Make all subdomains point to root unless otherwise specified

Question

I'd like all subdomains that aren't being used for anything else to go straight to my domain.

ns1.mydomain.com.   A   198.123.44.55
ns2.mydomain.com.   A   198.123.44.66
*.mydomain.com. CNAME   mydomain.com
webdisk.blog.mydomain.com.  A   198.123.44.55

However, say I have subdomain blog.mydomain.com which I still want to behave as a normal subdomain. I would like the following to happen:

     mydomain.com -->      mydomain.com
 www.mydomain.com -->      mydomain.com
 abc.mydomain.com -->      mydomain.com
blog.mydomain.com --> blog.mydomain.com

Is this possible?

Solution

If you are in a shared hosting with a single directory, you can use mod_rewrite in .htaccess to redirect all the subdomains to the root.

Adapted from: https://stackoverflow.com/questions/5966827/redirecting-multiple-domains-urls-to-one-canonical-domain.

RewriteEngine on
RewriteCond %{HTTP_HOST} !^example\.com [NC]
RewriteCond %{HTTP_HOST} !^blog\.example\.com [NC]
RewriteRule ^/?(.*) http://example.com/$1 [L,R=301,NE] 

Comments

[brentonstrine]

Dang, I don't have access to the config file... I'm on a shared hosting plan.

[kkugelmann]

Hey, maybe you should contact your shared hosting provider if it's possible to configure such a behaviour. The Shared Hosting Provider I'm using for my private Sites offers such a configuration.

[phynam]

I am not familiar with Apache, but that seems to solve his problem at the server level for a shared hosting plan. However, I believe there will still need to be a DNS record to tell browsers where to navigate to. This can be accomplished by creating a Wildcard DNS record. To do this, create an A record pointing to the server with * as the subdomain.