Amazon Route 53
DNS, domain routing
A DNS service: register domains, point domains to AWS resources, route by latency/geography and fail over.
- Cost$ Low
- Difficulty●●●●●
- Costs money when idle?A little
- Managed by AWS
- In examsCLF · SAA · DVA · SOA
Think of it asLike the Internet's phone book: look up a name, get the number.
Where does Route 53 fit?
A real example, step by step
- You bought the domain shop.example and want it to point to the app running behind an ALB on AWS.
- You create a hosted zone in Route 53 and add an alias record for the domain pointing to the ALB; you never need the ALB's IP.
- You build a standby copy in another region and create failover records with health checks.
- When the primary region has a problem, the health check fails and Route 53 automatically returns the standby region's address.
- When launching a new version, a weighted record sends 10% of users to it as a trial.
When to use it
✓ Use it when
Every application with a domain name.
Common uses
- Point domains to CloudFront, ALB, S3 (alias)
- Fail over between Regions using health checks
- Latency, geolocation, weighted routing (blue-green)
- Internal DNS for VPCs (private hosted zones)
Route 53, CloudFront or ELB?
| Route 53 |  CloudFront |  ELB | |
|---|---|---|---|
| What it does | DNS: turns names into addresses | CDN: caches content near users | Spreads traffic to instances in a region |
| Failover | Yes, across regions | Yes, between origins | Within a region, across AZs |
| Location-based routing | Latency, geolocation, geoproximity | Picks the nearest edge automatically | No |
| Billing | Hosted zones + queries | Data transferred + requests | Hourly + capacity used |
What does it cost?
- Pricing model: $0.50/hosted zone/month + ~$0.40/1 million queries; alias queries to AWS resources are free; health checks ~$0.50/month; domains billed yearly.
- Free tier: None (very low cost).
Forgotten hosted zones; many health checks; not using alias records, so every query is billed.
Point the zone apex (example.com) to an ALB or CloudFront → an A record alias, not a CNAME. Disaster recovery → failover routing with health checks; users in many places → latency routing; gradual rollouts → weighted routing.
Try real exam questions
1A customer is hosting their company website on a cluster of web servers that are behind a public facing load balancer. The customer also uses Amazon Route 53 to manage their public DNS. How should the customer configure the DNS zone apex record to point to the load balancer?
- ACreate an A record pointing to the IP address of the load balancer.
- BCreate a CNAME record pointing to the load balancer DNS name.
- CCreate a CNAME record aliased to the load balancer DNS name.
- DCreate an A record aliased to the load balancer DNS name.
Show answer
Correct answer: D
The zone apex can't use a CNAME. Route 53 offers an A record alias pointing to the load balancer's DNS name, which follows the load balancer even when its IPs change.
2Regarding Amazon Route 53, if your application is running on Amazon EC2 instances in two or more Amazon EC2 regions and if you have more than one Amazon EC2 instance in one or more regions, you can use [...] to route traffic to the correct region and then use [...] route traffic to instances within the region, based on probabilities that you specify.
- Aweighted-based routing; alias resource record sets.
- Blatency-based routing; weighted resource record sets.
- Cweighted-based routing; weighted resource record sets.
- Dlatency-based routing; alias resource record sets.
Show answer
Correct answer: B
Latency-based routing picks the region with the lowest latency for the user, then weighted record sets split traffic between instances in that region by the ratios you set.
Frequently asked questions
What is the difference between an alias record and a CNAME?
A CNAME points one name to another but can't be used at the zone apex (such as example.com). An alias is a Route 53 feature that can point the apex to an ALB, CloudFront or S3, and alias queries to AWS resources are free.
What routing policies does Route 53 offer?
Simple, weighted (split by percentage), latency (lowest-latency region), failover (switch to a standby when health checks fail), geolocation and geoproximity (by location), multivalue answer, and IP-based routing.
How is Route 53 priced?
Each hosted zone has a monthly fee, plus charges for DNS queries, health checks and the yearly registration fee if you buy domains through Route 53.
What do AWS exams ask about Route 53?
Picking a routing policy for a scenario (failover for disaster recovery, latency for users in many places, weighted for gradual rollouts), health checks, alias records to an ALB or CloudFront, and private hosted zones for internal names inside a VPC.