internal/functions/Get-SubnetAddress.ps1
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<#
.SYNOPSIS Converts an IPv4 subnet address in CIDR notation (ie, 192.168.0.0/24) into a collection of [ipaddress] objects. .DESCRIPTION Converts an IPv4 subnet address in CIDR notation (ie, 192.168.0.0/24) into a collection of [ipaddress] objects. .PARAMETER Subnet IPv4 subnet address in CIDR notation (ie, 192.168.0.0/24) .EXAMPLE Get-SubnetAddress "192.168.0.0/24" .NOTES Website: https://powershell.org/forums/topic/ip-address-math/ Copyright: (c) 2014 Dave Wyatt License: MIT https://opensource.org/licenses/MIT Used with permission: https://twitter.com/msh_dave/status/1037475306381094913 #> function Get-SubnetAddress { [CmdletBinding()] param ( [Parameter(Mandatory)] [string] $Subnet ) $ipaddress = $null # Validating the string format here instead of in a ValidateScript block allows us to use the # $ipaddress and $matches variables without having to perform the parsing twice. if ($Subnet -notmatch '^(?<address>\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/(?<mask>\d{1,2})$') { throw "Subnet address '$Subnet' does not match the expected CIDR format (example: 192.168.0.0/24)" } if (-not [ipaddress]::TryParse($matches['address'], [ref]$ipaddress)) { throw "Subnet address '$Subnet' contains an invalid IPv4 address." } $maskDecimal = [int]$matches['mask'] if ($maskDecimal -gt 30) { throw "Subnet address '$Subnet' contains an invalid subnet mask (must be less than or equal to 30)." } $hostBitCount = 32 - $maskDecimal $netMask = [UInt32]0xFFFFFFFFL -shl $hostBitCount $hostMask = -bnot $netMask $networkAddress = (Get-UInt32FromIPAddress -IPAddress $ipaddress) -band $netMask $broadcastAddress = $networkAddress -bor $hostMask for ($address = $networkAddress + 1; $address -lt $broadcastAddress; $address++) { Get-IPAddressFromUInt32 -UInt32 $address } } |