After enabling the "map channel name to host header name" feature in MCMS you quickly will run into the problem that the only way to access your web site from now on will be to use the configured hostname - means the name of the root channel.
This can cause serious problems in case you need to have a separate authoring or test environment. When your production box is accessable as http://www.something.com then you also have to access your authoring or test server with http://www.something.com and it is not possible to use http://authoring.something.com or http://test.something.com.
To access different boxes with the same URL you would need to ensure that the same name resolves to different IP addresses. A common solution for this is to have an host file entry that is switched between the different IP addresses of the different machines.
A better solution would be if it would be possible still to use http://authoring.something.com but let MCMS think you entered http://www.something.com. This would completly solve this problem. But how can this be achieved?
Here is the solution.