Route 53

Question 1

What is DNS?

Answer 1

Translates human friendly hostnames into machine IP addresses

Question 2

Amazon Route 53

Answer 2

Scalable and authoritative (customer can update DNS records) DNS

Question 3

Route 53 supports the following DNS record types

Answer 3

• A
• AAAA
• CNAME
• NS

Question 4

A record type

Answer 4

maps hostname to IPv4

Question 5

AAAA record type

Answer 5

maps hostname to IPv6

Question 6

CNAME record type

Answer 6

Target is a domain name which must have an A or AAAA record

Question 7

NS record type

Answer 7

name servers for hosted zone (control how traffic is routed for a domain)

Question 8

Route 53 hosted zones

Answer 8

Container for records that define how to route traffic to domain and its subdomains

Question 9

What does high records TTL mean?

Answer 9

Less traffic on Route 53 but possibly outdated records

Question 10

What does low records TTL mean?

Answer 10

More traffic on Route 53 ($$) but records are outdated for less time and it is easy to change records

Question 11

What is a CNAME record?

Answer 11

Points a hostname to any other hostname (only for root domain)

Question 12

What is a Route 53 alias?

Answer 12

Points a hostname to an AWS resource (works for root domain and non root domain), free of charge, native health check

Question 13

Can you set TTL on alias record?

Answer 13

no

Question 14

Simple routing policy

Answer 14

Route traffic to a single resource, can specify multiple values in the same record (random one is chosen by the client)

Question 15

Weighted routing policy

Answer 15

Control the percentage of requests that go to each specific resource (used for load balancing between regions, testing new application versions)

Question 16

Latency based routing policy

Answer 16

Redirect to the resources that has the least latency close to us (based on traffic between users and AWS regions)

Question 17

Route 53 calculated health checks

Answer 17

Combine results of multiple health checks into a single health check

Question 18

Geolocation routing policy

Answer 18

Routing based on user location

Question 19

Geoproximity routing policy

Answer 19

Route traffic to resources based on location of users and resources, can give bias to particular regions, can shift traffic to a particular region by increasing bias

Question 20

IP based routing policy

Answer 20

Routing based on client IP addresses, provide list of CIDRs for clients and the corresponding endpoints

Question 21

Multi value routing policy

Answer 21

Use when routing traffic to multiple resources, but not a substitute for having an ELB as it is client side load balancing

Question 22

Can you use route 53 as DNS service provider if you buy your domain on 3rd party registrar?

Answer 22

Yes - create hosted zone in route 53 and update NS records on 3rd party website to use route 53 name serveres

Question 23

What is VPC?

Answer 23

Private network to deploy your resources

Question 24

What are subnets?

Answer 24

Allow you to partition your network inside the VPC (on AZ level)

Question 25

What does internet gateway do?

Answer 25

Allows VPC instance to connect with the internet

Question 26

What does a NAT Gateway (AWS) or NAT instance do?

Answer 26

Allow instances in Private Subnets to access the internet while remaining private

Question 27

What is a NACL / Network ACL?

Answer 27

Firewall which controls traffic from and to a subnet (can have ALLOW and DENY rules, rules only include IP addresses)

Question 28

What is VPC peering?

Answer 28

Connect two VPC with non overlapping IP ranges (not transitive)

Question 29

What are VPC endpoints for?

Answer 29

Provide private access to AWS services within VPC