Cable Box RJ-45 for URC Automation connection using LAN

I have Xfinity service and an Xfinity Cable Box Model: XG2v2P that has an RJ-45 port on the back panel.  I am getting a home automation control system installed and the installers said that the best way to program their Universal Remote Control for cable TV on my home theater is through my local area network (LAN) where their Universal Remote controller box (MX-5) and my cable box (XG2v2P) are connected to my LAN and on the same subnet. I'm preparing for the install and connected my cable box to my LAN but it does not show up in my router's DHCP table. Is the RJ-45 port on the back of my cable box ready for use on my LAN? Is there something that Xfinity must do first to activate it?

Thanks!!