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CNAME Lookup

The CNAME Record Lookup tool is an online tool that lets you query DNS servers and get instant results.

Canonical Name, Alias, or CNAME lookups are used to determine the CNAME records associated with a domain.

Looking for easier to understand results? Use the Global DNS Checker tool.

DNS CNAME Record

CNAME records, known as Canonical Name records or alias records are used to point records to other records like A records or AAAA records. It is also possible to point them to other CNAME records, however this technique is typically not recommended as it introduces additional DNS lookups as each record in the chain is resolved.

Example CNAME record

An example CNAME record may look like the following:

Record Type Value TTL
www CNAME example.com 3600

www represents identifier of the record. CNAME records cannot be used on the root of a domain.

CNAME is the record type.

example.com is the value of the record. This will mean that the www record will resolve to the IP address of the record associated with example.com.

3600 is the TTL (time to live) of the record in seconds, this example represents 1 hour. This means that when a record has had updates made to it, then it will take 1 hour to update.

When to use CNAME records and why are they useful?

CNAME records can be used for many reasons and can be useful when maintaining your DNS zone configuration.

Some examples of why you may use CNAME records:

Easier Management - The most common use of a CNAME record is so that you only need to configure the underling IP address once. For example, the base domain name example.com would have an IP address configured as an A or AAAA record, while having CNAME records point back to this record for subdomains like www. This means that when updating the IP address, you are only required to update the address on the example.com record and the www.example.com subdomain will be updated automatically.

Service Providers - Another common case for using CNAME records is when you are using third party services. Often these third parties will ask you to use a CNAME record to point a subdomain to their domain name which allows them to change IP addresses as they need without having to ask all their customers to make the change manually. If this is the case, you may set up a CNAME record for service.example.com to point to service.service-provider.com.

Domain Verification - Often TXT records are used for domain verification, but sometimes providers also use CNAME records. Providers may generate a unique verification code as a subdomain which they ask you to point to them to prove ownership of a parent domain name. For example, you may be required to set up a CNAME record like service-XXXXXXXXXX.example.com which points to XXXXXXXXXX.verifiy.service-provider.com.

How do you perform a DNS lookup to check CNAME records?

Checking CNAME records can be done in many ways, the easiest of which is to use the online CNAME lookup tool on this page.

Alternatively, you may manually check records locally from your own system. Manually checking records is a little more involved, can be difficult to understand the results and will be different depending on your operating system.

Checking CNAME records online

To use the online CNAME lookup tool, simply enter the CNAME record into the search box and press search to perform a DNS CNAME lookup. Optionally choose a server to perform the lookup request.

Using the online tool provides many benefits over the manual tools as it can display, parse & highlight relevant information in a way that is easier to read than many command-line tools. Additionally, specifying alternative DNS resolvers to check against is as simple as choosing from a drop down without the need of knowing the IP address of these providers.

Checking CNAME records on Windows

On Windows based systems including Windows 7, Windows 10 & Windows Server, using the nslookup tool allows you to perform a DNS lookup for CNAME records using your local resolver or specify any public recursive resolver.

Using the nslookup command

Using the locally configured resolver:

nslookup
> set q=cname
> www.example.com

Using a specific resolver:

nslookup
> set q=cname
> server 1.1.1.1
> www.example.com

Checking CNAME records on Linux and Mac

On Linux and Mac systems including Mac OS X, MacOS, Ubuntu, Debian, CentOS & Red Hat, you have the choice of using either the host tool, or the more powerful dig tool to perform a DNS CNAME lookup.

Using the host command

Using the locally configured resolver:

host -t cname www.example.com

Using a specific resolver:

host -t cname www.example.com 1.1.1.1

Using the dig command

Using the locally configured resolver:

dig cname www.example.com

Using a specific resolver:

dig cname www.example.com @1.1.1.1