functions/Get-IPAddressesInSubnet.ps1
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<#
.SYNOPSIS Lists all IP addresses within a specified subnet using CIDR notation. .DESCRIPTION The Get-IPAddressesInSubnet function generates a complete list of all possible IP addresses within a given subnet specified in CIDR notation. It supports all subnet masks from /0 to /32. .PARAMETER Subnet Specifies the subnet in CIDR notation (e.g., "192.168.0.0/24") .EXAMPLE Get-IPAddressesInSubnet -Subnet "192.168.1.0/24" Lists all IP addresses in the 192.168.1.0/24 subnet (256 addresses) .EXAMPLE Get-IPAddressesInSubnet -Subnet "10.0.0.0/30" Lists all IP addresses in the 10.0.0.0/30 subnet (4 addresses) .INPUTS String .OUTPUTS System.String[] Returns an array of IP addresses as strings .NOTES Author: Iman Edrisian Version: 1.0.0 Requires PowerShell 5.1 or higher .LINK https://github.com/imanedr/psnetworking #> function Get-IPAddressesInSubnet { [CmdletBinding()] param ( # Parameter to specify the subnet in CIDR notation (e.g. 192.168.0.0/24) [Parameter(Mandatory)] [string] $Subnet ) # List of subnet masks for all possible CIDR values (from /0 to /32) $bitMask = @('0.0.0.0', '128.0.0.0', '192.0.0.0', '224.0.0.0', '240.0.0.0', '248.0.0.0', '252.0.0.0', '254.0.0.0', '255.0.0.0', '255.128.0.0', '255.192.0.0', '255.224.0.0', '255.240.0.0', '255.248.0.0', '255.252.0.0', '255.254.0.0', '255.255.0.0', '255.255.128.0', '255.255.192.0', '255.255.224.0', '255.255.240.0', '255.255.248.0', '255.255.252.0', '255.255.254.0', '255.255.255.0', '255.255.255.128', '255.255.255.192', '255.255.255.224', '255.255.255.240', '255.255.255.248', '255.255.255.252', '255.255.255.254', '255.255.255.255') # Split the Subnet parameter into the network ID and CIDR value [System.Net.IPAddress]$netID, [int]$cidr = $Subnet -split "/" # Calculate the network mask based on the CIDR notation [System.Net.IPAddress]$mask = $bitMask[$cidr] # Calculate the network ID based on the network mask and the IP address $netID = $mask.Address -band $netID.Address # Get the octets of the network ID and the network mask $netIdOctets = $netID.GetAddressBytes() $maskOctets = $mask.GetAddressBytes() # Calculate the wildcard mask based on the network mask $wildCardMaskOctets = $maskOctets.ForEach({255 - $_}) $ordered = [System.Collections.Specialized.OrderedDictionary]::new() # Loop through each octet of the network ID to calculate all the IP addresses in the subnet for ($i= $netIdOctets[0]; $i -le ($netIdOctets[0] -bor $wildCardMaskOctets[0]); $i++){ for ($j= $netIdOctets[1]; $j -le ($netIdOctets[1] -bor $wildCardMaskOctets[1]); $j++){ for ($k= $netIdOctets[2]; $k -le ($netIdOctets[2] -bor $wildCardMaskOctets[2]); $k++){ for ($l= $netIdOctets[3]; $l -le ($netIdOctets[3] -bor $wildCardMaskOctets[3]); $l++){ # Write the calculated IP address to the output stream $ip = "$i.$j.$k.$l" $ordered.Add($ip, $ip) } } } } Return $ordered.Values } |