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The ALIAS DNS Record

Last modified: June 20, 2024

Overview

You can use the ALIAS DNS record to resolve a domain name to the IP addresses of a different fully qualified domain name (FQDN).

Warning:
  • We strongly recommend that you do not use this function. Using the ALIAS DNS record may result in unexpected behavior, including website downtimes outside of your control, inconsistency in the handling of the record, and security vulnerabilities.
  • This record is only available if you enable access to it and use PowerDNS.

About the ALIAS DNS record

ALIAS DNS records are often used to point a domain name to an external service, such as an SaaS provider or front-end load balancer.

This usage is not recommended for a variety of reasons. This record is not RFC-compliant. For example, if the external site your alias points changes its IP address, your site will be inaccessible. Also, usage is not standardized between different implementations of this record. As a result, existing A or AAAA records may also conflict with your ALIAS record, or they may work correctly. They can also cause security issues and break DNSSEC calls. Because this record is not based off of an RFC, its behavior is not consistent between providers and it may also lose support without warning.

Enable access to the ALIAS DNS record

To enable access to the ALIAS DNS record, your system administrator must run the following command as the root user to create the touch file:

touch /etc/pdns/danger-danger-danger-server-owners-understand-the-severe-risk-and-accept-responsibility-for-any-consequences-of-using-experimental-alias-records

You must also add the following entry to the /etc/pdns/pdns.conf file, where 192.0.2.3 is your domain’s resolver address or addresses:

expand-alias=yes
resolver=192.0.2.3

Then, restart PowerDNS with the following command:

/scripts/restartsrv_pdns

This will enable access to the ALIAS DNS record in WHM’s DNS Zone Manager interface (WHM » Home » DNS Functions » DNS Zone Manager).

To enable access for the ALIAS DNS record for cPanel users, the system administrator must also add the Zone Editor (AAAA, CAA, SRV, TXT) feature to the user’s feature list in WHM’s Feature Manager interface (WHM » Home » Packages » Feature Manager).

To see if ALIAS records are enabled on your server, use WHM API 1’s is_alias_available function.

Additional Documentation