One of the most annoying things that Comcast has done is to turn all their customers into unwitting public hotspots. Not to mention the potential security problems, this creates a new entry point to your network. They have buried it under three layers of menus, but you can turn it off:
- Goto comcast.net and log in.
Click on Users and Preferences
Manage Xfinity Wifi
While you are there, you might also want to uncheck the “allow comcast to call you on your phone with ads” option as well.