AEM custom domain CNAME and A-record configuration issues for author and publish tiers
Adobe Experience Manager (AEM) custom domains fail to validate, route traffic incorrectly, or display certificate warnings when CNAME or A-record DNS entries do not match the required deployment model. This issue occurs because AEMaaCS and AEM Managed Services require different DNS targets for subdomains, apex domains, CDN routing, and environment-specific endpoints. To resolve the issue, configure DNS records correctly, validate domains, and verify routing.
Description description
Environment
Adobe Experience Manager as a Cloud Service (AEMaaCS)
Issue/Symptoms
- The custom domain does not resolve to the AEM CDN and continues to point to legacy infrastructure.
- Cloud Manager cannot verify the domain because TXT or CNAME validation fails.
- Traffic routes to old infrastructure instead of the intended AEM environment.
- SSL certificate warnings appear because of hostname mismatches or missing domain mappings.
Root cause
The issue occurs because the DNS configuration is incomplete or incorrect. For AEM as a Cloud Service, subdomains require a CNAME record that points to Adobe CDN infrastructure, while apex domains require specific A-record mappings. For AEM Managed Services, DNS entries must point to the Adobe-managed ELB hostname. Because Adobe does not manage customer DNS zones, incorrect or missing DNS updates result in routing and validation failures.
Resolution resolution
Follow these steps to identify the domain type and configure the correct DNS records for the target AEM environment:
- Identify whether the domain is an apex domain or a subdomain and verify the existing DNS configuration.
- Configure a CNAME record that points to
cdn.adobeaemcloud.comfor AEM as a Cloud Service subdomains and confirm that no conflicting A-records exist. - Configure the required Fastly A-record mappings for AEM as a Cloud Service apex domains and confirm that the DNS provider supports the required record type.
- Configure a CNAME record that points to the Adobe-managed ELB hostname for AEM Managed Services domains and verify that no conflicting DNS records exist.
- Validate the domain in Cloud Manager by completing the domain verification process and confirming that the domain status displays as verified.
- Verify routing behavior by checking that requests route through the expected CDN or ELB infrastructure.
- Validate the resolution by confirming that DNS results match the expected CNAME or A-record mappings, traffic routes correctly, and domain verification remains successful.
When to escalate
- The DNS propagation does not complete after an extended propagation period.
- Cloud Manager continues to show domain verification failures after the DNS records are validated.
- Traffic continues to route to legacy infrastructure after the DNS changes become active.
- The expected ELB hostname or CDN routing behavior does not match the configured environment.