IPv6 peers not connecting

[burajiruhito]

Support guidelines

• I've read the support guidelines

I've found a bug and checked that ...

• ... the documentation does not mention anything about my problem
• ... there are no open or closed issues that are related to my problem

Description

rTorrent is unable to connect to any IPv6 peers when running inside the crazymax/rtorrent-rutorrent container. This occurs even when IPv6 is fully functional inside the container and reachable externally.

Expected behaviour

rTorrent should be able to connect to IPv6 peers.

Actual behaviour

rTorrent fails to connect to any IPv6 peers.

Steps to reproduce

Run the container with Gluetun (VPN) as the network stack.

Confirm that both IPv4 and IPv6 addresses are assigned and working inside the container (ip -6 addr).

Use .torrent files from public and private trackers that have known IPv6 peers.

Observe that no IPv6 peers connect.

Docker info

Client:
 Version:    27.0.3
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.15.1
    Path:     /usr/libexec/docker/cli-plugins/docker-buildx

Server:
 Containers: 7
  Running: 6
  Paused: 0
  Stopped: 1
 Images: 7
 Server Version: 27.0.3
 Storage Driver: overlay2
  Backing Filesystem: xfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: inactive
 Runtimes: runc io.containerd.runc.v2 nvidia
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: ae71819c4f5e67bb4d5ae76a6b735f29cc25774e
 runc version: v1.1.13-0-g58aa920
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.6.78-Unraid
 Operating System: Unraid OS 7.0 x86_64
 OSType: linux
 Architecture: x86_64
 CPUs: 12
 Total Memory: 23.41GiB
 Name: servidor
 ID: 
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false
 Product License: Community Engine

WARNING: No swap limit support

Docker Compose config

This container is deployed via Unraid Docker GUI, which does not use a docker-compose.yml file. Below is a compose-equivalent configuration based on Unraid’s template:

services:
  rutorrent:
    image: crazymax/rtorrent-rutorrent
    container_name: rutorrent-crazymax
    network_mode: "container:GluetunVPN"
    environment:
      - PUID=99
      - PGID=100
      - RT_INC_PORT=27270
      - XMLRPC_PORT=7500
    volumes:
      - /mnt/user/appdata/rutorrent-crazymax/data:/data
      - /mnt/user/appdata/rutorrent-crazymax/passwd:/passwd
      - /mnt/user/arquivos:/downloads
    ports:
      - "8095:8080"
      - "27270:50000"
      - "6881:6881"

Logs

[s6-init] making user provided files available at /var/run/s6/etc...exited 0.
[s6-init] ensuring user provided files have correct perms...exited 0.
[fix-attrs.d] applying ownership & permissions fixes...
[fix-attrs.d] done.
[cont-init.d] executing container initialization scripts...
[cont-init.d] 00-fix-logs.sh: executing... 
[cont-init.d] 00-fix-logs.sh: exited 0.
[cont-init.d] 01-fix-uidgid.sh: executing... 
Switching to PGID 100...
Switching to PUID 99...
[cont-init.d] 01-fix-uidgid.sh: exited 0.
[cont-init.d] 02-fix-perms.sh: executing... 
Fixing perms...
[cont-init.d] 02-fix-perms.sh: exited 0.
[cont-init.d] 03-config.sh: executing... 
Setting timezone to America/Campo_Grande...
Setting PHP-FPM configuration...
Setting PHP INI configuration...
Setting OpCache configuration...
Setting Nginx configuration...
Setting Nginx XMLRPC over SCGI configuration...
Setting Nginx ruTorrent configuration...
Setting Nginx WebDAV configuration...
Update healthcheck script...
Initializing files and folders...
rpc.htpasswd is empty, removing authentication...
webdav.htpasswd is empty, removing authentication...
Checking rTorrent local configuration...
Checking rTorrent configuration...
Bootstrapping ruTorrent configuration...
Setting custom config for create plugin...
Checking ruTorrent custom plugins...
  Copying custom httprpc plugin...
Checking ruTorrent plugins configuration...
Checking ruTorrent custom themes...
Setting GeoIP2 databases for geoip2 plugin...
Fixing perms...
[cont-init.d] 03-config.sh: exited 0.
[cont-init.d] 04-create-services.sh: executing... 
[cont-init.d] 04-create-services.sh: exited 0.
[cont-init.d] ~-socklog: executing... 
[cont-init.d] ~-socklog: exited 0.
[cont-init.d] done.
[services.d] starting services
[services.d] done.
2025/04/05 17:21:43 [notice] 512#512: using the "epoll" event method
2025/04/05 17:21:43 [notice] 512#512: nginx/1.26.2
2025/04/05 17:21:43 [notice] 512#512: OS: Linux 6.6.78-Unraid
2025/04/05 17:21:43 [notice] 512#512: getrlimit(RLIMIT_NOFILE): 32000:40000
2025/04/05 17:21:43 [notice] 512#512: start worker processes
2025/04/05 17:21:43 [notice] 512#512: start worker process 549
2025/04/05 17:21:43 [notice] 512#512: start worker process 550
2025/04/05 17:21:43 [notice] 512#512: start worker process 551
2025/04/05 17:21:43 [notice] 512#512: start worker process 555
2025/04/05 17:21:43 [notice] 512#512: start worker process 564
2025/04/05 17:21:43 [notice] 512#512: start worker process 580
2025/04/05 17:21:43 [notice] 512#512: start worker process 601
2025/04/05 17:21:43 [notice] 512#512: start worker process 628
2025/04/05 17:21:43 [notice] 512#512: start worker process 651
2025/04/05 17:21:43 [notice] 512#512: start worker process 749
2025/04/05 17:21:43 [notice] 512#512: start worker process 778
2025/04/05 17:21:43 [notice] 512#512: start worker process 833
[05-Apr-2025 17:21:43] NOTICE: fpm is running, pid 511
[05-Apr-2025 17:21:43] NOTICE: ready to handle connections

