I have recently discovered that there is some TVs and other equipment that is in my network. I would like to blacklist them/or prevent them from getting in my network. I have done the following: 

I want to: Block or allow specific client devices to access my network (via wired or wireless).

1. Log in to the web-based interface of the router. ...
2. Go to Advanced > Security > Access Control.
3. Enable Access Control
4. Select the access mode to either block (recommended) or allow the device(s) in the list.

To block specific device(s)

1) Select Blacklist and click Save.

But to my surprise, there is no Blacklist there.

Is there another way to Block or Blacklist an IP address or device?

Thank you for your help.