CNAME flattening

CNAME flattening is a technique used to handle a limitation in DNS (Domain Name System) for certain types of records, specifically CNAME records, when applied to the root domain.

Understanding CNAME Records

Normally, a CNAME record (short for “Canonical Name”) is used in DNS to point one domain name (like blog.example.com) to another domain (like example.com). This helps simplify DNS management since you can change the destination of multiple records by just updating the one they point to.

The Root Domain Issue: In DNS, the root domain, also known as the “apex” or “naked domain” (e.g., example.com without a “www”), cannot technically be assigned a CNAME record. The DNS standard doesn’t allow it because the root domain has to have an actual IP address, not a reference to another name.

How CNAME Flattening Works?

With CNAME flattening (aka ANAME record), your DNS provider helps you bypass this limitation. They essentially take the CNAME record that you want to use at the root domain and “flatten” it, so it behaves like an A record, which points directly to an IP address. Behind the scenes, your DNS provider resolves the CNAME for you, turning it into an A record, and serves that IP address to anyone who requests your domain.

Who Uses It and Why?

CNAME flattening is particularly popular with content delivery networks (CDNs) and managed DNS providers like Cloudflare or DNS Made Easy. It allows you to use a CNAME at the root domain, which is useful if you want your apex domain (example.com) to point to a dynamic or load-balanced IP address (like those used by CDNs) that can change frequently. Instead of you having to update the IP address manually each time, the DNS provider handles it.

Benefits of CNAME Flattening

• • Simplicity: You can manage DNS more flexibly and avoid manually updating IPs when they change.
  • Reliability: Your root domain can work with services (like CDNs) that require CNAMEs, even though traditional DNS wouldn’t allow it at the root level.
  • Better Performance: Flattening improves performance for sites hosted on load-balanced or distributed servers by ensuring the DNS points to the optimal IP without much delay.

In short, CNAME flattening makes it easier for your root domain to take advantage of flexible and scalable hosting solutions that otherwise wouldn’t be possible due to DNS restrictions.

CNAME Flatelling FAQs

Learn about CNAME Flattening and your options for implementing it. Find out which DNS providers support this feature and how to set it up for seamless domain management.

Does GoDaddy support CNAME flattening?

No, GoDaddy currently does not support CNAME flattening. If you need this feature, a simple solution is to use a free managed DNS provider, such as Cloudflare, which does support CNAME flattening.

Does Azure support CNAME flattening?

Yes, Azure supports CNAME flattening through its Azure DNS service by utilizing alias records. These alias records allow you to map your apex (root) domain to various Azure resources, such as Azure Front Door or Azure CDN endpoints, without the limitations of traditional CNAME records. This functionality enables seamless domain management and efficient traffic routing.

Does Namecheap support CNAME flattening?

Yes, Namecheap supports functionality similar to CNAME flattening through its ALIAS records. An ALIAS record allows you to point your root domain (apex domain) to another domain name, functioning like a CNAME record but without the limitations associated with CNAMEs at the root level. This enables you to map your root domain to another hostname while maintaining compatibility with other DNS records, such as MX or TXT records.

What other DNS Providers support CNAME flattening?

CNAME flattening is supported by several DNS providers, including:

• Cloudflare: Offers CNAME flattening, allowing the use of CNAME records at the root domain.
• Amazon Route 53: Provides Alias records, which function similarly to CNAME flattening by mapping the root domain to another domain name
• DNS Made Easy: Implements ANAME records, enabling root domain pointing to hostnames.
• CSC: Offers CNAME flattening (Alias records) as part of their DNS services.

How do I set up CNAME flattening with my DNS provider?

The setup process varies by provider. Generally, you would create a CNAME or equivalent record at the root of your domain pointing to the desired target. It’s essential to consult your DNS provider’s documentation for specific instructions.

Can CNAME flattening affect email delivery?

Improper configuration of CNAME flattening can interfere with email delivery, especially if MX records are not correctly set. It’s crucial to ensure that MX records are properly configured alongside CNAME flattening to maintain email functionality.

Is CNAME flattening the same as ANAME or ALIAS records?

While they serve similar purposes, the implementation differs. ANAME and ALIAS records are proprietary solutions offered by some DNS providers to achieve CNAME-like functionality at the root domain. CNAME flattening is a specific method employed by providers like Cloudflare to achieve this

Does CNAME flattening impact DNS resolution performance?

CNAME flattening can improve DNS resolution performance by reducing the number of lookups required to resolve a domain to its IP address. However, the actual impact depends on the DNS provider’s implementation and the specific configuration.

It’s advisable to consult your DNS provider’s documentation or support resources to confirm their support for CNAME flattening and understand the specific implementation details.