i need help hooking up to my comcast modem i want to hook up my computer and xbox to my modem but there is only one ethernet plug on the modem somebody told me i could get a switch but when i went to bb today they did not know what i was talking about.right now i am just upluging in the one i want to use but i am affraid i may wear out the inputs with all that uplugging and plugging in.THANK YOU