runasadmin.ps1

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope LocalMachine

wslnet.ps1

$WslInstanceName = 'Ubuntu-20.04'
$WindowsHostIPAddress = '192.168.255.1'
$UbuntuInstanceIPAddress = '192.168.255.2'
$SubnetMaskNumberOfBits = 24

$WslFirewallRuleName = 'WSL'
$WslNetworkInterfaceName = 'vEthernet (WSL)'
$UbuntuNetworkInterfaceName = 'eth0'

# Ensure the "vEthernet (WSL)" network adapter has been created by starting WSL.
Write-Host 'Ensure WSL network exists...'
wsl --distribution "$WslInstanceName" /bin/false
Write-Host 'WSL network exists'

# All inbound traffic from Ubuntu through Windows firewall and assign a static IP address to the "vEthernet (WSL)"
# network adapter in Windows.
Write-Host 'Configuring Windows host network...'
Start-Process 'powershell.exe' -Verb RunAs -Wait -ArgumentList '-ExecutionPolicy Bypass', @"
-Command & {
  Write-Host 'Checking firewall...'
  If (-Not (Get-NetFirewallRule -Name '$WslFirewallRuleName' -ErrorAction SilentlyContinue)) {
    Write-Host 'Configuring firewall...'
    New-NetFirewallRule -Name '$WslFirewallRuleName' -DisplayName '$WslFirewallRuleName' -InterfaceAlias '$WslNetworkInterfaceName' -Direction Inbound -Action Allow
    Write-Host 'Finished configuring firewall'
  }
  Else {
    Write-Host 'Already configured firewall'
  }
 
  Write-Host 'Checking network interface...'
  If (-Not (Get-NetIPAddress -InterfaceAlias '$WslNetworkInterfaceName' -IPAddress '$WindowsHostIPAddress' -PrefixLength $SubnetMaskNumberOfBits  -ErrorAction SilentlyContinue)) {
    Write-Host 'Configuring network interface...'
    New-NetIPAddress -InterfaceAlias '$WslNetworkInterfaceName' -IPAddress '$WindowsHostIPAddress' -PrefixLength $SubnetMaskNumberOfBits
    Write-Host 'Finished configuring network interface'
  }
  Else {
    Write-Host 'Already configured network interface'
  }
}
"@
Write-Host 'Finished configuring Windows host network'

# Assign a static IP address to the "eth0" network interface in Ubuntu.
Write-Host 'Configuring Ubuntu instance network...'
wsl --distribution "$WslInstanceName" --user root /bin/sh -c "ifconfig eth0 0"
wsl --distribution "$WslInstanceName" --user root /bin/sh -c "ip ro del default"
wsl --distribution "$WslInstanceName" --user root /bin/sh -c "if !(ip address show dev $UbuntuNetworkInterfaceName | grep -q $UbuntuInstanceIPAddress/$SubnetMaskNumberOfBits); then ip address add $UbuntuInstanceIPAddress/24 brd + dev $UbuntuNetworkInterfaceName; fi"
wsl --distribution "$WslInstanceName" --user root /bin/sh -c "ip ro add default via $WindowsHostIPAddress dev eth0"
wsl --distribution "$WslInstanceName" --user root /bin/sh -c "echo nameserver $WindowsHostIPAddress > /etc/resolv.conf"
Write-Host 'Finished configuring Ubuntu instance network'