A CNAME, or Canonical Name, is a type of DNS record that acts like a nickname for your website’s address. It helps you connect one website address to another. So, when you use it, you can have more than one address for the same website.

For example, our website is “hostadvice.com.” It’s also accessible through “www.hostadvice.com” by using a CNAME. This makes it easier for people to find our website and gives us more ways to manage it.

Key Highlights

• A CNAME is like an alias for a website address that connects it to another domain name
• Using a CNAME can make website management easier, but having multiple domain names associated with it can cause confusion
• To create a CNAME, access your domain registrar’s DNS settings and create a new record linking your domain name to another domain name
• Knowing what a CNAME is helps you efficiently manage your website and improve user experience

What Is a CNAME?

A CNAME, also known as a Canonical Name, is a type of DNS record that acts as an alias for a website address. It connects it to another domain name and allows you to use multiple domain names for the same website.

It’s like having two doors to enter the same room, such as having “example.com” and creating a CNAME record for “www.example.com” that points to the same website. This way, users can reach the same destination using different domain names.

How Does a CNAME Work?

A CNAME works by providing an alternate name for a domain name. This helps ensure that the user reaches the correct website. Here’s how it works:

• The user types in a domain name in their browser
• The browser sends a request to the DNS resolver to find the IP address associated with that domain name
• The DNS resolver checks the DNS records for that domain, starting with the CNAME record
• If a CNAME record exists, the DNS resolver follows the link to the target domain and searches for the IP address
• The DNS resolver returns the IP address to the browser
• The browser sends a request to the server at the IP address, and the server responds by sending the website to the browser, ensuring the user reaches the correct website

What Are the Format and Components of CNAME?

A CNAME has a simple format that’s typically shown like this: alias.example.com. It includes the following:

• Alias Domain Name: This is the domain name you want to link to another domain. It’s the starting point of the CNAME.
• Record Type: In this case, the record type is CNAME, which indicates that the record is a Canonical Name record.
• Target Domain Name: This is the domain name you want to connect the alias domain to. It’s the destination point for the CNAME record.

What Are the Benefits of Using a CNAME?

A CNAME record is a powerful DNS tool that can simplify managing websites and online services. Here are some key benefits of using it:

1. Simplified Management

With CNAME records, you can connect multiple domain names to a single IP address, which makes it easier to manage your online resources in one place. This eliminates the need to update the IP address for each domain name separately, saving you time and effort.

2. Subdomain Creation

If you’re a website owner, you can use CNAME records to create subdomains (like blog.example.com) that point to the main domain (example.com). This lets you manage different sections of your website and saves you the hassle of changing IP addresses for each subdomain, making it easier to manage your website.

3. Load Balancing

A CNAME improves website performance and reliability by letting you create multiple CNAME records that point to different server addresses. This can be used for load balancing to ensure your website remains accessible even if one server is down. This is important because downtime can be costly, with businesses losing between $2,300 to $9,000 per minute.

4. Domain Aliasing

A CNAME lets you use different domain names for the same website or service, which can be helpful for branding or marketing purposes. For example, you could use it to point “store.example.com” to “shop.example.com,” which could make it easier for customers to remember and find your online store.

What Are the Drawbacks and Limitations of a CNAME?

A CNAME offers benefits, but there are challenges and restrictions to keep in mind when using it. These include:

1. Slower Lookups

CNAME records can slow down DNS lookups because the resolver needs to follow the CNAME record to find the target domain name and then look up the IP address. Even a delay of one second in page load time can lead to a 7% drop in conversions, so it’s crucial to monitor website performance and optimize DNS lookups to minimize any potential delays.

2. Conflicts with Other Records

CNAME records can’t be used with other records for the same alias domain name, like having both an A Record and a CNAME record for example.com. This is because DNS rules don’t allow CNAME records to exist with other data.

3. No IP Address Link

CNAME records only link domain names, not IP addresses. Use A Records (IPv4) or AAAA Records (IPv6) to link domain names to IP addresses.

4. Not for Root Domains

CNAME records shouldn’t be used for root domains like example.com because they only link the domain name to another domain name, not to an IP address directly. This can slow down the website’s load time and cause DNS lookup issues. Instead, use A Records or AAAA Records to connect root domains directly to IP addresses.

CNAME vs. Other DNS Record Types

When managing domain names, it’s essential to understand the different roles of DNS record types. Let’s compare CNAME records to other common DNS record types:

CNAME vs. A Records

CNAME records let you link one domain name to another, while A records connect a domain name directly to an IPv4 address. In other words, CNAME records make domain management easier, while A records are useful for directly mapping domain names to IP addresses.

CNAME vs. AAAA Records

AAAA records are similar to A records but connect a domain name to an IPv6 address instead. On the other hand, CNAME records link domain names without using IP addresses.

