ok, after many, many hours of trying around and reading tutorials, i slowly start to understand. But not yet completely.
I have successfully managed to turn my existing (german) wordpress installation (site1.de) into a multisite. I want to create a second blog (english), which would run through site2.de.
So, german blog under site1.de.
I've added a new wordpress site ("test") which corresponds to site1.de/test. It works.
In the "Network admin", the "Domain mapping" points to "site1.de" (I don't have an IP).
In the "test" admin area, I click on "Domain mapping", "add new domain" and enter site2.de, as primary domain.
Now, there is something I have to do on the webhosting administration side. I can change the domain attribution, so that site2.de gets redirected to site1.de.
But when I do this, my site2.de get's indeed redirected to site1.de, but not site1.de/test. And site1.de/test gets redirected to site1.de.
What am I doing wrong? Thanks so much for any hints!