This is incorrect. The Config Tool will search for, and find Dahua cams on other segments. I've included a screen shot of how to accomplish this.I dont believe the config tool allows you to connect unless you are in the same range of IP. I was trying to test and setup these cameras at work before I install them at home so changing the internal IP to match my network here won't work.
I uploaded it for you above. I added it after the fact. Should have mentioned the zip file.Thanks, that could be why I didn't see that option. But I do not see your version listed on dahua site. ConfigTool - Dahua Wiki