One often requested feature is the ability to put a domain name on a sub-blog. Most people are unsure of what to call it, so I’ll tell you – domain mapping. While there has been a few ways to approach this in the past, it’s now easier with Donncha’s WordPressMU Domain Mapping plugin. It also just had an update, so if you have been using it, upgrade it.
Installation is easy, with one extra step. Drop the plugin file into the mu-plugins folder, and sunrise.php into the wp-content folder. Open up wp-config.php (in the root folder) and find the line like this:
// define( ‘SUNRISE’, ‘on’ );
It’s pretty far down there. Take those two // away from the front so the command will run.
Since we placed the plugin in mu-plugins, we do not have to activate it. You’ll find the menu for it under Tools. If you haven’t done the above step with the config & sunrise files, you’ll get a helpful error message.
One thing I want to point out right here is that you need to do this *while in the backend of the blog you want to map*. This plugin was designed so that the user of the blog in question would do this, not always the admin. If you’re at the main blog and you go to map a domain, you’ll re-map the domain of the *main blog*. (ask me how I found this out. LOL)
Fill out the fields, click the button. That’s not all though. The domain itself needs to know where to go.
I usually handle this two ways:
– add an A record pointing to the IP of my WPMU install (works if the IP address also resolves to the WPMU install)
– park the domain on top of the WPMU domain (better on shared hosts)
You can park the domain first, and then set it up in the backend. The order of these steps don’t really matter.
If you are looking for a paid solution, please consider the Professional Domain Mapping Plugin. It will completely hide the originating domain, and it also comes with an extensive PDF manual with step by step instructions (with screenshots!) for some of the top webhosts.