Problem:
I cannot access the web gui from a different subnet. I've got DSS running on 192.168.5.x and am trying to access it accross a VPN of 192.168.3.x. I can ping everything on the .5 subnet just fine, except for the DSS box.
Solution:
The default gateway for the used ethrent was not set correctly. As soon asit was set it, the web gui was accessable from the other subnet.