General information regarding DNS
DNS (Domain Name System) is a system in the Internet that translates domain names to IP addresses (IP stands for Internet Protocol) because it is easier to remember google.com than it is to remember 216.239.57.99
A domain name must have at least 2 name servers that holds the information regarding that domain.
A name server typically has the following information regarding a domain name:
Designation | Explanation |
TTL (time to live) | This sets how long time the information of this domain can be stored on the internet. This is normally 24 hours, unless you are planning a transfer to a new server. |
A-record | The IP-address that is used when no 3rd level domain is given in the URL (without the www., mail., etc.) |
Primary name server | The name of the primary server that holds the information on this domain. |
Secondary name server | The name of the secondary server that holds the information on this domain. |
Mail server 1 (MX 10) | The name of the mail server that is used to store the emails for this domain. |
Mail server 2 (MX 20) | Name of a secondary mail server that will be used as a backup if the primary mail server is unavailable (disconnected from the Internet). |
Subname | This is where the 3rd level domains are set up, if you need to have several sub domains pointing to different servers - for example sql.your-domain.com, www.your-domain.com, etc. |
Wildcard Subname | A wildcard (*) subname points to an address that should be used if a specific sub domain isn't found. |
CNAME (Canonical Name) | This is a subdomain that points to another name, not directly to an address. This enables you to have mail.your-domain.com pointing to your-domain.com. |