What Are CNAME Records, and What Are They Used For?
The abbreviation CNAME record stands for Canonical Name record. It is a record type used to create an alias from one domain to another in a Domain Name System. This allows developers to point to the same application hosted in the same server from multiple domains.
For example, you can point courier.com to the server IP address where the application is hosted. Then, you can use a CNAME record to point www.courier.com to courier.com. Ultimately, this allows developers to make IP changes easily since they just need to change it in a single place.
In addition, CNAME records are widely used to:
- Configure different hostnames for different services like email and FTP.
- Register the same domain in multiple countries.
- Point to the main website from other websites owned by the same company.
How Does CNAME Lookup Work?
CNAME lookup allows you to find the CNAME record for any domain or subdomain. When you perform a CNAME lookup, the tool will query the DNS servers to find if there are any CNAMEs configured to the given domain name. These CNAME lookups will be performed directly on the domain's authoritative name server to ensure all the changes are reflected without any delay.
What Does a CNAME Record Look Like?
An example CNAME record will look like below:
courier.example.com CNAME www.courier.com 3600
There are four main parts in the above CNAME record:
- Record / Domain Name
- The record's identifier and domain name.
- Type
- DNS record type. In this case, it is CNAME.
- Value
- Value of the record. CNAME record will redirect the users to this value from the domain name.
- TTL
- Time duration in seconds to expire the CNAME record.
The above CNAME record will be refreshed every 3600 seconds, and users will be redirected to www.courier.com from courier.example.com.
How to Perform CNAME Lookup Using Tools
Performing CNAME lookups using online tools is pretty straightforward. For example, let's consider the DNS checker online tool to perform a CNAME lookup.
- First, you need to open the tool.
- Then, enter the domain name and select the DNS server. Multiple DNS servers like Google, Cloudflare, and OpenDNS are available.
- Finally, click the fetch CNAME records button to display a list of CNAME records.
Frequently Asked Questions
1. How does CNAME redirect work?
CNAME record creates an alias from one domain to another in a Domain Name System. If you have linked a domain name to the IP address where your application is hosted, you can use the CNAME record to redirect users from another domain to the main domain.
For example, you can point courier.com to the server IP address and use a CNAME record to point www.courier.com to courier.com.
2. Can you have a CNAME and an A record?
No. Having a CNAME record and other records for the same name is not possible.
3. What is the difference between an A record and a CNAME?
A CNAME record is used to map a hostname to another hostname, while an A Record is used to map a hostname to one or more IP addresses.
4. Are CNAME records public?
Yes. The public can access CNAME records.
5. How do I check my CNAME record using nslookup?
You can use the nslookup online tool to check CNAME records easily. In addition, you can use your local machine to check the CNAME as follows:
- Windows -- Enter
nslookup -q=CNAME <domain name>in the command prompt. - Mac OS -- Enter
dig <domain name> CNAMEin the terminal. - Linux -- Enter
dig <domain name> CNAMEin the terminal.
6. CNAME records not showing. What should I do?
Usually, CNAME records must be visible to you without any issues since they are public. However, if you cannot see your CNAME records:
- Check if there are any CNAME records configured.
- Sometimes, it can take significant time to reflect the changes made to your DNS based on the TTL value. So, you can try after 48-72 hours.
7. Where are CNAME records stored?
CNAME records are stored in the DNS settings of your domain.
8. Can I use CNAME to redirect?
Yes. CNAME records are used to redirect users from one domain name to another.
9. How to change a CNAME record?
The steps of changing a CNAME record can be different based on your domain provider. In general, you can follow these steps to add a new CNAME record:
- Log in to your control panel.
- Go to the domain settings page and select the domain.
- Select the relevant CNAME record.
- Edit details and save the changes.
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