Clients not connecting in CCcam

Hi,
I have just become aware that none of my peers are able to connect to my server at the moment. I am connecting to their servers OK.

I changed image from Open Vix Appollo to Open Vix Hades a few weeks back and believe my problem may have started then, though this could be coincidental.

I have a Vu+ duo now loaded with latest Hades image and CCcam 2.2.1. I have tried Black Hole and Open ATV with CCcam 2.3.0 and reverting back to Appollo but still the problem persists so would be grateful for any suggestions that might be worth a try.

Many Thanks.

The server listening port isn't open, just don't know why not. dns updater working fine.

Thanks for the advice. Unfortunately still not working (followed all steps in order given). I think I'll setup another router and give that a try. I've got an old Netgear one spare somewhere.