Setup

import { DirectoryListing, GlossaryTooltip, Render } from "~/components";

:::note[Availability] Subdomain setup is only available for Enterprise accounts. If you only want to create a subdomain for your site in Cloudflare, refer to Create a subdomain record. :::

Subdomain setup relies on a process known as delegation. When, in a parent domain such as example.com, an NS record is created for a subdomain blog.example.com, this means that DNS management for the subdomain can be done separately, in its own DNS zone.

    flowchart TD
      accTitle: Example of parent zone and subdomains
      A[<code>example.com</code>] --> B[<code>docs.example.com</code>]
      A[<code>example.com</code>] --> C[<code>blog.example.com</code>]
      subgraph Parent domain
        A
      end
      subgraph Subdomains
        B
        C
      end

Available setups

:::caution[Subdomain zones in partial setup are not delegated]

Subdomains using a CNAME setup (partial) represent an exception in the sense that delegation does not apply in this context. As explained in the dedicated CNAME setup (Partial) section, this setup is intended to simply proxy individual subdomains through Cloudflare. For completeness, however, this is listed as an option in this table and the how-to guide has detailed explanation on how to achieve a subdomain zone using a CNAME setup (partial). :::

This table assumes zones that are in an active status. For example, if you need to add the parent zone to Cloudflare when its child zone already exists in a CNAME setup (partial), you can convert the parent zone to a CNAME setup (partial) while it is still in pending status.

How to

Refer to the following guides to learn how to configure a subdomain setup depending on the setup used for the parent zone:

Although the how-to guides in this documentation are focused on both parent domains and subdomains existing in Cloudflare, it is also possible to achieve a subdomain setup in Cloudflare while the parent domain exists in a different DNS provider.

SSL/TLS certificates

When using subdomain setup, you should consider possible interactions between parent zone and child zone configurations that could impact SSL/TLS certificates provisioning.

If a certificate is already active on the child zone for a specific hostname (subdomain.example.com), any certificate pack containing that exact hostname in the parent zone (example.com) will fail validation.

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