"Comp1 , 2, and 3 ----> Router ---> Cable Modem (INTERNET) Cable Modem ----> Router <---- Comp 4, 5, and 6"
What about just Comp 1, 2, 3, 4, 5, 6 --> Router --> Cable modem?
By router do you mean an actual computer or one of those little Linksys boxes that you just hook into a cable modem?