said by Quaoar
:Ok, let's be frank: your modem was not rented from Comcast, nor is it a private purchase. Your modem was a hand-me-down from someone else, or it is a lost/stolen modem.
Comcast accounts for every modem's MAC address. Yours does not meet requirements. You will have to replace your modem with a rental from Comcast or a purchase of a new modem.
If you have no account with Comcast, that is a separate issue. You cannot simply connect a modem to what appears to be a live line and hope that you gain access without an account and an acceptable modem. Call 1800comcast.
Q
The poster has stated that they have had an account with CC "for awhile now"...