What is a Wildcard DNS?

Discussion in 'Site & Server Administration' started by thapame, Nov 7, 2007.

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  1. #1
    A wildcard DNS record is a catch all record in a DNS zone that will match all non-existent requests for a domain name. Just like whenever you setup “catch all” or “nobody” email account, that will act as a “catch-all” account for any non-specified or misspelled username, as long as the domain name is correct. Then you will be able to retrieve these messages at the mail account you specify. So Wildcard DNS is just like that but is used on domain aliases of host name. On another wold you can also call it as Catch all Sub domains.

    For example I have setup Wildcard DNS on domain zeroarticles.info, I have not created any subdomain/aliases on that domain. So if someone visits profile.zeroarticles.info the wildcard will forward that user to www.zeroarticles.info, same thing applied on test.zeroarticles.info, abc.profile.zeroarticles.info

    That means everything which comes as domain aliases will be forwarded to www.zeroarticles.info, so we can technically call that *.zeroarticles.info will forward to host name.

    (Note: I have added domain redirection for www.zeroarticles.info to www.myblog.com.np, so Wildcard DNS will point anything to the www.zeroarticles.info and my .htaccess code will then redirected to www.myblog.com.np | Don’t be confused on that thing.)

    Setting-up wildcard DNS must require access to Editing DNS Zone and httpd.conf

    Here is the easy process for setting up Wildcard DNS on your linux system.

    Step 1:

    Add a New ‘A’ Record for your domain. You’ll need to put an * in the first box, followed by adding your server IP address in place of “205.234.97.76″. Your IP address should be in one of the other entries in this screen where you can easily copy/paste it.

    Here is a screen shot of what it looks like:
    [​IMG]

    Step 2 :

    Find your domain entry on httpd.conf edit it and save it.

    What you are going to do here, is edit the line that looks like:

    ServerAlias yourdomain.com
    to:
    ServerAlias: *.yourdomain.com yourdomain.com

    It must be like below after editing:

    [​IMG]

    Now the Wildcard DNS is ready for your domain.

    Please Note That If you want to run more than one website on the same IP address, you need to have a NameVirtualHost directive. Edit your httpd.conf, and add the following before your first VirtualHost directive:

    NameVirtualHost IPadress:80
     
    thapame, Nov 7, 2007 IP