Want to get trained or certified on AWS, Azure, Google Cloud Platform, DevOps, Kubernetes, Python, or another in-demand skill?Then you'll want to mark your calendar. Starting Monday, June 22 at 12:00 a.m. PDT (3:00 a.m. EDT), ...
New Content: AZ-500 and AZ-400 Updates, 3 Google Professional Exam Preps, Practical ML Learning Path, C# Programming, and More
This month, our Content Team released tons of new content and labs in real cloud environments. Not only that, but we introduced our very first highly interactive "Office Hours" webinar. This webinar, Acing the AWS Solutions Architect Associate Certification, started with a quick overvie...
Azure vs. AWS: Which Certification Provides the Brighter Future?
More and more companies are using cloud services, prompting more and more people to switch their current IT position to something cloud-related. The problem is most people only have that much time after work to learn new technologies, and there are plenty of cloud services that you can ...
Blog Digest: 5 Reasons to Get AWS Certified, OWASP Top 10, Getting Started with VPCs, Top 10 Soft Skills, and More
Thank you for being a valued member of our community! We recently sent out a short survey to understand what type of content you would like us to add to Cloud Academy, and we want to thank everyone who gave us their input. If you would like to complete the survey, it's not too late. It ...
New Content: Alibaba, Azure Cert Prep: AI-100, AZ-104, AZ-204 & AZ-400, Amazon Athena Playground, Google Cloud Developer Challenge, and much more
This month, our Content Team released 8 new learning paths, 4 courses, 7 labs in real cloud environments, and 4 new knowledge check assessments. Not only that, but we introduced our very first course on Alibaba Cloud, and our expert instructors are working 'round the clock to create 6 n...
Top 5 Reasons to Get AWS Certified Right Now
Cloud computing trends are on the rise and have been for some time already. Fortunately, it’s never too late to start learning cloud computing. Skills like AWS and others associated with cloud computing are in high demand because cloud technologies have become crucial for many businesse...
Introducing Our Newest Lab Environments: Lab Playgrounds
Want to train in a real cloud environment, but feel slowed down by spinning up your own deployments? When you consider security or pricing costs, it can be costly and challenging to get up to speed quickly for self-training. To solve this problem, Cloud Academy created a new suite of la...
Blog Digest: AWS Breaking News, Azure DevOps, AWS Study Guide, 8 Ways to Prevent a Ransomware Attack, and More
New articles by topicAWS Azure Data Science Google Cloud Cloud Adoption Platform Updates & New Content Security Women in TechAWSBreaking News: All AWS Certification Exams Now Available Online As an Advanced AWS Technology Partner, C...
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, though you can still take SAA-C01 through July 1, 2020. This post will focus on version SAA-C02.The AWS...
New on Cloud Academy: AWS Solutions Architect Exam Prep, Azure Courses, GCP Engineer Exam Prep, Programming, and More
Free content on Cloud Academy More and more customers are relying on our technology and content to keep upskilling their people in these months, and we are doing our best to keep supporting them. While the world fights the COVID-19 pandemic, we wanted to make a small contribution to he...