---
title: "CNAME records explained"
description: "A CNAME makes one name an alias of another. Why it cannot sit at the root of a domain, why it cannot share a name with other records, and how to use it."
canonical_url: "https://dnsense.io/learn/cname-records-explained"
---

> Index of every page on this site: [llms.txt](https://dnsense.io/llms.txt)

A CNAME record says: this name is an alias, go and ask for that other name instead. It is how `shop.example.com` can follow a hosted shop service without you ever knowing its IP address, even when that address changes.

## How it works

The resolver asks for `shop.example.com`, finds a CNAME to `shops.example.net`, and then repeats the lookup for that name. Whatever record type it was asking for, the answer comes from the target. The target can be a CNAME again, but long chains cost lookups. Keep them short.

![shop.example.com is a CNAME to shops.example.net, which resolves to 198.51.100.7](guide-records-cname.webp)

## The target is a name, not an address

The content of a CNAME is a hostname. DNSense rejects an IP address there with "expects a hostname, not an IP address". If you have an address, you want an A or AAAA record.

## Two rules that catch people out

**A name with a CNAME cannot have any other record.** No A, no MX, no TXT beside it. The CNAME says the whole name is an alias, so anything else would contradict it. Adding a TXT record for domain verification on a name that already has a CNAME is the classic way to hit this.

**The root of the domain cannot be a CNAME.** The apex always carries NS and SOA records, so a CNAME there would break the first rule. If a service tells you to point `example.com` at a hostname, use `www` as the CNAME and redirect the bare domain, or check whether your DNS provider offers CNAME flattening or an ALIAS record. Cloudflare flattens apex CNAMEs automatically. Not every provider does.

## Mail and CNAME

An MX record must point at a name that has address records, not at a CNAME. Pointing mail at an alias works with some servers and fails with others. Use the real hostname.

## Adding one in DNSense

Click **Create record**, choose **CNAME**, enter the name (`shop`) and the target hostname (`shops.example.net`). A trailing dot is fine. The form also has a **www to apex** quick fill for the most common case.

![The New record dialog with a CNAME record for status.example.com](app-records-cname-form.webp)

Filtering the zone on CNAME shows every alias at once, which helps when you suspect one is shadowing another record.

![The zone filtered on CNAME records](app-records-cname-list.webp)

A wildcard CNAME such as `*.example.com` catches every name that has no record of its own. Handy for a platform that serves customer subdomains. Careful with it: it also catches typos.

## Sitemap

See the full [sitemap](https://dnsense.io/sitemap.md) for all pages.