About resource records

A records

Most records are A records, which allow the greatest versatility in pointing your domain names where you want them to go. Each record consists of a hostname and an IP address.

Host field: The hostname for that particular A record. The hostname is what precedes the .domain.com in your FQDN (fully qualified domain name). For instance, on www.domain.com, www is the host. Whatever is listed here, the lookup automatically appends .domain.com to the query. A blank A record ( domain.com rather than host.domain.com) is created by putting a @ sign in the hostname field.

Common A records include: www.domain.com, ftp.domain.com, mail.domain.com, webmail.domain.com, mysql.domain.com

Points to field: This field is where you list the IP address to which the hostname should point.

CNAME records

CNAME records point to domain names instead of IP addresses. The benefit of using a CNAME record is that you can point a host to a particular domain name, then only modify the target domain name’s A records to have the change take place on both domains. This method is commonly used by those who own several top-level domains (TLD) in different versions (.com, .net, .org, etc.) of the same domain.

For example, you own domain.com and you also own domain.net, and you want the records to point to the same IP address. You can create CNAME records for the www host of domain.net that point to www.domain.com. Then, to change the www host of domain.net all you do is modify the A record of www.domain.com to point to its new IP address, and www.domain.net is automatically updated.

A common mistake when using this method is that you can accidentally modify the records for several domains when you intend to change only one. That is, you must make a note of which domains point to each other. Also, a record cannot be created with same name as an existing CNAME record.

Host field: The hostname for that particular CNAME record. The hostname should be what precedes the .domain.com in your FQDN. For instance, on www.domain.com, www is the host. Whatever is listed here, the lookup automatically appends .domain.com to the query. A blank A record (domain.com rather than host.domain.com) is created by putting a @ sign in the hostname field.

Points to field: The name that the record points to. This field must be a domain name, and not an IP address. The domain name must also end with a dot. Otherwise, when queried, the domain record will continue until it finds the next dot in the zone file.

MX records

An MX record handles the direction of mail.

Priority field: This section allows you to select your preference for an individual MX record. Records are processed in order, starting with the lowest priority and working to higher priorities. Therefore, if you have two mail servers or a mail server and a mail spooler, set the lower priority to your main mail server. Also, set a higher priority to your backup mail server or mail spooler.

Host field: You can specify a mail hostname here, but this is usually not necessary. Create a blank host (use a @ for the hostname) and point it to your mail server.

Goes to field: The address of the mail server. What is commonly done is to use the mail hostname that you created in the A record section to point to your mail server.

It is highly recommended that you point MX records to a domain name, and that the domain name (just like a CNAME record) ends with a dot.

TXT records

A TXT record generally is a record that you can query, and which returns information about a domain. These records can be used for SPF indicators, for crafting port and protocol connections, or just for returning information about a domain. They are most commonly used with the SPF protocol.

Name: The host that the TXT record can be queried by.

Value: What the TXT record returns, placed in quotations.