Understanding Alias Records in Amazon Route 53: Choosing Between Alias and Non-Alias Records
Table of contents
Introduction Amazon Route 53 offers a specialized feature called alias records, providing a Route 53-specific extension to DNS capabilities. Alias records enable the routing of traffic to various AWS resources, offering unique advantages over traditional CNAME records.
Key Features of Alias Records Alias records facilitate routing traffic to selected AWS resources, including:
Amazon S3 buckets
CloudFront distributions
Another record within the same Route 53 hosted zone
Comparison with CNAME Records
| Aspect | Alias Records | CNAME Records |
| Resources | Limited to selected AWS resources | Can redirect DNS queries to any DNS record |
| Zone Apex | Can be created at the zone apex | Cannot be created for the zone apex |
| Pricing | No charge for alias queries to AWS resources | Charges incurred for CNAME queries |
| DNS Query Response | Based on specified name and type in query | Redirects queries for a record name regardless of type |
Benefits of Alias Records
Automatic adaptation to changes in associated AWS resources
Simplified management with automatic TTL handling by Route 53
Considerations
Limited to selected AWS resources within Route 53 hosted zones
Pricing implications for DNS queries, particularly with CNAME records redirecting to Route 53 hosted zones
DNS query response based on specified name and type in the query
Visibility in Dig or Nslookup Queries Alias records appear as the specified record type (e.g., A or AAAA) with the alias property visible only in the Route 53 console or in programmatic requests.
Conclusion Understanding the distinctions between alias and CNAME records is crucial for effectively leveraging Route 53's capabilities. By considering the advantages and considerations of each record type, users can make informed decisions tailored to their specific requirements, ensuring efficient and reliable DNS routing within AWS environments.