How to set up port forwarding on a ZXADSL VII modem?

Hello
I have been attempting to forward a port on this specific router for a few days now, yet every single effort has proven fruitless. This device features some rather peculiar configuration options compared to my previous hardware, though I believe I have eventually deduced the necessary parameters. However, there is a final checkbox that appears greyed out, despite the interface indicating it is mandatory.
Here is the visual representation of the issue:
View on imgur

Am I fundamentally misunderstanding the procedure, or is this simply a defect within the router itself??
Thank you.

Here’s what I’m seeing on my end:

https://img.torrenthr.org/images/2017/06/27/Izrezak.png

Paul Bailey98 said:My situation looks like this:

https://img.torrenthr.org/images/2017/06/27/Izrezak.png

It won't allow it; I simply cannot get that final checkbox to register properly.

Look, you don't even have to manually enter it—it just fills itself in automatically once you punch in the LAN host, start, and port info. 🤔

Kill any adblockers or content filters you've got running.
Maybe try a different browser...

My sincere thanks to everyone for the assistance.
The port is finally open.
The error stemmed from my own oversight; I had attempted to use a paste function when manual entry was required.
Now, however, a secondary issue has resurfaced—one that has plagued me ever since I installed this archaic version of Windows 7..
Bit Comet is reporting that the port is closed, despite everything functioning perfectly until this moment.
Regardless, I suppose I shall simply have to accept it..

Maybe try a clean reinstall... might shake things up and get those ports sorted out properly. Or just switch over to qBittorrent—honestly, it’s my go-to, works better than anything else I've tried.

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