Controlling Devices on My Xfinity home wifi network

Perhaps your neighbors are inadvertently connecting to your network / gateway device via the MoCA feature that's built into it. MoCA (Multimedia Over Coax Alliance) is an alternate hardwired way to connect devices to a home network if ethernet cabling can not be used/run. It uses the existing coax cable wiring instead of ethernet cabling. 

If the MoCA feature is enabled, and you do not have a PoE (Point of Entry) MoCA filter installed on the coax line, yours, and your neighbor's gateway devices will be able to connect with each other like one big network. 

Disable it if you aren't using it. If you are, install a PoE MoCA filter on the input port of the first splitter off of the street drop to keep the MoCA signal in your premises and to keep the neighbor's signals out. Your neighbors should also have PoE filters installed.

To disable MoCA on your device. First, unplug the coax cable line from the jack on the gateway device. Then go to the gateway login http://10.0.0.1    

Default login info is:
Username: admin (all lowercase)
Password: password

Once in you will find the drop-down on the left of the screen that is labeled “Connections”.

Click the drop down---> click MoCA---> right side of screen click “disable”---> save changes.

Bear in mind that we've seen many posts here that the MoCA feature gets turned back on with their overnight re-boots / updates for the device. The best policy is to be sure to use that PoE filter ! Amazon has them: https://www.amazon.com/SNLP-1GCW-Filter-Eliminate-Multi-Room-Interference/dp/B07SLD9QPH     

Or you may be able to get one for free at your local Comcast / Xfinity store. Or book a tech to come out and install one for you.

If the MoCA feature is not being used on your home network, you can put the PoE filter right at the back of your gateway device instead.

EG…

Thanks for the tip. While I’m not familiar with MoCa, I know we’re definitely not using it, so plugging another possible hole for a bit of config and a $10 investment is a good win, so thanks.

However, what I’m really after is to have full control of my own wifi network, which allows me as admin to:

1. Delete any device connection from my network WITHOUT having to disconnect it first. As I said, if I can’t identify the device in the first place from it’s name, MAC, etc., how can I then disconnect it? 
2. Assign a permanent IP address to each device connected to my network based on the devices MAC address.

3. Give each device attached to my network a permanent name, again based on the above permanent IP address and MAC address. Names of connected devices are often unintelligible and, essentially, controlled by the device itself. Some make sense, some are gobbledegook.

4. Block devices from connecting to my network based on the MAC address.

Having logically named devices with permanent admin assigned IP addresses will provide better security, by allowing me to easily review what’s connected to my network, easily see unknown/unidentified devices and, with the ability in #1 above, delete the unknown, unidentified or unwanted devices.

All of these features were provided through my previous ISP and their router. Why doesn’t Xfinity provide the basic admin network management features? Or, if they do, how can I perform them?

Cheers, TheBigViking

Quite welcome ! I'm not a Comcast employee. And I'm not using their equipment, so I can't advise on those points, sorry. Perhaps someone with that knowledge will chime in. Good luck !