I have a Debian server on which I installed Open DC Hub for my network.
I also installed on the same station ldcc, dctc (direct connect textbased client) on it in order to share files for my network as a client. I mention my server is connected to Internet with a firewall

wich don't let the dc hub to be seen from outside.

It seems with the client on the server I can download and search from other clients on the network(max 5

results), but I can't download from any client on the network from my server. It says: "No slots

available" although there are 4 slots opened. The icon of my client on the server is with a wall. It

seems the client on the server is in passive mode.
What I have to do to make it work?
How to pass in active mode?

Thank you in advance!!!