Hi there!

First of all I would like to thank you for an awesome piece of software!

I had a little problem with opening the ports in my router for the bittorrent traffic. I configured ktorrent to use the port 12321 (tried a couple of other ports as well) and then I forwarded that port in my routers configuration interface (Netgear WNR3500, latest firmware) to my computer. 'netstat -atn|grep 12321' said it only listened to tcp6 on that port and I didn't get any connections from anyone. I tried this little test http://www.utorrent.com/testport?port=12321 and it said my port wasn't open and didn't accept connections. I also tried to enable UPnP on my router and enabled the UPnP plugin, with the same result.

When I recompiled my linux kernel and disabled IPv6 everything worked like a charm (with or without the use of UPnP).

I'm using the package in the current debian amd64 tree (3.3.3+dfsg.1-1).

If this issue *should* be resolved by my router somehow or if it is fixed in the 4.0 version I apologize for taking up your time.

jonas wrote:Hi there!

First of all I would like to thank you for an awesome piece of software!

I had a little problem with opening the ports in my router for the bittorrent traffic. I configured ktorrent to use the port 12321 (tried a couple of other ports as well) and then I forwarded that port in my routers configuration interface (Netgear WNR3500, latest firmware) to my computer. 'netstat -atn|grep 12321' said it only listened to tcp6 on that port and I didn't get any connections from anyone. I tried this little test http://www.utorrent.com/testport?port=12321 and it said my port wasn't open and didn't accept connections. I also tried to enable UPnP on my router and enabled the UPnP plugin, with the same result.

The fact that netstat only shows tcp6, should not be a problem, I see the same, and I do get incoming connections. If IPv6 is enabled in linux, IPv4 will still work, and binding to all addresses should result in accepting incoming IPv4 connections.

I also wouldn't trust that test, the first time I tried it, it didn't detect the port was open, the second time it did.

When I recompiled my linux kernel and disabled IPv6 everything worked like a charm (with or without the use of UPnP).

I'm using the package in the current debian amd64 tree (3.3.3+dfsg.1-1).

You don't need to recompile the kernel to disable IPv6

George wrote:The fact that netstat only shows tcp6, should not be a problem, I see the same, and I do get incoming connections. If IPv6 is enabled in linux, IPv4 will still work, and binding to all addresses should result in accepting incoming IPv4 connections.

I also wouldn't trust that test, the first time I tried it, it didn't detect the port was open, the second time it did.

Okey. I'll make some few tests later this week just to make sure

You don't need to recompile the kernel to disable IPv6

Perhaps not, but I was updating it to a new version anyways and will probably do that again now

George wrote:The fact that netstat only shows tcp6, should not be a problem, I see the same, and I do get incoming connections. If IPv6 is enabled in linux, IPv4 will still work, and binding to all addresses should result in accepting incoming IPv4 connections.

Turns out i needed to disable net.ipv6.bindv6only. It was enabled in the file /etc/sysctl.d/bindv6only.conf on my debian system and the comments in that file said it was "the default behaviour of all modern operating systems".

By running /sbin/sysctl -w net.ipv6.bindv6only=0 and restarting ktorrent I get incoming connections (according to netstat), which I didn't when I just listened to the IPv6 socket.