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What are CNAME (Canonical Name) Records?

CNAME records, also known as Alias records, point a hostname to another hostname or FQDN. They are called Alias records because they point to other records that have the mapping for that domain. When a name server looks up a domain and finds it is a CNAME record, it replaces the name with the canonical name (the target of the CNAME) and looks up the new name. In a sense, a CNAME lookup performs two queries to reach the final resolution.

CNAME records are commonly used to point multiple hostnames to a single location. This is useful when you have multiple records pointing to the same location (usually a web server at the root of a domain). If that location changes, all you have to do is change the endpoint in the record you’re pointing all those CNAME’s to. Check out some use cases here.

CNAME records can also be used to point a host name to a location that is external to the domain.


CNAME Record Fields

Related Tutorials

CNAME Record Pools
Round Robin
Weighted Round Robin
DNS Failover

Video Tutorial: How to Add, Edit, and Delete Records

ADD A CNAME RECORD

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1.Select Managed DNS and click on Domains

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2. Select the Domain Name you want to add a CNAME record to.

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3. Under the CNAME Records section, click the to add a record.

4. In this screen, you will add the record information. Follow the steps below:

A) Name: This will be the hostname for your record. It is important to note, the domain name is automatically appended to the “Name” field of the record. Note the name field is required, because a CNAME record can not be defined for the root record of the domain.
B) TTL: Edit the TTL. Time to Live is measured in seconds and is the amount of time the record will cache in resolving name servers and web browsers.
C) Record Mode: The Record Mode will be left at Standard for this tutorial. Please note, the other Record Mode options are covered in different tutorials.
D) Host: Enter the destination host you would like this CNAME record to resolve to.
E) Note: Add a helpful note with keywords so you can search for your records later.
F) Save and Close: Save your changes. Don’t forget to commit your changes.

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Information on the NX Domain feature can be found in the Disabling a Record tutorial.

5. There are two different ways you can point your CNAME to. First, you can point to an A Record within the same domain: www.example.com resolves to example.com. The tool tip at the top of the record configuration screen displays how the host will resolve.

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6. Second way is to point the CNAME record to a value external to the domain: www.example.com resolves to constellix.com. Please note, the value field must end in a dot (.) to keep the example.com domain from being appended to the end of the value. The tool tip at the top of the record configuration screen displays how the host will resolve.

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EDIT AN A RECORD

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1. Select Managed DNS and click on Domains

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2. Select the Domain Name you want to edit

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3. Under the CNAME Records section, select a record by clicking the check mark next to it, then click the icon to edit a record.

Please note, you can not edit a record that has not been committed following its creation.

4. Edit any of the record data you wish to change. Click Save and Close.

DELETE A CNAME RECORD

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1. Select Managed DNS and click on Domains

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2. Select the Domain Name you want to delete records from.

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3. Under the CNAME Records section select a record by clicking the check mark next to it, click the icon to delete a record.

Please note, you can not delete a record that has not been committed following its creation.
4. The record will now show as strike through text, and is now in the queue of changes to be committed.

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5. If this was a mistake, you can click the icon to undo the deleted record.

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