tak.Convert-PrefixLengthToMask.ps1
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function Convert-SubnetMask { <# .SYNOPSIS Convert a SubnetMask to PrefixLength or vice-versa. .DESCRIPTION Long description .EXAMPLE PS C:\> Convert-SubnetMask 24 255.255.255.0 This example converts the PrefixLength 24 to a dotted SubnetMask. .EXAMPLE PS C:\> Convert-SubnetMask 255.255.0.0 16 This example counts the relevant network bits of the dotted SubnetMask 255.255.0.0. .INPUTS [string] .OUTPUTS [string] .NOTES Logic from: https://d-fens.ch/2013/11/01/nobrainer-using-powershell-to-convert-an-ipv4-subnet-mask-length-into-a-subnet-mask-address/ #> [CmdletBinding()] param ( # SubnetMask to convert [Parameter(Mandatory)] $SubnetMask ) if($SubnetMask -as [int]) { [ipaddress]$out = 0 $out.Address = ([UInt32]::MaxValue) -shl (32 - $SubnetMask) -shr (32 - $SubnetMask) $out.IPAddressToString } elseif($SubnetMask = $SubnetMask -as [ipaddress]) { $SubnetMask.IPAddressToString.Split('.') | ForEach-Object { while(0 -ne $_){ $_ = ($_ -shl 1) -band [byte]::MaxValue $result++ } } $result -as [string] } } |