Newsletter

KB Article

GP COM
DNS: The foundation for running your domain

DNS: The foundation for running your domain

The DNS settings are the most basic control function there is in relations to a domain - any errors or lack of information here affects other functions that make up an internet hotel be it mail or web. In the worst case it can render a website useless and dead, until the error is corrected and the new information spreads out into the corners of internet. Therefore changes to the DNS should not be taken lightly, and you should as a minimum have read this article through before attempting to change anything.

The different options for the DNS are:

  • TTL (Time To Live):
    This is the time that name servers on the internet can hold (cache) information on this domain without reacquiring the information from our name servers. This means that it can take up to the specified amount of seconds (typically 24 hours) before any change will be active on the entire internet.

    If you need a faster update time, if you require to change from one server IP to another, it can be set to 600 seconds (10 minutes), that means that you only need to run the old system (IP) in 10 minutes before you are sure that everybody will access the new system or IP. But be aware that the change from a TTL of 24 hours to 10 minutes will not happen after the 24 hours have passed. Therefore the procedure for a fast transfer is as follows:

    1. TTL is set to 600 seconds and the properties are stored. These changes will then take affect after 24 hours.
    2. 24 hours later (or more) you change the IP address to the new value and the properties are then stored again. This time your changes will be active in the space of 10 minutes.
    3. The website (or parts of it) are now moved to the new servers as quickly as possible.

  • A-RECORD:
    The A-RECORD is the central IP-address for the domain - if the system can't find other suitable IP addresses that respond to a query, will this A-RECORD be used.

  • Primary name server:
    This is the primary server that holds the information for the domain. You should only change this information when transferring a domain to another registrars name servers.

  • Secondary name server:
    This server must contain a copy of the information stored on the primary name server. This copying of information is done automatically by the name servers, so you need not worry about this. You should only change this information when transferring a domain to another registrars name servers.

  • Mail Server 1 (MX 10 or primary):
    The domain name or IP address of the mail server that receives mail to this domain. If the domain name or IP address of the MX-RECORD can't be found you can't receive email using this domain name - the senders mail server simply can't figure out where to deliver the emails for the domain.

  • Mail Server 2 (MX 20 or secondary):
    This is the domain name or IP address of a backup mail server, that can be used to take over the handling of email and hold them until the primary server is back online. It is possible to have up to 4 of these backup servers specified, but be aware of the fact that the servers are contacted in the show order and the first available server will be used.

  • Sub domains:
    All above mentioned settings are general and is applicable for your entire domain - but sub domains are a tool to apply specific rules to change the internet traffic. Sub domains are a unique part of a main domain:

    Main domain:

    • your-domain.com

    Sub domains:

    • www.your-domain.com
    • mail.your-domain.com
    • info.your-domain.com
    • news.your-domain.com
    • ...etc.

    A-RECORD alias
    This form for aliases directs requests to a specific IP address, like: 

    mail.your-domain.com    A-RECORD      195.41.114.8

    Wildcard alias
    The definitive simplest sub domain setting is a so called wildcard alias: 

    *.your-domain.com        A-RECORD      195.41.114.6

    This means that any request that there has no sub domain specification is directed to this IP. It is not advisable to use a CNAME record for a wildcard alias definition.

    A very commonly used setting are:

    *.your-domain.com        A-RECORD      195.41.114.6
    mail.your-domain.com     A-RECORD      195.41.114.8

    This directs all requests to 195.41.114.6, EXCEPT request for "mail.your-domain.com", which will be directed to 195.41.114.8.

    CNAME alias
    Finally we have the CNAMEs, these are widely used method of joining several sub domains to a single A-RECORD, like in the following example:

    *.your-domain.com        A-RECORD      195.41.114.6
    mail.your-domain.com     A-RECORD      195.41.114.8
    webmail.your-domain.com  CNAME         mail.your-domain.com.

    This joins the two sub domains "webmail.your-domain.com" and "mail.your-domain.com" together, so that when you need to change both of these sub domains to a new IP address you only need to change one sub domains IP. Please notice the final '.' in "mail.your-domain.com." - it is very important!

    If you wish to delete a sub domain you simply have to clear the text boxes for "sub name" and "URL/IP"

    When all changes has been entered and you have made certain that it is the correct settings, click the "Update DNS" button. If you regret or would like to start over click "Reset"


Category: Control Panel, Domain Names