Q:

PowerShell Multiple Input IP Addresses

I have an issue with multiple input in this code:
cls
Install-Module SNMP
Get-Command -Module SNMP

Write-Output ----------------------------------------
$IP = "192.168.15.1"
Write-Output ----------------------------------------
Write-Output "Selected IP is: $IP"
Write-Output ----------------------------------------

Invoke-SnmpWalk -IP $IP -Community public -OID .1.3.6.1.2.1.2.2.1.2  | Format-Table Data -AutoSize -HideTableHeaders | Out-File C:\NameP.ps1xml 

Get-Content C:\NameP.ps1xml  | Where { $_ -ne ""  } | Set-Content C:\NameP1.ps1xml 
$Ports = @(Get-Content C:\NameP1.ps1xml | Where-Object { $_.StartsWith("Unit") } )
$NumberOfports = @(Get-Content C:\NameP1.ps1xml | Where-Object { $_.StartsWith("Unit") } ).Count

Write-Output ----------------------------------------
Write-Output "Name ports: "$Ports  
Write-Output ----------------------------------------
Write-Output "Number of ports:  $NumberOfports"

This is for one IP address of switch and a I need to go through multiple switches of one production with different IP addresses for example 192.168.16.1, 192.168.17.1 suddenly with one script with list of IP or something like that. 
My output:
 CommandType     Name                                               Version    Source     
-----------     ----                                               -------    ------     
Function        Get-SnmpData                                       1.0.0.1    SNMP       
Function        Invoke-SnmpWalk                                    1.0.0.1    SNMP       
Function        Set-SnmpData                                       1.0.0.1    SNMP       
----------------------------------------
----------------------------------------
Selected IP is: 192.168.15.1
----------------------------------------
----------------------------------------
Name of ports: 
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 1                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 2                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 3                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 4                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 5                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 6                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 7                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 8                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 9                   
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 10                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 11                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 12                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 13                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 14                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 15                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 16                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 17                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 18                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 19                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 20                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 21                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 22                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 23                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 24                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 25                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 26                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 27                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 28                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 29                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 30                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 31                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 32                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 33                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 34                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 35                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 36                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 37                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 38                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 39                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 40                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 41                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 42                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 43                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 44                  
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 45 - no sfp inserted
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 46 - no sfp inserted
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 47 - no sfp inserted
Unit: 1 1000BASE-T RJ45 Gigabit Ethernet Frontpanel Port 48 - no sfp inserted
----------------------------------------
Number of ports:  48

I want this output for more IPs. Do you have any simple solution that would go through multiple IP addresses? 
Then I still work with these data. 
Thanks for every idea.

A:

Provide the multiple IP's as a "list",
Simply encapsulate the repeated code within a Foreach loop.

Thus:
Install-Module SNMP
Get-Command -Module SNMP
Write-Output ----------------------------------------
$IP = "192.168.15.1","192.168.17.1" # Add more to the list
Write-Output ----------------------------------------
Write-Output "Selected IP is: $IP"
Write-Output ----------------------------------------

$IP | % {
    Invoke-SnmpWalk -IP $_ -Community public -OID .1.3.6.1.2.1.2.2.1.2  | Format- 
    Table Data -AutoSize -HideTableHeaders | Out-File C:\NameP.ps1xml 

    Get-Content C:\NameP.ps1xml  | Where { $_ -ne ""  } | Set-Content 
    C:\NameP1.ps1xml 
    $Ports = @(Get-Content C:\NameP1.ps1xml | Where-Object { $_.StartsWith("Unit") } 
    )
    $NumberOfports = @(Get-Content C:\NameP1.ps1xml | Where-Object { 
    $_.StartsWith("Unit") } ).Count

    Write-Output ----------------------------------------
    Write-Output "Name ports: "$Ports  
    Write-Output ----------------------------------------
    Write-Output "Number of ports:  $NumberOfports"

} # End of ForEach

