which coax line to connect to cable modem?

[Navigatn]

I recently moved to a new house which has a centralized box in the master bedroom closet which has a lot of cat5 and coax lines coming out of it. I'm trying to set up my cable internet and need to figure out which coax line I should connect to my cable modem. Each coax line is labeled to a room (master bedroom, family room, living room, etc.), and there is 1 DMARC. There is a second DMARC coax which is connected to a second family room coax line. Now i'm left with all the unconnected coax with the room labels and the second DMARC unconnected. Which one should I connect to my modem?

The house had Directv and Cox internet prior to me moving in. I'm guessing the Coax to use would be the open family room or DMARC line. I'm not sure why 1 DMARC is connected to the family room coax, and the other DMARC and family room coax are unconnected. I'm guessing the previous family had the Directv DMARC connected to the family room coax so they can watch TV in that room. Which would mean the second unconnected DMARC coax is the line in for cable internet. I'm just not sure why there is a second unconnected family room coax.

 

[Alabalcho]

You should first start by identifying where each cable is going. You can do that with $10 multimeter, and piece of wire to make short at the other end of the cable.

As for where to connect your modem - you need to sign up with an Internet provider, so that the cable which comes to your house has Internet service. When the service is commissioned, the technician will have the (hard) task to "ring" the cables.