Two modems can be used in the same house, however, a second hard line of internet service will be needed. Every ISP (Internet Service Provider) just allows one modem per account; so, if someone wants to acquire a second modem, a second internet service has to be paid!
Can you hook up 2 modems to one cable line?
No, you cannot connect a second modem to his cable line.
Can you have 2 cable modems?
Rick’s answer: Yes Michael, it’s indeed possible to have multiple cable modems in the same house, and it isn’t all that uncommon. All you need to do is call Comcast (1-800-COMCAST) and tell them you want to sign up for an Internet-Only account.
How do I add a second cable modem?
You plug one into an electrical outlet in each room and then run an Ethernet cable from your computer to the box in the room where the computer is located and another Ethernet cable from the box in the outlet where your current cable modem is located to a router or switch in that room.