getIpSubnet.ps1 ca

getIpSubnet.ps1

# functions were pulled from
# https://www.itprotoday.com/powershell/working-ipv4-addresses-powershell
function ConvertTo-IPv4MaskString {
  <#
  .SYNOPSIS
  Converts a number of bits (0-32) to an IPv4 network mask string (e.g., "255.255.255.0").

  .DESCRIPTION
  Converts a number of bits (0-32) to an IPv4 network mask string (e.g., "255.255.255.0").

  .PARAMETER MaskBits
  Specifies the number of bits in the mask.
  #>
  param(
    [parameter(Mandatory=$true)]
    [ValidateRange(0,32)]
    [Int] $MaskBits
  )
  $mask = ([Math]::Pow(2, $MaskBits) - 1) * [Math]::Pow(2, (32 - $MaskBits))
  $bytes = [BitConverter]::GetBytes([UInt32] $mask)
  (($bytes.Count - 1)..0 | ForEach-Object { [String] $bytes[$_] }) -join "."
}

function Test-IPv4MaskString {
  <#
  .SYNOPSIS
  Tests whether an IPv4 network mask string (e.g., "255.255.255.0") is valid.

  .DESCRIPTION
  Tests whether an IPv4 network mask string (e.g., "255.255.255.0") is valid.

  .PARAMETER MaskString
  Specifies the IPv4 network mask string (e.g., "255.255.255.0").
  #>
  param(
    [parameter(Mandatory=$true)]
    [String] $MaskString
  )
  $validBytes = '0|128|192|224|240|248|252|254|255'
  $maskPattern = ('^((({0})\.0\.0\.0)|'      -f $validBytes) +
         ('(255\.({0})\.0\.0)|'      -f $validBytes) +
         ('(255\.255\.({0})\.0)|'    -f $validBytes) +
         ('(255\.255\.255\.({0})))$' -f $validBytes)
  $MaskString -match $maskPattern
}

function ConvertTo-IPv4MaskBits {
  <#
  .SYNOPSIS
  Returns the number of bits (0-32) in a network mask string (e.g., "255.255.255.0").

  .DESCRIPTION
  Returns the number of bits (0-32) in a network mask string (e.g., "255.255.255.0").

  .PARAMETER MaskString
  Specifies the IPv4 network mask string (e.g., "255.255.255.0").
  #>
  param(
    [parameter(Mandatory=$true)]
    [ValidateScript({Test-IPv4MaskString $_})]
    [String] $MaskString
  )
  $mask = ([IPAddress] $MaskString).Address
  for ( $bitCount = 0; $mask -ne 0; $bitCount++ ) {
    $mask = $mask -band ($mask - 1)
  }
  $bitCount
}


$params = @{
  "ComputerName" = "."
  "Class" = "Win32_NetworkAdapterConfiguration"
  "Filter" = "IPEnabled=TRUE"
}
$netConfigs = Get-WMIObject @params
foreach ( $netConfig in $netConfigs ) {
  for ( $i = 0; $i -lt $netConfig.IPAddress.Count; $i++ ) {
    if ( $netConfig.IPAddress[$i] -match '(\d{1,3}\.){3}\d{1,3}' ) {
  $ipString = $netConfig.IPAddress[$i]
  $ip = [IPAddress] $ipString
  $maskString = $netConfig.IPSubnet[$i]
  $mask = [IPAddress] $maskString
  $netID = [IPAddress] ($ip.Address -band $mask.Address)
  "IP address: {0}" -f $ip.IPAddressToString
  "Subnet mask: {0}" -f $mask.IPAddressToString
  "Network ID: {0}" -f $netID.IPAddressToString
  'Network ID+maskbit: {0}/{1}' -f $netID.IPAddressToString,(ConvertTo-IPv4MaskBits $mask.IPAddressToString)
    }
  }
}