CNAME flattening
The apex should be allowed to point at a hostname.
RFC1034 forbids a CNAME at the zone apex beside other records. Teams still need example.com to follow a CDN or application target.
Cloud DNS supports CNAME flattening. The apex can alias a hostname while the authority returns A/AAAA answers resolvers expect.
Why teams use Aptranet
How it works with Aptranet
Cloud DNS combines Anycast resolution with traffic steering and health checks. Growth and Business support TTLs as low as one second.
Apex alias to a CDN hostname
Point the root at Cloud CDN or another target without a dedicated A record you have to chase.
Other apex records still work
MX, TXT and NS can coexist with a flattened alias.
Target changes without editing A records
When the alias target moves, flattening follows it.
How to set it up
Validate your setup before production changes.
Configure your Cloud DNS zone and verify its records and routing policies. Test answers from the authoritative nameservers before changing your domain delegation.
- 1Host the zone on Cloud DNS
Apex flattening is an authoritative-zone feature.
- 2Alias the apex to the target hostname
Usually the Cloud CDN or application hostname.
- 3Keep MX and verification TXT at the apex
Flattening is not a reason to drop mail or domain proofs.
- 4Validate from more than one resolver
Confirm A/AAAA answers and that mail records remain intact.
Outcomes
What changes once the hostname is on Aptranet.
- The apex can follow a hostname
- Mail and TXT records remain at the root
- CDN cutovers do not need a frozen A record
- Subdomain CNAMEs still work as usual
Keep reading
Related pages
More DNS use cases on the same Cloud DNS footprint.
Frequently asked questions
It solves the same apex-CNAME problem: the authority returns addresses for a hostname target.
Yes. Many sites use flattening so the apex and www both reach the distribution.
The answer TTL should follow operational policy, including the one-second minimum when you need it.
Cloud DNS supports HTTPS records as well. Use them where clients benefit, alongside flattening.