WSL 2 TCP NETWORK FORWARDING

wsl2-network.ps1

# WSL2 network port forwarding script v1
#   for enable script, 'Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope CurrentUser' in Powershell,
#   for delete exist rules and ports use 'delete' as parameter, for show ports use 'list' as parameter.
#   written by Daehyuk Ahn, Aug-1-2020

# Display all portproxy information
If ($Args[0] -eq "list") {
    netsh interface portproxy show v4tov4;
    exit;
} 

# If elevation needed, start new process
If (-NOT ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator))
{
  # Relaunch as an elevated process:
  Start-Process powershell.exe "-File",('"{0}"' -f $MyInvocation.MyCommand.Path),"$Args runas" -Verb RunAs
  exit
}

# You should modify '$Ports' for your applications 
$Ports = (22,80,443,8080)

# Check WSL ip address
wsl hostname -I | Set-Variable -Name "WSL"
$found = $WSL -match '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}';
if (-not $found) {
  echo "WSL2 cannot be found. Terminate script.";
  exit;
}

# Remove and Create NetFireWallRule
Remove-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock';
if ($Args[0] -ne "delete") {
  New-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock' -Direction Outbound -LocalPort $Ports -Action Allow -Protocol TCP;
  New-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock' -Direction Inbound -LocalPort $Ports -Action Allow -Protocol TCP;
}

# Add each port into portproxy
$Addr = "0.0.0.0"
Foreach ($Port in $Ports) {
    iex "netsh interface portproxy delete v4tov4 listenaddress=$Addr listenport=$Port | Out-Null";
    if ($Args[0] -ne "delete") {
        iex "netsh interface portproxy add v4tov4 listenaddress=$Addr listenport=$Port connectaddress=$WSL connectport=$Port | Out-Null";
    }
}

# Display all portproxy information
netsh interface portproxy show v4tov4;

# Give user to chance to see above list when relaunched start
If ($Args[0] -eq "runas" -Or $Args[1] -eq "runas") {
  Write-Host -NoNewLine 'Press any key to close! ';
  $null = $Host.UI.RawUI.ReadKey('NoEcho,IncludeKeyDown');
}

It suddenly does not work. It's not catching any of the wsl's IP. I believe it is my problem. Any ideas?

# result of wsl hostname -I
172.19.249.200 172.18.0.1 172.17.0.1
# result of this script
Listen on ipv4:             Connect to ipv4:

Address         Port        Address         Port
--------------- ----------  --------------- ----------
0.0.0.0         10000       192.168.42.226  10000
0.0.0.0         3000        192.168.42.226  3000
0.0.0.0         5000        192.168.42.226  5000

Solved (not knowing what exactly why):

# shutdown wsl first at cmd
wsl --shutdown
# run this script
./wsl2-network.ps1
# run wsl and restart ssh inside
sudo service ssh restart

Works but only for a minute. The connection suddenly closes after a short while

I have separate normal and administrator user on Windows, so I can't run wsl as normal user and firewall/portproxy rules as administrator. I haven't found a way where this is possible.

@woensug-choi Just add $WSL = $WSL.split(" ")[0] after $WSL variable definition.
@demfabris You must run any long-running live WSL process like service. sudo service ssh start for example.

Trying to use the script at startup of my pc with Task Schedule (without user login)

But it seems that wsl hostname -I returns nothing or an empty string, so the script exits again.

When running the script manually, it works. Any help?

Hello I am completely new to powershell. What should I do if I want to remove a proxy?
i.e. from the example from the first comment, what if I want to remove only

0.0.0.0 5000 192.168.42.226 5000

@chorongi I think this will work.
netsh interface portproxy delete v4tov4 listenport=5000 listenaddress=0.0.0.0

reference:
https://learn.microsoft.com/en-us/windows-server/networking/technologies/netsh/netsh-interface-portproxy#delete-v4tov4

I've added the following conditional to prevent an error on initial run.

# Remove and Create NetFireWallRule
$firewallRule = Get-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock' -ErrorAction SilentlyContinue;

if ($firewallRule) {
    Remove-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock';
}

For me, after countless hours of troubleshooting, I discovered that if you've tried using netsh interface portproxy add v4tov4 to set up port forwarding but it doesn't seem to work, it might be because the IP Helper service isn't running.

To resolve this, ensure the service is started by running:
net start iphlpsvc