Network problems using WSL2

My answer is based on the article Running a public server from WSL 2, where the theory is that Windows creates a virtual adapter that isn’t properly bridged with the internet network adapter.

The article raises the following points:

1. In WSL ensure that your server is using IPv4

2. If you are using a firewall in WSL, allow the relevant port (3390)

3. In Windows, forward your port from the public IP port to the WSL port in Command Prompt or Powershell with admin rights:

    netsh interface portproxy add v4tov4 listenport=$PORT listenaddress=0.0.0.0 connectport=$PORT connectaddress=127.0.0.1
   

4. In Windows, allow the port through the Windows firewall using a new Inbound Rule.

5. For access from the internet, setup port forwarding for the port in the router.

A YouTube video describing the process with some small differences is WSL 2 Networking.

I needed three things for this to work:

1. Upgrade to the latest version of windows
2. wsl --shutdown
3. Settings > Network & Internet > Network Reset as described here

I ran into this as well; this is my solution: WSL2-PortForward.cmd

It takes care of the port proxy and firewall rules for you and cleans up after itself.

@ECHO OFF
SET LXDISTRO=MyWSL2vm & SET WSL2PORT=3399 & SET HOSTPORT=3398
NETSH INTERFACE PORTPROXY RESET & NETSH AdvFirewall Firewall delete rule name="%LXDISTRO% Port Forward" > NUL
WSL -d %LXDISTRO% -- ip addr show eth0 ^| grep -oP '(?^<=inet\s)\d+(\.\d+){3}' > IP.TMP
SET /p IP=<IP.TMP
NETSH INTERFACE PORTPROXY ADD v4tov4 listenport=%HOSTPORT% listenaddress=0.0.0.0 connectport=%WSL2PORT% connectaddress=%IP% 
NETSH AdvFirewall Firewall add rule name="%LXDISTRO% Port Forward" dir=in action=allow protocol=TCP localport=%HOSTPORT% > NUL
ECHO WSL2 Virtual Machine %IP%:%WSL2PORT%now accepting traffic on %COMPUTERNAME%:%HOSTPORT%

Run the command:

.\WSL2-PortForward.cmd

Result:

WSL2 Virtual Machine 172.17.109.95:3399 now accepting traffic on MYCOMPUTER:3398