I am using ProtonVPN, and have (or so I thought) set up qBittorrent to bind to the network interface that ProtonVPN is using (tun0). The connection symbol turns red if I turn off the VPN, and downloads will stop. However, when checking the torrent address on ipleak.net, it seems that this bind is not working properly - my real IP shows up after I have disconnected my VPN. I thought that there shouldn't be any connections made when traffic is not via the tun0 interface, so that my real IP should never be known by the detection tool. Am I wrong?
I have not configured the kill switch, but perhaps I should do so?
I'm almost certain when using the official proton VPN app that proton creates a "proton0" network interface, or something similar, instead of using tun0. So you would have to bind to that interface instead of tun0.
I can't remember for definite, its been so long since I used the official app.
I'm not sure it explains your problem though since you're bound to tun0 anyway.
That was the case until the recent update to the Linux GUI client. I had to change the network interface bind in qBittorrent because the proton0-one stopped appearing. I assumed they had just made some changes, but could this mean that something is faulty with my install?
Its pretty weird, being specifically bound to tun0 and still having your IP show after disconnecting, makes it seem like there is something else running tun0 like openVPN or Wireguard without a kill switch enabled and they're just not connected to a VPN, if you've ever used them?
You could probably test this if you exit qbittorrent completely and disconnect from your VPN then open qbittorrent again and connect to another network interface in qbittorrent like wlan0 and save it. Then reopen that setting and see if tun0 is still an option. I don't think it should show up, if it does something is keeping tun0 active.
Either way, I would suggest uninstalling ProtonVPN v3 and v4 and reinstalling v4, maybe something is getting mixed up with v3 and v4 files?
tun0 goes away when I am disconnected, so I don't think anything is keeping it open. I noticed that connections in Proton VPN were set to UDP, so I changed this to TCP and this seems to have worked. Will still want to do more testing to be sure.
I don't seem to have v3 installed, by the way. The old GUI tool seems to have been uninstalled when upgrading, and the CLI tool I unisntalled myself.