Route 53 and DNS Flashcards
What is DNS?
It’s a lookup for an IP Address. Think of it like a phone book
First vs second level domain
In .com.au “com” is first level, “au” is second level.
What is a registrar?
An authority that can assign domain names directly under top level domains.
Who enforces uniqueness amongst domain names?
InterNIC, a service of ICANN. Gets registered in a central DB known as the WhoIS database
SOA supplies what information?
Name of the server that supplies data
Administrator of the zone
Some troubleshooting and timeout info
NS SF
Name Server
NS Records
Directs traffic to the Content DNS server which contains the authoritative DNS records
A record
Translate a name of domain into an IP Address
TTL SF
Time to Live
TTL
Time that a DNS record takes to propagate throughout the internet
CNAME SF
Canonical Name
CNAME
Used to resolve one domain for another eg mail.gini.co
Alias Records
In AWS it maps to record sets like CNAME but for AWS services
Key difference of Alias and CNAME
CNAME can’t be used for a naked record
TF ELBs have a predefined IPv4
False
Are you charged for using a CNAME?
Yes
Are you charged for a alias?
No
Route 53 Routing Policies list
Simple Weighted Latency Failover Geolocation
Simple routing policy
Default AWS policy
User -> Route53 -> AWS Service
Weighted Routing
Splitting traffic to a different AWS service. Can be used for A/B Testing or testing deployments
Latency Routing
Route traffic based on latency (which region will give fastest response)
Failover Routing
For having a primary and secondary site used by monitoring the health check
