Sorry to make a nuisance of myself, but being new to Slackware, I am still learning how to work with it.

Torrent applications cannot download, because the "port used for incoming connections" is closed. I have tried both ktorrent and Transmission. I have tried using a few different ports through the GUI, but they were also closed. (I know how to configure internet connections, but in case it is not obvious by this point, I have never had to deal with ports.) I have not made any modifications to my internet connection, such as using a firewall. I have tried Transmission and ktorrent with both i3 and Xfce.

I have tried the suggestion in this thread, regarding deleting ~/.config/transmission and re-starting Transmission
http://www.linuxquestions.org/questi...nt-4175502618/
, but it did not work. I have tried a few torrents from the site I usually use. The torrents are always good and the ones I tried currently have many seeders, so I am inclined to think it has something to do with a Slackware-specific configuration I must do.

So far, I have found documentation dealing with ports in regards to static DNS and using NIS and NFS, but not to things like torrent clients.

1) How do I open the ports (a port)?
2) Or just as good, links to documentation would be welcome.

i think, problem is not in your side.
do you contact your ISP with that questions?

If you are behind a firewall (and most Cable/DSL Internet routers in people's homes are running a NAT firewall) you will have to configure "port-forwarding" in your router.
That means, traffic arriving at your internet router address on port XXXXX will be forwarded to an internal IP address (your Slackware computer) on port YYYYY. The numbers XXXXX and YYYYY can be the same number but that is not mandatory.

Typically, you would have to port-forward BitTorrent protocol ports to your Slackware computer. Check your bittorrent client which ports it wants to use and configure those same ports on your internet router so that traffic gets forwarded to your computer. In my case (I ue qbittorrent) that is TCP port 6881.

Eric

I must use a router to access the internet, because the government's censorship software only recognises Windows, but ...
This problem only arose when I replaced Debian with Slackware, and nothing else has been affected. The browser can still access all the sites I normally visit. And as usual, I am not using a firewall and have not had occasion yet to use a proxy since installing Slackware.

The nature of an internet router (unless it has a PPPoE connection in which case it may be more complex) is that it is also a NAT firewall. Check your router.
Also, some torrent clients can use UPnP to negotiate a port with a capable router, so that you do not have to configure portforwarding and everything just "magically" works. Check your bittorrent client if it has that UPnP capability. QBittorrent has it.

Eric

I installed Transmission yesterday, and of course, ktorrent was included with the system. I tried both in i3 and Xfce. I logged out and back in several times during the day.

When I turned the computer on this morning, just for the heck of it, the first thing I did was start Transmission. I checked the port and the port was still closed. I then opened a browser and started visiting fora. While reading, I message popped up informing me that one of the torrents had finished downloading.

I have not checked ktorrent, but the problem seems to have been solved with Transmission by re-booting. Although that does not make any sense to me. Even though Transmission was installed yesterday, it should have worked without requiring logging out, let alone re-booting. And ktorrent should have worked, being part of the original system.

I encounter a situations, when you, turn on computer, can no have internet access until you not open any website on 80 port. maybe your ISP use something similar?
Try to test it...