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Amazon Route 53 & DNS Routing

AWS DNS from hosted zones and records to alias targets, health checks and routing policies for latency, failover, weighted and location-aware traffic decisions.

CLF-C02

Visual overview

DNS DECISION LAYERResolve a name using the policy that matches the traffic-management goal
01DNS queryClient asks for a name
02Hosted zoneFind matching record
03Routing policyWeighted · latency · failover…
04DNS answerClient then connects to target
SimpleWeightedLatencyFailoverGeolocationMultivalue
Route 53 chooses DNS answers. TTL controls DNS caching; the resulting application traffic still depends on ordinary network routing and security.
AWS SERVICE MAPResolve, then connect

DNS chooses an answer; the client then opens a separate connection to the selected application endpoint.

Route 53DNS policy
CloudFrontEdge target
Load balancerRegional target
EXAM-RELEVANT MECHANICS

Technical reference

Route 53 selects DNS answers; TTL and routing policy determine how those answers behave.

Hosted zonePublic / private

Public zones answer internet DNS; private zones serve associated VPC DNS use cases.

TTLResolver cache time

A higher TTL can reduce DNS queries but slows how quickly cached answers expire.

AliasAWS-aware target

Alias records can target supported AWS resources and work in zone-apex cases where a CNAME cannot.

PoliciesSimple · weighted · latency · failover…

Choose the policy from the desired DNS decision, not from a generic ranking.

DNS turns names into routable answers

Amazon Route 53 is a highly available, scalable Domain Name System (DNS) web service. It can register domains, host DNS records and perform health-aware traffic routing. A hosted zone contains the records for a DNS namespace: a public hosted zone answers internet DNS queries, while a private hosted zone provides DNS information to associated VPCs according to Route 53 Resolver behavior.

DNS does not forward the application packet itself. A client asks DNS to resolve a name, receives an answer such as an IP address or target record, then starts a separate network connection to that destination. This distinction explains why a healthy DNS answer cannot fix a missing VPC route or blocked security group, and why DNS TTL affects how long resolvers may cache an answer rather than how long an application connection remains open.

Routing policies express the kind of DNS decision you need

Route 53 routing policies include simple routing for straightforward records, weighted routing for distributing answers by configured weight, latency-based routing for choosing the AWS Region expected to provide lower latency, failover routing for active/passive patterns, geolocation and geoproximity options for location-aware decisions, IP-based routing and multivalue-answer routing. The correct policy follows the decision requirement rather than a general ranking.

Health checks can be combined with supported routing patterns so unhealthy endpoints stop being returned as expected by the policy. Weighted routing is useful for gradual traffic shifts or controlled splits; latency routing targets user experience across Regions; failover routing expresses primary/secondary intent. Remember that DNS caching means a change is not necessarily observed by every resolver instantaneously.

Alias records are AWS-aware DNS records

Route 53 alias records can route queries to selected AWS resources such as CloudFront distributions and Elastic Load Balancing load balancers. Alias behavior is integrated with AWS resource targets and differs from an ordinary CNAME record. One exam-relevant advantage is that alias records can be used at the zone apex where a CNAME cannot normally be used, subject to supported target behavior.

Route 53 costs are driven by dimensions such as hosted zones, DNS queries and optional features such as health checks or traffic flow capabilities according to current pricing. Because DNS sits on every user request path while its records change relatively infrequently, carefully selected TTLs balance resolver caching against how quickly answer changes should propagate.

Key takeaways

  1. 01

    Route 53 provides authoritative DNS, domain registration and health-aware DNS routing capabilities.

  2. 02

    Routing policies solve different decisions: weighted, latency, failover and location-aware policies are not interchangeable.

  3. 03

    DNS returns an answer; it does not create the VPC route or authorize the resulting application traffic.

  4. 04

    Alias records integrate Route 53 with supported AWS targets and can solve zone-apex routing cases.

Official AWS sources

Use these primary AWS resources for the source material behind this article and for deeper reference.