The netgear one is http-get, and you should treat it as thus. I'd suggest you don't use xhydra to begin with, start with the command line version till you get to know how it all works. Read the manual etc. A good solid understanding of authentication mechanism's would be better than just wading in with the GUI.
That said, I just a quick one across my development router to be sure I had the syntax correct, so here is a sample against a known username with a password file:
hydra -l root -P pw.lst -t 36 -m / 192.168.1.100 http-get