Does not actually route or forward traffic (like an ALB) but only responds to queries of a particular domain.
Allows for Public Hosted Zones or Private Hosted Zones.
Contains records with the following attributes:
Name (Domain Name)
Type
Value
TTL
Routing Policy
DNS Record Types
SOA (Start of Authority))
Contains administrative information
NS (Name Server)
Identify the name server and its domain
A record
The IPv4 address of a given host
AAAA
The IPv6 address of a given host
CNAME
Maps one domain name to another
Can’t be used for naked domain
Alias
An AWS extension that points to an AWS resource e.g. CloudFront.
Can be used with naked domain
Does not require TTL
Routing Policies
Simple
Can have multiple values and all the values will be returned to the client.
Client will choose only one if it received multiple values
Can only specify one value if it is an alias
No health check.
Weighted
Calculates the portion(percentage) of the traffic by dividing the weight of the record with the combined weight of the same domain.
Can have health check.
Latency
Choose the lowest latency relative to the location of the client to AWS so the resource must be in AWS resource.
Must specify the region of the resource. This, and the location of the user, is used to calculate latency. AWS uses its own database to determine the latency of the IP address (https://www.youtube.com/watch?v=PVBC1gb78r8&t=1963s @33:09)
Can have health check
Failover
Must specify a Primary and Secondary resource.
Traffic is always routed to Primary unless it is not considered healthy. In which case, the Secondary will handle all traffic.
Must always perform health check.
Geolocation
Route traffic based on where the DNS query originated. Latency is not considered. Can use continent or country or states if in US.
Should have a default record else Route 53 will reply with No Answer.
Can have health check.
Geoproximity
Based on the user and resource location.
By default, returns the endpoint which is of minimal distance from the client.
This can be skewed by changing the bias for a particular location.
Configured from ‘Traffic Policy’.
Multi-value
Similar to Simple where multiple values can be specified.
But unlike Simple routing, a health check is performed on every endpoint.
