Content Delivery and Domain Name System (DNS)

Question 1

What is Route 53?

Answer 1

Simplified Defintion:
Route 53 is where you configure and manage web domains for websites or applications you host on AWS.

AWS Definition:
Route 53 has three main functions:

1. Domain Registration: Route 53 lets you register domain names such as example.com.
2. Domain Name System (DNS) Service: Route 53 translates friendly domain names like www.example.com into IP addresses like 192.0.2.1. Route 53 responds to DNS queries using a global network of authoritative DNS servers, which reduces latency.
3. Health Checking: Route 53 sends automated requests over the internet to your application to verify that it’s reachable, available, and functional.

Question 2

How does DNS route traffic to your web application (the flow)?

Answer 2

1. User types in web address (www.example.com) to computer
2. Goes to DNS resolver
3. Goes to DNS root name server
4. Goes to name server for .com TLD
5. Goes to Route 53 name server
6. Route 53 name server gives IP address (192.0.2.44) to DNS resolver which sends it back to the computer.
7. Computer uses IP address to go to Web Server for www.example.com or 192.0.2.44.
8. Web page for www.example.com is shown to end user.

Question 3

What is DNS server?

Answer 3

A database of website domains and their corresponding IP addresses. Web browsers send their dowmain names and it returns the correct IP Address so they can find the server on the internet.

Website admins must register their web doamin and IP address with DNS providers if they want users to find their websit without knowing the IP address.

Question 4

What is CloudFront?

Answer 4

Simplified Definition:
CloudFront is a content delivery network (CDN) that allows you to store (cache) your content at “edge locations” located all around the world. This allows your customers to access your content more quickly (and also provides additional security - especially against DDoS attacks).

Points of Presence (pink dots) on the AWS global infrastructure map.

AWS Defintion:
CloudFront is a global content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to your viewers with low latency and high transfer spedds. CouldFront is integrated with AWS - both physical locations that are directly connected ot the AWS global infranstructure, as well as software that works seamlessly with services including AWS Shield for DDoS mitigation, S3, Elastic Load Blancing, or EC2 as origins for your applications, and Lambda to run custome code close to your viewers.

Question 5

What is a DDoS Attack?

Answer 5

Distributed Denial of Service attack - typically thousands of computers that try to overload a server. Server crashes or becomes super slow.

CloudFront edge locations help to prevent DDoS attacks by redistributing traffic to an edge location where data has been cached.

Question 6

What if the data a user is requesting is not cached at a CloudFront edge location?

Answer 6

The user will be directed to a CloudFront “Origin” which can be an ELB, EC2, or S3. Where ever the data is stored. It grabs the data and pulls it to the edge location which then sends to the user.

Question 7

What does CDN stand for and what is an example of it?

Answer 7

Content Delivery Network. CloudFront is an example.

Question 8

Which AWS service would you use to purchase a domain name?

Answer 8

Route 53

Question 9

Which AWS Service allows you to configure a DNS record set?

Answer 9

Route 53

Question 10

Which AWS service is used to manage DNS?

Answer 10

Route 53

Question 11

Which of these AWS services does CloudFront integrate with for DDoS protection?

Answer 11

AWS Shield