AWS What is DNS

AWS DNS (Domain Name System) is a service that translates domain names such as www.example.com into IP addresses that computers can use to identify each other on the internet. DNS is a critical part of the internet infrastructure and is an essential service for any organization that has a web presence.

Steps/Explanation

1. Domain Name System: DNS is a distributed hierarchical database of information that translates hostnames to IP addresses. It is a way of mapping a website's name to its IP address.

2. DNS Hierarchy: DNS is organized in a hierarchy of DNS servers. The top of the hierarchy is the root DNS server, followed by top-level domain (TLD) servers, authoritative DNS servers, and finally, recursive DNS servers.

3. DNS Records: DNS records are used to store information about a domain name. Common types of DNS record include A records, which map a domain name to an IP address, MX records, which define the mail servers for a domain, and CNAME records, which map an alias hostname to a canonical hostname.

4. DNS Resolution: When a user types a domain name into their web browser, the browser sends a DNS request to a DNS server to resolve the domain name into an IP address. The DNS server looks up the IP address in its database, and if it's not there, it forwards the request to another DNS server.

5. AWS DNS Services: Amazon Web Services (AWS) provides several DNS services, including Amazon Route 53, a managed DNS service for resolving domain names, Amazon Simple Queue Service (SQS), a messaging service that uses DNS to identify endpoints for messages, and Amazon Elastic Load Balancing (ELB), which uses DNS to balance traffic to instances.

Examples and Use Cases

• Example: A company has a website that is hosted on an EC2 instance. They need to map their domain name to the IP address of the instance to make the website accessible. They can use Amazon Route 53 to create an A record that maps their domain name to the instance's IP address.

• Use case: An organization uses Amazon SQS to queue messages between two systems. They need to use DNS to identify the endpoints for the messages. They can use Amazon Route 53 to create CNAME records that map the endpoints' hostnames to the SQS endpoint URL.

Important Points

• DNS is a critical part of the internet infrastructure that translates domain names into IP addresses.
• DNS is organized in a hierarchy of servers, and DNS records store information about a domain name.
• DNS resolution is the process of resolving a domain name into an IP address.
• AWS provides several DNS services, including Amazon Route 53, Amazon SQS, and Amazon ELB.

Summary

DNS is a critical part of the internet infrastructure that translates domain names into IP addresses. AWS provides several DNS services, including Amazon Route 53, Amazon SQS, and Amazon ELB, that organizations can use to manage their DNS infrastructure and make their web services accessible. Understanding how DNS works and its different components is essential for any organization with a web presence.