Hosted Zones

Public Hosted Zones
Private Hosted Zones

Public Hosted Zone

Contains records that specify how to route traffic on the Internet.

Private Hosted Zones

Contains records that specify how you route traffic within one or more VPCs (private domain names).

CNAME Vs Alias

CNAME

Points a hostname to any other hostname(only for non-root domain)

Alias

Points a hostname to an AWS Resources(work for both non-root domain and root domain)

Health check

• monitor an endpoint
• monitor other health check (calculated heath check)
• monitor CloudWatch Alarms (to monitor the private vpc resources. By setting cloudwatch metric to check the resource and health check the alarm state)

Alias Record Targets

• Elastic Load Balancer
• API Gateway
• Cloudfront
• Beanstalk
• S3 Websites
• VPC Interface endpoints
• Global Accelerator
• Route 53 records
  Cannot set Alias record for EC2 DNS name

Routing Policies

• Simple
• Weighted
• Failover
• Latency based
• Geolocation
• Multi-Value Answer
• Geoproximity

Simple Routing

Normally, route traffic to a single resource.
Can specify multiple values and if multiple values are returned, client randomly pickup a value.
If we set for alias record, only one aws resource can be set.

Weighted Routing

Need to assign each record a relative weight
traffic(%)= weight for a specific record/ sum of all the weights for all records
Must have same name and type.
Can be associated with health checks.
If all the resources' weights are set to zero, they will be returned equally

Latency Based Routing

Redirect to the resource that has the least latency and closes to client.
Can be associated with health checks (failover capability is available)

Failover Routing

Health check is mandatory.
There will be primary and secondary. If the health check failed on the primary, routet53 will route to secondary.

Geolocation

Routing based on user location.

Geoproximity

Route based on geolocation of the user and resources.
Ability to shift more traffic to resources based on defined bias.
1 to 99 to expand
-1 to -99 to shrink

IP-Based routing

Routing based on clients' IP

Multi-Value

Use to route traffic to multiple resources.
Can be setup up to 8 resources.

Route 53 - Resolver Endpoints

Inbound Endpoint - Resolves domain names for AWS resources and on premises data center (On premises and aws are connected with VPN or DX connection)

Outbound Endpoint - Forwards DNS queries to on premises DNS resolvers
(On premises and aws are connected with VPN or DX connection)