Route 53 and DNS

Question 1

What is DNS?

Answer 1

It’s a lookup for an IP Address. Think of it like a phone book

Question 2

First vs second level domain

Answer 2

In .com.au “com” is first level, “au” is second level.

Question 3

What is a registrar?

Answer 3

An authority that can assign domain names directly under top level domains.

Question 4

Who enforces uniqueness amongst domain names?

Answer 4

InterNIC, a service of ICANN. Gets registered in a central DB known as the WhoIS database

Question 5

SOA supplies what information?

Answer 5

Name of the server that supplies data
Administrator of the zone
Some troubleshooting and timeout info

Question 6

NS SF

Answer 6

Name Server

Question 7

NS Records

Answer 7

Directs traffic to the Content DNS server which contains the authoritative DNS records

Question 8

A record

Answer 8

Translate a name of domain into an IP Address

Question 9

TTL SF

Answer 9

Time to Live

Question 10

TTL

Answer 10

Time that a DNS record takes to propagate throughout the internet

Question 11

CNAME SF

Answer 11

Canonical Name

Question 12

CNAME

Answer 12

Used to resolve one domain for another eg mail.gini.co

Question 13

Alias Records

Answer 13

In AWS it maps to record sets like CNAME but for AWS services

Question 14

Key difference of Alias and CNAME

Answer 14

CNAME can’t be used for a naked record

Question 15

TF ELBs have a predefined IPv4

Answer 15

False

Question 16

Are you charged for using a CNAME?

Answer 16

Yes

Question 17

Are you charged for a alias?

Answer 17

No

Question 18

Route 53 Routing Policies list

Answer 18

Simple
Weighted
Latency
Failover
Geolocation

Question 19

Simple routing policy

Answer 19

Default AWS policy

User -> Route53 -> AWS Service

Question 20

Weighted Routing

Answer 20

Splitting traffic to a different AWS service. Can be used for A/B Testing or testing deployments

Question 21

Latency Routing

Answer 21

Route traffic based on latency (which region will give fastest response)

Question 22

Failover Routing

Answer 22

For having a primary and secondary site used by monitoring the health check