Managing CNAME Records
Table of Contents
The instructions in this article assume you’re familiar with the CNAME record format and usage.
Adding a CNAME record
To add a CNAME record
In the record editor, click and select to add a new CNAME record.
Enter the CNAME record information.
Name: the subdomain you want to create the record for, without the domain name. For example, if you want to represent
www. Leave it blank to represent the root domain
- Content: the target host name this host will point to. It must be a host name (e.g. foo.bar.com) and not a URL (e.g. http://foo.bar.com or http://foo.bar.com/foo are invalid).
As with any other DNS record, you can configure:
- TTL: the record time-to-live.
- Respond From Regions: Configure Regional Records if desired.
- Notes: Optionally include a record note.
Once you’re ready, click to confirm and create the record.
- Name: the subdomain you want to create the record for, without the domain name. For example, if you want to represent
The record is created and visible in the record list.
Updating a CNAME record
To update a CNAME record
In the record editor, search for the record and click on the pencil icon to edit it.
Update the information and click to save the record.
Removing a CNAME record
To remove a CNAME record
In the record editor, search for the record and click on the trash icon to delete it.
Confirm the dialog to delete the record.
Common CNAME errors
Cannot add a new record where a CNAME exists
To understand the error, it’s important to understand a CNAME points a whole subdomain to another name in the domain name system. If you have another record on that subdomain, you can’t add a CNAME, as that CNAME would render the other records useless. Let’s look at an example:
Let’s assume there’s an MX record on email.example.com, and you try to add a CNAME on that exact subdomain (email.example.com). If you added the CNAME, it would override the subdomain (email.example.com) and render the MX record useless, leading to a lot of potential confusion when email stops. To counter this potential confusion, the domain name system doesn’t allow other records alongside a CNAME.
You can achive a similar behavior as a CNAME with a ALIAS record. If you want a sub-domain to always resolve to the IP address of another domain, you can use a ALIAS record pointing to that domain. You should only do this if you absolutely need it, as the ALIAS record has a small amount of additional overhead when compared to A and CNAME records.