Before we can open ports for BCDC++, we need to figure out what ports BCDC++ is using. Here is a brief walkthrough on how to do that. Go ahead and open up BCDC++.
In the menu at the top of your screen click the file option. In the menu that drops down click the Settings link.
In the menu on the left hand side of the window that popped up click the Connection Settings link. You should see a TCP box and an UDP box. Enter a random port into each of these boxes. It doesn't matter what ports you choose, but a port numbers between 10000 and 60000 would be a good idea. A higher numbered port is generally the best to use, because most ISP's do not block the higher numbered ports. Please enter the port you chose for the TCP box into the box below.
Click the Security button near the top of the page.
Click the Application Monitor button near the left of the page.
We will list a series of lines here that will show you exactly how to setup Comodo Firewall's firewall for BCDC++. Go ahead and enter the settings shown below into the Network Control Rule menu.