Powershell error "New-NetFirewallRule: The specified interface was not found on the system" when configuring Firewall rule for WSL

Problem

When executing the following command line in Powershell while configuring Firewall rules for WSL:

New-NetFirewallRule -DisplayName "WSL" -Direction Inbound -InterfaceAlias "vEthernet (WSL)" -Action Allow`

Some users may encounter this issue:

New-NetFirewallRule : The specified interface was not found on the system.

Cause

Most likely, the network interface name was changed from the default vEthernet (WSL) to something else, causing the command to fail.

Resolution

1. Execute the below command in Powershell to get the list of all network interfaces in the system:

   Get-NetAdapter -IncludeHidden

2. Find the actual name of the interface used by WSL (it will be one of the Hyper-V Virtual Ethernet Adapters)

   Note: if no device is displayed at all, you might need to reset your WSL configuration by clearing or removing the %UserProfile%.wslconfig file, performing wsl --shutdown, and then retrying the Get-NetAdapter command in PowerShell.

3. Replace vEthernet (WSL) in the New-NetFirewallRule... command with the actual interface name and execute it again: