Route53 Flashcards
Explain the different DNS record types
A (address): Translates a FQDN/domain to IP
CNAME (canonical name): Translates a FQDN/domain to another FQDN
NS (Name Server): Delegates the resolution to another Name Server
ALIAS: Translates a FQDN/domain/name to another FQDN/domain/name
MX: Mail Exchange
PTR: AKA reverse lookup. It translates the IP into Domain
Important: ALIAS is preferred over CNAME
What is a top-level domain?
It is the last portion of the FQDN. It is controlled by the Internet Assigned Numbers Authority (IANA) which is a database of all top level domains.
https://www.iana.org/domains/root/db
What are the authorities that are able to register the domains?
Amazon, GoDaddy.com, etc. They use InterNIC service to register in the central database know as WhoIS
What SOA stands for?
Start Of Authority.
What are the possible routing (spells routine) policies?
Simple: A random IP of a given set is returned. In case there are multiple IPs, one is returned in random order
Weighted: Forward X percent to a target and Y to another
Latency-based: Useful to send the traffic to the user lowest latency
Failover: It used for active-passive sites. In case the primary site health check fails, the target will be changed to the secondary site
Geolocation: It will route the traffic to a set of EC2 instances based on the user location (continents/countries).
Geoproximity (Traffic Flow only): It routes the traffic considering not only the the user, but also the resource location. Its bias expands/shrinks the size of the geographic regions.
Multivalue Answer: The same as Simple record set type, but with health check for each target
What is the purpose of Route53 health check?
It allows your web service to be tested on a given frequency. You can associate this health check with the route53 record set, so in case the web service is down, it will be removed from the record set. You can also setup SNS notifications to alert if a health check is failed
How many domain names can be created within Route53?
By default, there is a limit of 50 domain names within Route53. However, this number can be increased by contacting AWS support.
