Route 53 Flashcards
What is DNS?
DNS is used to convert human-friendly domain names (http://acloud.guru) into an Internet Protocol (IP) address (http://82.124.53.1).
What are the two common forms of IP addresses that Route 53 supports?
IPv4 and IPv6
What is an IPv4 IP address?
The IPv4 space is a 32-bit field and has over 4 billion different addresses (4,294,967,296)
What is an IPv6 address?
The IPv6 space is a 128-bit field that has over 340 undecillion different addresses
What is a top-level domain name?
The last word in a domain name (e.g. “com” of google.com, “guru” of acloud.guru)
What is the second-level domain name?
The second to last work in a domain name and is optional (e.g. “co” of bbc.co.uk)
Who controls the top-level domain names?
The Internet Assigned Numbers Authority (IANA) in a root zone database (http://www.iana.org/domains/root/db)
What is a domain registrar?
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 names across the internet.
Where do domain names get registered?
With InterNIC, a service of ICANN, which enforces uniqueness of domain names across the internet, and are stored in the WHOIS database
What does the SOA record in DNS store?
It is the “Start of Authority” record and it stores:
1. The name of the server that supplied the data for the zone
2. The administrator of the zone
3. The current version of the data file
4. The default number of seconds for the time-to-live file on resource records
What does the NS records in DNS used for?
It is the “Name Server” record and they are used by top-level domain servers to direct traffic to the content DNS server that contains the authoritative DNS records.
What is an A record in DNS?
An A (or Address) record is the fundamental type of DNS record, and is used by a computer to translate the name of the domain into an IP address.
What is TTL in DNS?
The length that a DNS record is cached on either the revolving server or the user’s own local PC is equal to the value of the TTL (time to live) in seconds.
The lower the time to live, the faster changes to DNS records take to propagate throughout the internet.
What is a CNAME record in DNS?
A CNAME (canonical name) record can be used to resolve one domain from another. For example, you may have a mobile website with the domain name http://m.acloud.guru and a CNAME can be used to point http://mobile.acloud.guru to http://m.acloud.guru.
What are Alias records in DNS?
Alias records are used to map resource record sets in your hosted zone to load balancers, CloudFront distributions, or S3 buckets that are configured as websites.
Alias records work as CNAME records in that you can map one DNS name (www.example.com) to another target DNS name (elb1234.elb.amazonaws.com).
Only a concept in AWS.
They can be used for naked domain names (zone apex records, like http://acloud.guru).