Version 4.6.4 does NOT listen to TCP/UDP port.

[GitGringo]

Version 4.6.4 does NOT listen to TCP/UDP port.

[stalkerok]

This is an internal issue with your system, something is blocking or a wrong network interface.

[GitGringo]

probably yes, but other services/software can work ordinary, so this is not excuse for QBT

[thomascrisan]

I've started experiencing the same problem on Arch Linux. Both Deluge and and kTorrent are working properly on the same system running under the same login. My router is actively seeing active UPnP redirects from both of these programs but nothing from qBittorrent 4.6.4.

[GitGringo]

looks like there are problem with discovering Ethernet devices for qBittorrent

[shama84]

Starting QBT as administrator with the contextual menu (right click option) helps?

[thomascrisan]

This was the problem for me: my network interface was set improperly.

Go to Preferences / Advanced and find "Network interface". Set it to "Any Interface" or find the one that works in your setup.

[xavier2k6]

@GitGringo Can you reproduce with qbittorrent 4.6.5?

[teohhanhui]

@xavier2k6 I'm facing this problem with qbittorrent 4.6.5 on Fedora 40:
https://bodhi.fedoraproject.org/updates/FEDORA-2024-d5e2d42a60

"Network interface" is already set to "Any interface" (the default) but qbittorrent only listens on localhost and Tailscale...

(N) 2024-06-10T13:53:34 - qBittorrent v4.6.5 started
(N) 2024-06-10T13:53:34 - Using config directory: /home/teohhanhui/.config/qBittorrent
(N) 2024-06-10T13:53:34 - Trying to listen on the following list of IP addresses: "0.0.0.0:55175,[::]:55175"
(I) 2024-06-10T13:53:34 - Peer ID: "-qB4650-"
(I) 2024-06-10T13:53:34 - HTTP User-Agent: "qBittorrent/4.6.5"
(I) 2024-06-10T13:53:34 - Distributed Hash Table (DHT) support: ON
(I) 2024-06-10T13:53:34 - Local Peer Discovery support: ON
(I) 2024-06-10T13:53:34 - Peer Exchange (PeX) support: ON
(I) 2024-06-10T13:53:34 - Anonymous mode: OFF
(I) 2024-06-10T13:53:34 - Encryption support: ON
(I) 2024-06-10T13:53:34 - UPnP/NAT-PMP support: ON
(I) 2024-06-10T13:53:34 - Successfully listening on IP. IP: "127.0.0.1". Port: "TCP/55175"
(I) 2024-06-10T13:53:34 - Successfully listening on IP. IP: "127.0.0.1". Port: "UTP/55175"
(I) 2024-06-10T13:53:34 - Successfully listening on IP. IP: "::1". Port: "TCP/55175"
(I) 2024-06-10T13:53:34 - Successfully listening on IP. IP: "::1". Port: "UTP/55175"
(I) 2024-06-10T13:53:34 - Successfully listening on IP. IP: "fe80::b621:302f:98e:75f2%tailscale0". Port: "TCP/55175"
(I) 2024-06-10T13:53:34 - Successfully listening on IP. IP: "fe80::b621:302f:98e:75f2%tailscale0". Port: "UTP/55175"

$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute 
       valid_lft forever preferred_lft forever
2: tailscale0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1280 qdisc fq_codel state UNKNOWN group default qlen 500
    link/none 
    inet6 fe80::b621:302f:98e:75f2/64 scope link stable-privacy proto kernel_ll 
       valid_lft forever preferred_lft forever
3: wlp1s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 92:56:88:cc:b9:55 brd ff:ff:ff:ff:ff:ff permaddr ac:c9:06:23:40:a4
    inet 192.168.1.204/24 brd 192.168.1.255 scope global dynamic noprefixroute wlp1s0f0
       valid_lft 42998sec preferred_lft 42998sec
    inet6 fe80::8e8b:ec31:478:f0a/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

$ sudo lsof -i -P -n | grep LISTEN
systemd-r  811 systemd-resolve   11u  IPv4   4017      0t0  TCP *:5355 (LISTEN)
systemd-r  811 systemd-resolve   13u  IPv6   4025      0t0  TCP *:5355 (LISTEN)
systemd-r  811 systemd-resolve   18u  IPv4   4030      0t0  TCP 127.0.0.53:53 (LISTEN)
systemd-r  811 systemd-resolve   20u  IPv4   4032      0t0  TCP 127.0.0.54:53 (LISTEN)
cupsd      983            root    6u  IPv6  15542      0t0  TCP [::1]:631 (LISTEN)
cupsd      983            root    7u  IPv4  15543      0t0  TCP 127.0.0.1:631 (LISTEN)
valent    2810      teohhanhui   19u  IPv6  32137      0t0  TCP *:1716 (LISTEN)
passimd   3403          passim    9u  IPv4  38925      0t0  TCP *:27500 (LISTEN)
qbittorre 3421      teohhanhui   38u  IPv4  33484      0t0  TCP 127.0.0.1:55175 (LISTEN)
qbittorre 3421      teohhanhui   40u  IPv6  33487      0t0  TCP [::1]:55175 (LISTEN)
qbittorre 3421      teohhanhui   42u  IPv6  33490      0t0  TCP [fe80::b621:302f:98e:75f2]:55175 (LISTEN)

If I change "Network interface" to wlp1s0f0, it's just stuck on:

(N) 2024-06-10T13:58:11 - Trying to listen on the following list of IP addresses: "wlp1s0f0:55175"

Workaround for now:

sudo systemd disable --now tailscaled

So it seems like qbittorrent is getting stuck on the Tailscale interface for some reason...