Ah, found the answer. The lines of code I showed in the previous code, wasn't the exact code that I used to test all this. I added the 192.168.0.2 part to it, assuming it wouldn't matter. I didn't test the file after the adding of that line.
Well, I decided to give it another go 2 mins ago and it turned out I could ping every server1 alias, but not the glenn aliases. After some thinking I decided to put a newline (Enter) after the last line, leaving a blank line at the end of the file. And, as you may guess, that worked!
I tested some more, so I removed the blank line and the 192.168.0.2 part and now I couldn't ping server1 aliases anymore. Added a newline at the end of the file and now it did work. Very strange indeed, I don't understand why you need to put a newline at the eof, but hell, it works now!
Oh, Apache2 works too now, or at least, it starts up. I am going to test now.