Connecting with client-benchmark in Windows 11 terminal to rust Signaling server running in WSL2 fails

[zorro2055]

Hi,
I am wondering if anyone has figured this out. A TCP initial connection appears to happen, but the websocket connection fails. I have windows port forwarding from port 9000 to WSL2 port 8000. Any suggestions to fix this?

SSH did work using a similar process with the ssh server in WSL2 and the ssh client in Windows 11, but this is not. Here is the output from the client-benchmark running in a Windows 11 terminal:

C:\Users\xxxxx\Documents\libdatachannel\build\examples\client-benchmark.exe -d 300 -w 192.168.1.144 -x 9000
STUN server is stun:stun.l.google.com:19302
The local ID is X26F
WebSocket URL is ws://192.168.1.144:9000/X26F
Waiting for signaling to be connected...
2025-12-10 13:54:23.368 INFO  [23696] [rtc::impl::TcpTransport::processConnect@463] TCP connected
2025-12-10 13:54:44.392 WARN  [23696] [rtc::impl::TcpTransport::process@385] TCP connection terminated
2025-12-10 13:54:44.393 INFO  [23696] [rtc::impl::TcpTransport::process@433] TCP disconnected
WebSocket closed
2025-12-10 13:54:44.393 ERROR [23696] [rtc::impl::WsTransport::incoming@194] WebSocket handshake failed

Details:

• Command used to launch signaling server in WSL2:

xxxxx@DESKTOP-UJKIK1U:~/libdatachannel/examples/signaling-server-rust/target/release$ ./libdatachannel_signaling_server_example 192.168.1.144:8000
Listening on 192.168.1.144:8000

• I'm operating WSL2 in mirrored networking mode which gives WSL2 the same IP address as the Windows 11.
• I tested connecting client-benchmark in WSL2 to the signaling server in WSL2, and it works. Here is the output:

xxxx@DESKTOP-UJKIK1U:~/libdatachannel/build/examples/client-benchmark$ ./client-benchmark -d 300 -w 192.168.1.144 -x 8000
STUN server is stun:stun.l.google.com:19302
The local ID is R2eo
WebSocket URL is ws://192.168.1.144:8000/R2eo
Waiting for signaling to be connected...
2025-12-10 14:03:05.895 INFO  [830] [rtc::impl::TcpTransport::processConnect@463] TCP connected
2025-12-10 14:03:05.900 INFO  [830] [rtc::impl::WsTransport::incoming@128] WebSocket client-side open
WebSocket connected, signaling ready
Enter a remote ID to send an offer:

• Used this command in Windows 11 powershell to forward from port 9000 in Windows 11 to port 8000 in WSL2:
  netsh interface portproxy set v4tov4 listenport=9000 listenaddress=0.0.0.0 connectport=8000 connectaddress=192.168.1.144 protocol=TCP
• If this rule is not used, a TCP connection is never established. Output of Windows 11 client-benchmark with the above rule not in place:

C:\Users\xxxxx\Documents\libdatachannel\build\examples\client-benchmark>client-benchmark.exe -d 300 -w 192.168.1.144 -x 9000
STUN server is stun:stun.l.google.com:19302
The local ID is CtFz
WebSocket URL is ws://192.168.1.144:9000/CtFz
Waiting for signaling to be connected...
2025-12-10 14:15:18.949 WARN  [25784] [rtc::impl::TcpTransport::attempt@215] Connection to 192.168.1.144:9000 failed
WebSocket error
WebSocket closed
Error: TCP connection failed

Tried the above command with port 8000 as well which gave the same output as above.

• Tried with the Windows Defender firewall disabled which made no difference.