Section - Route 53

Question 1

What is DNS?

Answer 1

DNS is used to convert human-friendly domain names (e.g. http://acloud.guru) into internet protocol (IP) address (e.g. http://82.124.53.1)

Question 2

What is IPv4 Addresses?

Answer 2

• IPv4 space is a 32-bit field and has over 4 billion different addresses(4,294,967,296 to be precise)

Question 3

What is IPv6 Addresses?

Answer 3

• IPv6 was created so solve thus depletion issue and has address space of 128bits.
• There are 340,282,366,920,938,463,374,607,431,768,211,456 (or 340 undecillion) addresses.

Question 4

What is Top-Level Domain(TLD)?

Answer 4

• Top-level domain (TLD) refers to the last segment of a domain name, or the part that follows immediately after the “dot” symbol.
• For example, in the internet address: https://www.google.com, the “.com” portion is the TLD.
• These top-level domain names are controlled by the internet assigned numbers authority(IANA) in a root zone database, which is essesntially a database of all available top-level domains.

Question 5

What is a Domain Registrars?

Answer 5

• A registrar is an authority that can assign domain names directly under one or more top-level domains. These domains are registered with InterNIC, a service of ICANN, which enforces uniqueness of domain name across the internet.

Question 6

What is DNS Record Type: SOA(start of authority)?

Answer 6

The SOA record stores information about:

• The name of the server that supplied the data for the zone
• The adminstration of the zone
• The current version of the data file
• The default number of seconds for the time-tolive file on resource records

Question 7

What is DNS record Type: NS (name server)?

Answer 7

• NS records are used by top-level domain servers to direct traffic to the content DNS server that contains the authoritative DNS records.

Question 8

What is DNS record Type: A record?

Answer 8

• An A (or address) record is the fundamental type of DNS record
• The A record is used by the computer to translate the name of the domain to an IP address

Question 9

What is a TTL?

Answer 9

• The length that a DNS record is cached on either the resolving server or the user’s own local PC is equal to the value of the time to live (TTL) in seconds.
• The lower the time to live, the faster changes to DNS records take to propagate throughout the internet.

Question 10

What is DNS record Type: CNAME (Canonical name)?

Answer 10

• A CNAME (canonical name) can be used to resolve one domain name to another. For example, you may have a mobile website with the domain name http://m.mysite.com that is used when users browse to your domain name on their mobile devices.

Question 11

What is Alias records(AWS specific)?

Answer 11

• Alias records are used to map record sets in your hosted zone to load balancers, CloudFront distributions, or S3 buckets that are configured as websites.
• Alias records work like a CNAME record in that you can map one DNS name (www.example.com) to antoher “target” DNS name (elb1234.example.com)

Question 12

Alias Records VS CNAME?

Answer 12

• CNAME cannot be used for naked domain names (zone apex record). You can’t have a CNAME for http://mydomain.com
• A Record/ Alias Record can be used for a naked domain name (zone apex record)

Question 13

7 Routing Policies Available with Route 53?

Answer 13

1. Simple Routine
2. Weighted Routing
3. Latency-Based Routing
4. Failover Routing
5. Geolocation Routing
6. Geoproximity Routing (Traffic Flow only)
7. Multivalue Answer Routing

Question 14

What is AWS Route 53 Simple Routing Policy?

Answer 14

• You can only have one record with multiple IP addresses.
• If you specify multiple values in a record, Route 53 returns all values to the user in a random order.

Question 15

What is AWS Route 53 Weighted Routing Policy?

Answer 15

• Allows you to split your traffic based on different weights assigned.
• for example, you can set 10% of your traffic to go to us-east-1 and 90% to go to eu-west-1.
• Health Checks:
  
  • You can set health checks on individual record sets.
  • if a record set fails a health check, it will be removed from Route 53 until it passes the health check.
  • You can set SNS notifications to alert you about failed health checks.

Question 16

What is AWS Route 53 Failover Routing Policy?

Answer 16

• Failover routing policies are used when you want to create an active/passive set up.
• For example, you may want your primary site to be eu-west-2 and you secondary DR site in ap-southeast-2.
• Route53 will monitor the health of your primary site using a health check.

Question 17

What is AWS Route 53 Geolocation Routing Policy?

Answer 17

• Geolocation routing lets you choose where your traffic will be sent based on the geographic location of your users (i.e. the location from which DNS queries originate)

Question 18

What is AWS Route 53 Geoproximity Routing?

Answer 18

• Geoproximity routing lets Amazon Route 53 route traffic to your resources based on the geographic location of your users and your resources.
• You can also optionally choose to route more traffic or less to a given resource by specifying a value, known as bias.
• A bias expands or shrinks the size of the geographic region from which traffic is routed to a resource.
• To use geoproximity routing, you must use Route 53 traffic flow.

Question 19

What is AWS Route 53 Latency Routing Policy?

Answer 19

• To use latency-based routing, you create a latency resource record set for EC2 (or ELB) resource in each region that hosts your website.
• When Route 53 receives a query for your site, it selects the latency resource record set for the region that gives the user the lowest latency.

Question 20

What is AWS Route 53 Multivalue Answer Routing?

Answer 20

• Multivalue answer routing lets you configure Amazon Route 53 to return multiple values, such as IP addresses for your web servers in response to DNS queries.
• You can also specify multiple values for almost any record, but multivalue answer routing also lets you check the health of each resource, so Route 53 returns only values for healthy resources.