Certification Authority Authorization (CAA) is a type of DNS record that allows the owner of a domain to specify which certificate authority (or authorities) are allowed to issue SSL/TLS certificates for their domain(s). This quick answer shows you how to set up CAA records on your Linode.


  1. This is an overview of almost every thing SmartWinnr offers.

  2. Select the domain you want to add the record to, or add a domain if you don’t already have one listed.

  3. Under the CAA Records section, select Add a new CAA record.

  4. Here’s an explanation of the form fields:

    Subdomain: This field indicates the domain or subdomain you want the CAA record to cover. To apply it to your entire website (, you can just leave this field blank. To limit the record’s application to a subdomain on your site, (, enter that into the form field.


    • issue - Authorize the certificate authority entered in the Value field further below to issue TLS certificates for your site.

    • issuewild - Same as above, with the exception that you were issued a wildcard certificate.

    • iodef - URL where your CA can report security policy violations to you concerning certificate issue requests.

    Value: If the issue or issuewild tag was selected above, then the value field takes the domain of your certificate issuer (for example: If the iodef tag was selected, the value field takes a contact or submission URL (http or mailto).

    TTL (Time to Live): Time in seconds that your new CAA record will be cached by Linode’s DNS name servers before being refreshed. The Default selection’s TTL is 300 seconds, which is fine for most cases. You can use dig to view the remaining time your DNS records will be cached until refreshed. Replace with your site’s domain or subdomain in the command below:

    root@debian:~# dig +nocmd +noall +answer     167 IN  A
  5. Select Save Changes when finished. The CAA record should be fully propagated within the TTL duration.