Modem stops working between plugging it into different devices?

I have a Comcast Motorola Surfboard rental modem. It works fine, great speeds etc etc. It has no router or bridge support.

I use this modem to connect to the web on my ps3 and PC. What I have been doing is simply unplugging the ethernet cord from one device, and putting it in the other device to switch. But of course things can't be simple...

Every time I switch devices, the modem tries to reconnect and does a cycle where every time it only reaches the "Send" light. So I have to power cycle my modem and wait about a half hour before my connection resumes...

I read something about PPPoE, but Comcast doesn't even use it so that won't help.

 

You shouldn't need to wait a half hour, but you will need to power cycle the modem. A cheap router would resolve this.