FranciscoPombal
commented
4 years ago @kasper93
4.2.1 @ Windows 10. Tested also with 8e553ad and latest deps at the time.
I assume this means the libtorrent version you used was 1.2.5 or a more recent commit of the RC_1_2 branch, right? Either way for these kinds of bugs, let's not focus on 4.2.1 anymore, there have been too many important changes since then. The qbittorrent master commit you tested is recent enough, though.
When you have time, please post your debugging findings and ping the libtorrent maintainer if needed. libtorrent also underwent a lot of changes to related network code recently, might still need some polish.
xavier2k6
kasper93
luzpaz
stalkerok
Please provide the following information
qBittorrent version and Operating System
4.2.1 @ Windows 10. (10.0.1xxxx) Tested also with 8e553adc92c793cd9d0e6030fb91932ca3aca9ee and latest deps at the time.
What is the problem
IPv6 sort of works. I will share only high level observations as I did not debug it yet. I wanted to work on it last weekend, but didn't have time, so I figured to write it up so I don't forget.
BitTorrent will not connect to any IPv6 peers resulting in no transfer if IPv4 is not available
I tested with some IPv6 trackers and only listening on IPv6. I didn't get any connections. After enabling DHT it picked up some peers and worked fine.
Temporary/Privacy IPv6 handling
Currently qBittorrent listens and announces from all IPv6 addresses. While for IPv4 listing all addresses is reasonable. For IPv6 you can have situation that you have like 10 temporary addresses (aka. privacy) assigned to one interface. And it makes literally no sense to announce from all of them, dosing tracker... I know we can select specific address, but it is also suboptimal and default options should take this issue into account. Also form the privacy aspect, announcing form every IPv6 gives very nice mapping between our main and all temporary addresses to whoever is listening, not nice.
Without much thinking, here is possible solutions I see:
Also another issue is that if you setup qBittorrent to listen only on IPv6 addresses it will not be able to announce to tracker that is available only on IPv4. I feel that two things are mixed up here. We should be able to announce to IPv4 server even if we want to connect only to IPv6 peers.