The CM MAC (Cable Modem MAC address) and Serial Number of your cable modem are printed on the bottom label. See below for examples of where to find the information.
Model MB7220:
Model MB7420:
Model MG7310:
The CM MAC (Cable Modem MAC address) and Serial Number of your cable modem are printed on the bottom label. See below for examples of where to find the information.
Model MB7220:
Model MB7420:
Model MG7310: