Configure DNS CNAME Record

The Problem

A service you're setting up (a subdomain, a third-party platform, an email tool) needs a CNAME record, and getting the target hostname or the record's position relative to other records wrong means it silently doesn't work.

About this problem

A CNAME record is an alias — it points one hostname to another hostname rather than directly to an IP, which is useful when the destination's IP could change without you needing to update anything. They're commonly needed for subdomains pointing at third-party services (like "shop.yourdomain.com" pointing at a hosted storefront), or for verification/tracking records a platform asks you to add.

The most common mistake is trying to add a CNAME on the root domain (@) alongside other records, which isn't allowed by the DNS spec, or pointing it at the wrong target hostname copied from an example rather than your actual account.

What's Included

• Confirming the exact target hostname the CNAME should point to
• Creating the record correctly, avoiding conflicts with other record types on the same hostname
• Checking TTL settings
• Verifying resolution and that the destination service recognises the connection

What's NOT Included

• Setting up the destination service/platform account itself
• CNAME flattening for root-domain use cases that need a provider-specific workaround
• Ongoing record management beyond this one setup

How It Works

1. Confirm the exact target hostname required, directly from the service's own documentation or dashboard, not a generic example.
2. Check the root/apex domain isn't involved, since CNAME records can't coexist with other record types on the same hostname.
3. Create the CNAME record with the correct subdomain and target.
4. Verify resolution with a DNS lookup tool once propagated.
5. Confirm with the destination service that it recognises the subdomain as correctly connected.

In practice: you buy the service, send over whatever access or details the job needs, I investigate and do the work, and you confirm it's resolved before we call it done.

Frequently Asked Questions

What is a CNAME record used for?

It makes one hostname an alias for another, so a subdomain can point to a target that's managed elsewhere and might change IP address without you needing to update anything.

Can I use a CNAME record on my root domain?

No — DNS rules don't allow a CNAME to coexist with other records (like MX) on the apex/root domain. Most DNS providers offer an ALIAS or ANAME record as a workaround if you need this behaviour at the root.

Why does my CNAME record show as not working?

Usually either the target hostname is wrong, there's a conflicting record on the same subdomain, or it hasn't finished propagating yet.

How is a CNAME different from an A record?

A CNAME points to another hostname (which then resolves further), while an A record points directly to an IP address.

Can a CNAME point to another CNAME?

Technically yes, but chaining CNAMEs adds extra DNS lookups and potential points of failure, so pointing directly at the final target is better where possible.

Will a CNAME record slow down my website?

The extra DNS lookup is negligible in practice; it won't be noticeable to visitors.