Route 53

Question 1

DNS

Answer 1

Domain Name System which translates the human friendly hostnmaes into the machine IP addresses

www.google.com=>172.217.18.36

DNS is the backbone of the internet

Question 2

Domain Registrar

Answer 2

Amazon Route 53, GoDaddy,NS

Question 3

DNS Records

Answer 3

A, AAAA, CNAME, NS

Question 4

Zone File

Answer 4

contains DNS recors

Question 5

Name Server

Answer 5

resolves DNS queries (authoritative or non-authoritative)

Question 5

Top Level Domain (TLD)

Answer 5

.com, .us, .gov, .org

Question 6

Second Level Domain (SLD

Answer 6

amazon.com, google.com

Question 7

Route 53

Answer 7

Highly available, scalable, fully managed and authoritative DNS

Authoritative = the customer (you) can update the DNS records

Domain Registrar as well

The only AWS service which provides 100% availability SLA

Question 8

Route 53 records

Answer 8

how you want to route traffic for a domain

Each record contains:
1. Domain/Subdomain Name- e.g example.com
2. Record Type- e.g. A or AAAA
3. Value- e.g 12.34.56.78
4.Routing Policy- how Route 53 responds to queries
5. TTL- amount of time the record cached at DNS Resolvers.

Question 9

DNS Record Types that Route 53 SUpports

Answer 9

A/ AAAA/ CNAME/ NS

Question 10

A

Answer 10

maps a hostname to Ipv4 address

Question 11

AAAA

Answer 11

maps a hostname to IPv6 address

Question 12

CNAME

Answer 12

maps a hostname to another hostname

The target is a domain name which must have an A or AAAA record.

Question 13

NS

Answer 13

Name Servers for the Hosted Zone. They are the DNS names or IP addresses of the servers that can respond to the DNS queries for your hosted Zone.

Question 14

Hosted Zones

Answer 14

A container for records that define how to route traffic to a domain and its subdomains.

Question 15

Public Hosted Zones

Answer 15

contains records that specify how to route traffic on the internet (public domain names)

$0.50/month per hosted zone.

Question 16

Private Hosted ZOnes

Answer 16

contain records that specify how you route traffic with one or more VPCs (private domain names)

URLs you can only access within your private corporate network.

Question 17

TTL

Answer 17

Time To Live

TTL is saying client please cache this result for duration of the TTL.

purpose is we don’t want to query the DNS too often because we don’t expect records to change a lot, using response we have the client can access the web server and do http request and responses.

Question 18

CNAME

Answer 18

Points a hostname to any other hostname (app.mydomain.com =>blabla.anything.com)

only for non root domain (aka something.mydomain.com

Question 19

Alias

Answer 19

Points a hostname to an AWS resource (app.mydomain.com => blabla.amazonaws.com)

works for root domain and non root domain (aka my domain.com)

free of charge and have native health check

Always typeA/AAAA

Question 20

Alias Record Targets

Answer 20

ELBs

CloudFront Distributions

API Gateway

Elastic Beanstalk environments

S3 websites

VPC Interface Endpoints

Global Accelerator accelerator

Route 53 record in the same hosted zone

you cannot set an alias record for an EC2 DNS name

Question 21

Routing Policy

Answer 21

Define how Route 53 responds to DNS queries

DNS does not route any traffic, it only responds to the DNS queries.

Question 22

Simple Routing Policies

Answer 22

Typically, route traffic to a single resource

Can’t be associated with Health Checks

Question 23

Weighted Routing Policies

Answer 23

control the % of the requests that go to each specific resource

Assign each record a relative weight.

DNS record must have same name and type.

use case: load balancing between regions, testing new application versions.

Assign a weight of 0 to a record to stop sending traffic to a resource.

If all records have a weight of 0, then all records will be returned equally.

Question 24

Routing Policy Latency Based

Answer 24

Redirect to the resource that has the least latency close to us

latency is based on traffic between users and AWS regions