CNAME Flattening
Control D supports CNAME Flattening as a Profile Option, allowing you to simplify DNS responses by replacing long CNAME chains with a single A/AAAA record.
What Is CNAME Flattening?
When enabled, CNAME Flattening modifies upstream DNS responses that contain a chain of CNAME records ending in an A or AAAA record. Instead of returning the full chain of CNAMEs, Control D responds with a flattened answer: a single record that maps the original query name (QNAME) directly to the resolved IP address.
This feature is especially useful when:
- You want to reduce DNS resolution steps on the client side
- You're serving records to systems that don’t handle CNAME chains well
- You want more control over how DNS responses are returned
How to Enable
CNAME Flattening is configured at the profile level:
- Go to Profiles.
- Select the Profile you'd like to modify.
- In the Profile Options section, enable CNAME Flattening.
Notes
- If the upstream response does not contain a valid A/AAAA record at the end of the CNAME chain, no flattening occurs.
- Flattening is done per query; results are cached according to TTL.
Updated about 1 month ago