The Domain Mapper add-on lets you use one concrete5 install to serve content at multiple domains. You are still effectively running one website in the sense that there will be shared users, groups, files, themes, attributes, add-ons, etc. You can even copy pages from one "site" to another easily with this technique. What the Domain Mapper lets you do is point parked domains to specific spots on your site tree as a starting point for that domain. An example:

You own as well as and

You setup a site tree that looks like this:

By default, your site runs at so assuming pretty URLs is turned on, the following links work.

Now follow these steps:
1) Using cPanel or your other server management software, you need to "park" on your account. Once you do this any traffic coming to will get redirected to

2) Go to the Domains tab here, and enter in the domain name path and pick the "secondSite" page.

Now any traffic coming to the will see the content of the secondSite page, and their url will look like:

When they click links, they will continue to have the same domain in their URL field, but WILL see the full path of pages, so for example:


Note if you make a user account, be it admin or regular on any one of the urls, you will have effectively made an account on all of them. You will still have to login each time you visit a new URL however, as the user session is tied to the root domain. If you are making edits to the site, it probably makes most sense to login to as you will be able to visit each page in the site without the URL changing and logging you out. 

Domain Mapper Doing nothing in concrete5.4.1+ ?

Turn full page caching off and try again.
Full page caching was introduced in concrete5 version 5.4.1.  The point of full page caching is to display a cached page using very little resources.  The domain mapper ties into one of the events that is skipped durring the rendering of a cached page so it's logic is never run.