Add an option to check whether the listening port is forwarded properly.

[NeverSm1le]

Setting up port forwarding can be a pain sometimes, and have an option to check if the port is correctly assigned to qBittorrent helps. Hope the team can add it in the future.

[Lokotito]

Sometimes the icon don't check the port status correctly, I use QB in a encapsulalted private IP, with none open port, but icon says that port is OK with "GREEN" icon. It will be a useful feature to have an option to check better the port status.

[825i]

There's no guarantee that even if this feature is added, that qBittorrent will be able to reliably tell whether or not the port is open. This is something that you need to verify yourself via other means. Different trackers also have different ways to determine whether or not a person has open ports and some trackers may report that your ports are closed even if they aren't.

If you have followed your router's documentation and do not have a firewall actively blocking transmissions on the port in question then the port is open. Port information is available on any router made in the last 10 years.

[dialectics]

This is actually a good idea. Please, while considering the request, keep in mind the following:

1. Upload speed of home connections keeps rising over the years, having just reached a FTTH level in many places in the world. Thus, it is all the more important now, more than ever, that an average user should be able to share as much as possible. He CAN make a difference, its not only seed farms that can do it.
2. qbittorrent isn't a client that is specific for IT professionals or users with proficiency in networking. It should strive to give every help available to people who are joining the sharing effort.

Considering the above, i think that a "check port" feature, is a really useful feature, despite the fact that it can give false positives/negatives. I would even suggest that the request is extended, to also include a link to a quick tutorial/troubleshooting guide. For example, many people relied on the automatic uPNP of qbittorrent to do the port forwarding in the past. However, as house networks are getting more complicated, e.g. if you are in a subnet of your house's network (i.e. behind two routers), relying on UPnP won't be enough. House networks will keep increasing in complexity, so a port forwarding guide is certainly needed, in my opinion.