I buy a refurbish Linksys router and it have work well now for over a year so I feel that buy a refurbish Linksys modem be a fairly safe bet . how wrong I be . as instruct I call comcast to give they the Mac address of the router however could not get the modem to show up with comcast . we try for hour with several different technician and supervisor but to no avail . add to this there be a no return policy for this unit . do not waste you money .