Ethereal isn't wireshark. I believe it used to be called ethereal, but now ethereal is just the packet interpreter part.
Anyway, you should have packages called "wireshark" and "wireshark-gnome." They are then either invoked thru the Start Menu at Internet->Wireshark Network Analyzer or by typing "wireshark" from a console. If neither of those are present, do a "whereis wireshark" from a console. If it doesn't show up, do "yum install wireshark-gnome." It should install everything you need.
If you're running KDE, I dunno where it would be from the menu. You should be able to invoke it from the console regardless, I'd think.