Additional info

The container is connected via Gluetun VPN, which provides both IPv4 and IPv6 connectivity.

The same .torrent files work with IPv6 peers in qBittorrent using the same Gluetun network.

Port forwarding is correctly set up for both IPv4 and IPv6.

[PiloUnk]

Hi,

I have the same setup as @burajiruhito with Gluetun and IPv6 support on Docker. Apparently rtorrent only binds incoming port on IPv4:

docker exec -it rtorrent-rutorrent sh
/ # ss -ltpun
Netid                State                 Recv-Q                Send-Q                               Local Address:Port                                 Peer Address:Port                Process
udp                  UNCONN                0                     0                                          0.0.0.0:39052                                     0.0.0.0:*
udp                  UNCONN                0                     0                                          0.0.0.0:43799                                     0.0.0.0:*
udp                  UNCONN                0                     0                                       127.0.0.11:45853                                     0.0.0.0:*
udp                  UNCONN                0                     0                                                *:48219                                           *:*
udp                  UNCONN                0                     0                                                *:53                                              *:*
udp                  UNCONN                0                     0                                             [::]:43799                                        [::]:*
tcp                  LISTEN                0                     511                                        0.0.0.0:8000                                      0.0.0.0:*
tcp                  LISTEN                0                     511                                        0.0.0.0:8080                                      0.0.0.0:*
tcp                  LISTEN                0                     128                                        0.0.0.0:6692                                      0.0.0.0:*
tcp                  LISTEN                0                     511                                      127.0.0.1:8001                                      0.0.0.0:*
tcp                  LISTEN                0                     511                                      127.0.0.1:8081                                      0.0.0.0:*
tcp                  LISTEN                0                     511                                      127.0.0.1:9001                                      0.0.0.0:*
tcp                  LISTEN                0                     4096                                    127.0.0.11:43301                                     0.0.0.0:*
tcp                  LISTEN                0                     4096                                     127.0.0.1:9999                                      0.0.0.0:*
tcp                  LISTEN                0                     511                                        0.0.0.0:3000                                      0.0.0.0:*
tcp                  LISTEN                0                     511                                        0.0.0.0:9000                                      0.0.0.0:*
tcp                  LISTEN                0                     4096                                             *:8007                                            *:*
tcp                  LISTEN                0                     4096                                             *:8888                                            *:*
tcp                  LISTEN                0                     4096                                             *:53                                              *:*
/ #

My incoming port is 6692, instead of having *:6692 it's clearly an IPv4 bind using 0.0.0.0:6692. I tried to set network.prefer.ipv6.set = true, network.bind_address.ipv4.set = <vpn_ipv4_ip> and network.bind_address.ipv6.set = <vpn_ipv6_ip> in .rtorrent.rc as advised by Rakshasa here and there without any luck.

Is rtorrent built with IPv6 support in this docker?