PowerShell netsh inline command not working properly

Question

When I run

PS C:\WINDOWS\system32> wsl hostname -I
172.27.96.44
PS C:\WINDOWS\system32> netsh interface portproxy add v4tov4 listenport=3000 connectport=3000 connectaddress=172.27.96.44
PS C:\WINDOWS\system32> netsh interface portproxy show all

Listen on ipv4:             Connect to ipv4:

Address         Port        Address         Port
--------------- ----------  --------------- ----------
*               3000        172.17.218.173  3000

It works, the target address is accesible. But when I run

netsh interface portproxy add v4tov4 listenport=3000 connectport=3000 connectaddress=$(wsl hostname -I)

PS C:\WINDOWS\system32>  netsh interface portproxy show all

Listen on ipv4:             Connect to ipv4:

Address         Port        Address         Port
--------------- ----------  --------------- ----------
*               3000        172.27.96.44    3000

The target address is not accesible. It just doesn't respond. Even despite the fact that it is shown in the table. I tried string conversions e.g.

netsh interface portproxy add v4tov4 listenport=3000 connectport=3000 connectaddress=([string] (wsl hostname -I));

But it didn't help. Why it doesn't work even when the ip address is in the table?

Doug Maurer · Accepted Answer · 2021-10-16 15:16:13Z

4

If you take the output of your WSL command and a verbatim string of what you believe is the same value and compare the actual bytes with Format-Hex, you will see there is a difference.

$output = WSL hostname -I

$output | Format-Hex


           00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00000000   31 39 32 2E 31 36 38 2E 31 2E 36 38 20           192.168.1.68

VS

'192.168.1.68' | Format-Hex


           00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00000000   31 39 32 2E 31 36 38 2E 31 2E 36 38              192.168.1.68

So it's adding a value, a 20. I took a guess and it is indeed a space.

$output -replace '\s' | Format-Hex

           00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00000000   31 39 32 2E 31 36 38 2E 31 2E 36 38              192.168.1.68

So you can solve this various ways but as shown it can be as simple as.

$output = (WSL hostname -I) -replace '\s'

You can always test the contents of your variable. I regularly do something like this just for a sanity check. It would've definitely saved you here.

$output = WSL hostname -I

Write-Host "A$($output)A"

A192.168.1.68 A

answered Oct 16, 2021 at 15:16

Doug Maurer

8,9773 gold badges16 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

mklement0 Over a year ago

Nice sleuthing; "connectaddress=$((wsl hostname -I).Trim())" should do.

Doug Maurer Over a year ago

As well as "connectaddress=$((wsl hostname -I).Trimend())"

mklement0 Over a year ago

As an aside: This Gist contains function Debug-String, which may helpful; e.g., 'ab ' | Debug-String outputs ab· (the dot represents the trailing space). It can also represent non-ASCII-range characters as Unicode escape sequences with -UnicodeEscapes.

Collectives™ on Stack Overflow

PowerShell netsh inline command not working properly

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related