Route53

Question 1

What is DNS?

Answer 1

DNS, Domain Name Server, is used to convert readable web addresses into IPv4 or IPv6 addresses.

Question 2

What is IPv4?

Answer 2

IPv4 is 32 bit field first gen IP addresses w/ 4bn addresses.

Question 3

What is IPv6?

Answer 3

IPv6 is 128 bit field second gen IP addresses w/ 340 undecillion addresses meant to expand the list of available addresses for devices to use.

Question 4

What is a Top Level Domain?

Answer 4

The last section of the domain name, separated by a period, is the Top Level Domain. Ex. google.com, so “.com” is the Top Level Domain. In google.com.au, the “.au” would be the Top Level Domain.
Ex. .com, .edu, .gov

Question 5

What is the Second Level Domain?

Answer 5

The second to last section of the domain name, separated by one or more periods, is the Second Level Domain. Ex. google.com.au, so “.au” is the Top Level Domain and “.com” would be the Second Level Domain.

Question 6

What is the Internet Assigned Numbers Authority, IANA?

Answer 6

The Top Level Domain names are controlled by IANA in a database of all available top level domains.

Question 7

What is a Domain Registrar?

Answer 7

A registrar is an authority that can assign domain names directly under one or more top level domains.
Ex. Amazon, GoDaddy

Question 8

What is the WhoIS database?

Answer 8

It is the central database for each domain name that is registered with a Domain Registrar.

Question 9

What is an SOA Record?

Answer 9

Every domain addresses begins with a Start of Authority record that stores information about the name of the server that supplied the data for the zone, the administrator of the zone, the current version of the data file, and the default number of seconds for the TTL file on resource records.

Question 10

What is an NS Record?

Answer 10

The Top Level Domain server contains the web address, top level domain, and the Name Server Record name, which points to a record in the Name Server. The Name Server will point to the SOA, which contains the DNS Records.

Question 11

What is a DNS A record?

Answer 11

This is an Address record, which is used by a computer to translate the name of the domain to an IP address.
ex. google.com might translate to http://123.10.10.80

Question 12

What is TTL?

Answer 12

TTL is Time To Live. It is the length of time that a DNS record is cached on either the Resolving Server or the users own local PC. The lower the TTL, the faster changes to DNS records take to propagate throughout the internet. Typically, this is 48hrs.

Question 13

What is a CNAME?

Answer 13

CNAMEs can be used to resolve one domain name to another. For example, if you have mobile site, “m.google.com”, but in case someone types in “mobile.google.com”, you want that to resolve to “m.google.com”, instead of having two different IP addresses, you would use a CNAME to map one to the other.

Question 14

What is an Alias Record?

Answer 14

Alias records are used to map resource record sets in your hosted zone to ELBs, CloudFront distro, or S3 buckets that are configured as websites. The work like CNAMES. The key difference is that CNAMES can’t be used with naked domains, meaning without the “www”. Ex. “http://google.com”. It must an A record or an Alias.

Question 15

True or False: Elastic Load Balancers do not use IP Addresses

Answer 15

True; ELBs do not have predefined IPv45 addresses, you resolve to them using a DNS name.

Question 16

What is the difference between a CNAME and an Alias?

Answer 16

The key difference is that CNAMES can’t be used with naked domains, meaning without the “www”. Ex. “http://google.com”. It must an A record or an Alias.

Question 17

True or False: You can buy a domain name directly through AWS?

Answer 17

True; Amazon is a Domain Registrar. However, it can take up to 3 days for the domain to be registered.

Question 18

What is the Route53 Simple Routing Policy?

Answer 18

The SRP, allows only one record with one or more IP addresses. If there is more than one IP address in the A record, Route53 will randomly choose an IP to server content to the user.

Question 19

What is the Route53 Weighted Routing Policy?

Answer 19

This policy allows for multiple records splitting traffic based on different weights assigned. Ex. 50% to Ohio, 25% to Sydney, and 25% to Ireland.

Question 20

What is Route53 Latency Routing Policy?

Answer 20

This policy allows for multiple records to be set up in multiple regions so the server providing the lowest latency to the end user will be selected.

Question 21

What is Route53 Failover Routing Policy?

Answer 21

This policy allows for two records, one active server, and one secondary server. If there is a failover in the primary server, it will failover to the secondary server.

Question 22

What is Route53 Geolocation Routing Policy?

Answer 22

This policy allows multiple records which route traffic based on the end user’s geographic location. This is useful for when you want EU users to use the server designed for the EU with things like local language.

Question 23

What is Route53 Geoproximity Routing Policy?

Answer 23

This policy allows Route53 to route traffic to resources based on the geographic location of the user and of the resources. A bias allows for routing more or less traffic to different places.

Question 24

What is Route53 Multivalue Answer Policy?

Answer 24

This policy allows for multiple records, and working similarly to Simple Routing, except this allows for Health Checks.