Works great on Comcast ! Got rid of the crappy old Comcast rental modem which cost $ 84\/year ... forever . fast , easy to setup , easy to open packaging ! you have to return you old rental modem to Comcast first before they let you switch it over . write down the model number and take one of the sticker it come with that have the serial\/mac address on it when you return you old one and they will switch it over .