Blocking IPs doesn't seem to work.

I followed the instructions from this thread: https://forums.comodo.com/index.php/topic,5147.0.html

but it doesn’t seem to work, as in the connections tab I still see the application sending data out to the IP address.

Can anyone help me figure out how to block the IP?

Try this, and remember that the rule needs to be at the top of the network monitor list.

Action : Block
Protocol : IP
Direction : Out
Source IP : Any
Destination IP : The IP or domain you want to block. (www.yahoo.com)
IP Details : Any

Let me know if it works.
Good luck!

Thanks, moving it to the top of the network monitor list seems to work without doing anything else, but I am wondering do I need to move other entries when I need to block more IPs?

Since network monitor reads from the top and down, you have to block them before the allow rule that lets them through. Just add them at the top.

If you have a lot of IP blocking to do, you can try Peerguardian 2.