Question: I'm running Ubuntu 18.04 from Windows Bash:

```
uname -a
Linux DESKTOP-M87DGAS 4.4.0-17134-Microsoft #112-Microsoft Thu Jun 07 22:57:00 PST 2018 x86_64 x86_64 x86_64 GNU/Linux

```

I need to open some port with:

```
sudo ufw allow 22/tcp

```

But I get the following error:

> 
> ERROR: initcaps  
> 
>  [Errno 2] iptables v1.6.1: can't initialize iptables table `filter': Table 
>  does not exist (do you need to insmod?)  
> 
>  Perhaps iptables or your kernel needs to be upgraded.
> 
> 
> 

I get the same error by typing:

```
iptables -L

```

I've already upgrade my kernel with:

```
sudo apt-get update
sudo apt-get full-upgrade

```

I've tried to reboot the system but it didn't work.

How can I initiate the iptable filter?

Answer: 
According to the Microsoft WSL page on github.com, iptables isn't supported.

<https://github.com/Microsoft/WSL/issues/767>

There is a uservoice page for requesting support at

<https://wpdev.uservoice.com/forums/266908-command-prompt-console-bash-on-ubuntu-on-windo/suggestions/32025199-support-iptables>
Windows restrict that command in WSL without authorization from administrator.

You just have to run WSL on `CMD/Powershell/Ubuntu.exe` as administator, then try this command again:

```
sudo iptables -L -v

```

I tested on WSL v1, but it should also work on WSL v2.