CNAME vs. MX Records

MX records manage email routing by identifying the mail server responsible for accepting incoming email messages for a domain. CNAME records shouldn’t be used for email routing and with MX records.

CNAME vs. NS Records

NS records delegate a domain or subdomain to a set of name servers, while CNAME records only link domain names and don’t handle name server delegation. Choose the right type of record based on your specific needs.

How to Set Up a CNAME

Setting up a CNAME record is essential in managing domain names. Here’s how to do this using your domain registrar or DNS provider:

1. Choose Your Domain Registrar or DNS Provider

Select the domain registrar or DNS provider where your domain is hosted. This is the platform you will use to create the CNAME record.

2. Locate DNS Management

Log in to your account and go to the domain management or DNS settings section. Look for the option to manage DNS records for the domain you want to create a CNAME record for.

3. Add a New CNAME Record

Find the option to add a new DNS record, and select “CNAME” as the record type.

4. Enter Alias and Target Domain

Input the alias domain (the domain you want to link) and the target domain (the domain you want the alias to point to). For example, if you want blog.example.com to point to example.com, enter blog as the alias and example.com as the target domain.

5. Save Changes

Save your changes and wait for the DNS changes to take effect. This process can take anywhere from a few minutes to 48 hours. Once done, your CNAME record should be active and functioning as intended.

How to Modify and Delete a CNAME

If you need to modify or delete a CNAME record, you can do so using your domain registrar or DNS provider. Follow these steps to manage your CNAME records:

1. Access Your Domain Registrar or DNS Provider

Log in to the platform where your domain is hosted, which is the domain registrar or DNS provider you’re using.

2. Find DNS Management

Go to the domain management or DNS settings section, and look for the DNS records for the domain you want to modify or delete a CNAME record for.

3. Modify a CNAME Record

To modify a CNAME record, find the specific record you want to change, click the edit or modify button, and update the alias or target domain as needed. Save your changes and allow time for the DNS updates to be applied to all servers.

4. Delete a CNAME Record

To delete a CNAME record, locate the specific record you want to remove and click the delete or remove button. Confirm the deletion, and the CNAME record will be removed.

What Are the Common Issues with CNAME Records?

CNAME records are helpful for managing domain names, but they can cause issues if not set up or managed correctly. Here are their common issues and how to avoid them:

• CNAME Chains

Long CNAME chains can slow down DNS resolution and cause problems with loading websites. To avoid these issues, it’s best to keep the CNAME chain as short as possible.

• Record Conflicts

Conflicting records for the same domain name can cause problems with DNS resolution, which can result in errors. For example, having both a CNAME record and an A record for the same domain name can lead to unpredictable results.

To avoid these issues, understand the purpose of each record type and make sure there are no conflicts between them. You should also regularly review your DNS records to ensure they’re up-to-date.

• Subdomain CNAMEs

Using CNAME records for subdomains that already have other record types can cause DNS resolution problems. In fact, DNS resolver software may not always follow CNAME chains, especially when they include other record types. Avoid this issue by only using CNAME records for subdomains without any other record types.

• DNS Propagation

CNAME record changes may take 24-48 hours to propagate across the internet. During this time, it’s important to monitor the DNS propagation process and be patient while waiting for changes to take effect.

What Are the Best Practices for Managing a CNAME?

Properly managing your CNAME records is important for maintaining a reliable online presence. Here are some best practices to keep in mind:

• Limit CNAME chaining to avoid slower DNS resolution and resolution failures. Shorter chains lead to better performance.
• Use CNAME records for subdomains and A or AAAA records for root domains to optimize DNS lookup speed.
• Avoid record conflicts with other record types such as A, AAAA, or MX records for the same alias domain name. This can cause errors and impact DNS resolution.
• Check and update your CNAME records regularly to make sure they’re correct and useful. Removing or updating old and unused records helps keep your domain management at its best.
• Check the progress of DNS changes after modifying CNAME records. It may take several minutes up to two days for the changes to take effect.

Conclusion

A CNAME is a DNS record that maps one domain name to another. This guide has covered what a CNAME is, how it works, its format and components, benefits and drawbacks, and how it compares to other DNS record types. It has also discussed how to set up, modify, and delete a CNAME, as well as best practices for managing it and common issues to avoid.

Knowing how to use CNAME records correctly is crucial in managing your domain names and DNS settings. By understanding their benefits and limitations and how to properly set them up, you can optimize your domain management and ensure a smooth user experience for your website or application.

Next Steps: What Now?

• Learn how and when to use CNAME records
• See the top 5 website builder providers
• Discover the top 9 web hosting providers

Further Reading (Useful Resources)

• Managing DNS for Web Hosting: The Ultimate Guide
• How to Use DNS tools for Web Hosting