No Sh__ !!!
For folks that ought to know networking inside and out, Xfinity seems brain-dead.
I put a rather detailed explaination out on this dialog in response to the XH engineer's note that appears several messages back in this dialog. Simply put, XH needs to provide it's own modem and provisioning that exists on a cable split ... they have no right to ussurp Xfinity Internet's public IP address and put my home network on a private IP address (one not accessible or broadcast outwardly to the WAN) behind their router when I pay for the Xfinity Internet service separately and descretly from XH.