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name registrar, it can lead to problems accessing your website in certain

circumstances.

'CNAME' Records

'CNAME' is short for canonical name. These records are used to define an alias for

another domain or hostname. These records are particularly useful when you have

multiple hostnames that are located on the same IP address.



Each 'CNAME' record needs to point to another valid hostname, either for the same

domain or even a completely different domain. Generally 'CNAME' records point to a

hostname that is configured in a DNS 'A' record. The format of these records is as

follows:

<HOSTNAME> IN CNAME <EXISTING HOSTNAME>

The hostname is the value preceding the '.example.com' as in the 'A' record example

and is typically something like 'www.' The existing hostname could be another

hostname for the current domain, for example 'blog.example.com.' In this case, when a

user attempts to visit 'www.example.com' they will see the content associated with

'blog.example.com.'



If the existing hostname value is set to a hostname on a different domain — for

example 'www.domain2.com' — when a user visits 'www.example.com' they will see

the same content as a user visiting 'www.example.com.'

'MX' Records

'MX' is short for Mail Exchanger. These records are used to identify the server that

handles email address for your domain name.



Each 'MX' record contains three pieces of information: the hostname, the priority and

the mail server's hostname. The format of an 'MX' record is as follows:

<HOSTNAME> IN MX <PRIORITY> <MAIL SERVER HOSTNAME>

The hostname value is the domain for which the MX record exists. This is generally set

to the value of your domain name (e.g. 'example.com.').



The priority value is a numerical value that signifies the priority of this particular MX

record — and hence the mail server. The values used for this are only important if you

have more than one mail server. The lower the value of the priority field, the higher the

priority of the mail server.



The mail server hostname is then the hostname that handles email for this domain. It

could be a google.com address if the domain uses Google Apps for email hosting, but

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