Using ForEach-Object -Parallel on multiple Servers with Get-NetFirewallRule

Question

I am writing a code which is checking the firewall rules from multiple servers. Since we have alot servers here, i want to run my Script parallel on these servers. My script is kind of working. I get 510 firewall rules. Sadly its prints always the same 510 Firewall rules to the export.txt for each server.

Here is my code:

$servers = @("server1","server2", "server3") #only 3 server for testing

$line = @"
*******************************************************************************
*******************************************************************************
*******************************************************************************
*******************************************************************************
*******************************************************************************
"@
$cred = Get-Credential 
Clear-Content -Path "c:\temp\export.txt" -Force

$servers | ForEach-Object -Parallel {
    $error.Clear()
    $session = New-PSSession -ComputerName $PSItem -Credential $using:cred  -ErrorAction SilentlyContinue
    if ($error) {
            $CurrentServer = "The Server " + $PSItem + " is not reachable"
            $CurrentServer | Out-File -FilePath "c:\temp\export.txt" -Append
            $Errortext = $Error[0]
            $Errortext | Out-File -FilePath "c:\temp\export.txt" -Append
            $using:line | Out-File -FilePath "c:\temp\export.txt" -Append
            $error.Clear()
    } else {
            $CurrentServer = "Firewall Rules for Server " + $PSItem
            $Output = Invoke-Command -ScriptBlock {
                $Values = Get-NetFirewallRule | Select-Object DisplayName
                return $Values
            }
            $CurrentServer | Out-File -FilePath "c:\temp\export.txt" -Append
            $Output | Out-File -FilePath "c:\temp\export.txt" -Append
            $using:line | Out-File -FilePath "c:\temp\export.txt" -Append
    }
}

Any ideas how this can work? :)

Greetings!

I tried alot with ForEach -Parallel. Also tried something with Jobs but didnt get a result there.

I expect to see all Firewall Rules from each server in the export.txt

Answer 1

oh it was easier then i thought. Just needed to add -Session $session at the end of the brace } of the Invoke-Command -Scriptblock :)