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function Get-Ipv4SubnetInfo {
<#
.SYNOPSIS
Get subnet information.
.DESCRIPTION
This function will return basic subnet information if given an IP address as well as either
a subnet mask, or a mask length.
.EXAMPLE
Get-Ipv4SubnetInfo -IPAddress '10.10.10.1' -SubnetMask '255.255.0.0'
.EXAMPLE
Get-Ipv4SubnetInfo -IPAddress '192.168.0.4' -MaskLength 16
.NOTES
Author: Øyvind Kallstad
Date: 28.04.2015
Version: 1.0
#>
[CmdletBinding(DefaultParameterSetName = 'SubnetMask')]
param (
[Parameter()]
[IPAddress] $IPAddress = ([System.Net.NetworkInformation.NetworkInterface]::GetAllNetworkInterfaces() | Where-Object {$_.OperationalStatus -eq 'Up' -and $_.NetworkInterfaceType -ne [System.Net.NetworkInformation.NetworkInterfaceType]::Loopback}).GetIPProperties().UnicastAddresses.Address.ToString(),
[Parameter(ParameterSetName = 'SubnetMask')]
[IPAddress] $SubnetMask = ([System.Net.NetworkInformation.NetworkInterface]::GetAllNetworkInterfaces() | Where-Object {$_.OperationalStatus -eq 'Up' -and $_.NetworkInterfaceType -ne [System.Net.NetworkInformation.NetworkInterfaceType]::Loopback}).GetIPProperties().UnicastAddresses.IPv4Mask,
[Parameter(ParameterSetName = 'MaskLength')]
[ValidateRange(0,32)]
[int] $MaskLength
)
function ConvertTo-IPAddressUInt32 {
param (
[Parameter()]
[ValidateNotNullOrEmpty()]
[string] $IPAddress
)
try {
$ip = [IPAddress]::Parse($IPAddress)
$ipBytes = $ip.GetAddressBytes()
[System.Array]::Reverse($ipBytes)
$output = [BitConverter]::ToUInt32($ipBytes,0)
}
catch {
Write-Warning $_.Exception.Message
}
Write-Output $output
}
function ConvertTo-IPAddress {
param (
[Parameter()]
[ValidateRange([System.UInt32]::MinValue, [System.UInt32]::MaxValue)]
[uint32] $IPAddress
)
try {
$ipBytes = [BitConverter]::GetBytes($IPAddress)
[System.Array]::Reverse($ipBytes)
}
catch {
Write-Warning $_.Exception.Message
}
Write-Output ([IPAddress]$ipBytes)
}
function Get-IPv4AddressClass {
[CmdletBinding()]
param (
[Parameter(Position = 0)]
[IPAddress] $IPAddress
)
$ipBinary = ($IPAddress.GetAddressBytes() | ForEach-Object {[Convert]::ToString($_,2).PadLeft(8, '0') }) -join ''
switch -Regex ($ipBinary) {
'^1111' {$class = 'E';break}
'^1110' {$class = 'D';break}
'^110' {$class = 'C';break}
'^10' {$class = 'B';break}
'^0' {$class = 'A';break}
}
Write-Output $class
}
function Test-Ipv4IsPrivate {
[CmdletBinding()]
param (
[Parameter(Position = 0)]
[IPAddress] $IPAddress
)
$private = $false
$ipBinary = ($IPAddress.GetAddressBytes() | ForEach-Object {[Convert]::ToString($_,2).PadLeft(8, '0') }) -join ''
if (($ipBinary -match '^1100000010101000') -or ($ipBinary -match '^101011000001') -or ($ipBinary -match '^0000101')) {
$private = $true
}
Write-Output $private
}
if ($PSCmdlet.ParameterSetName -eq 'SubnetMask') {
# convert the subnetmask to uint32
$smUint32 = ConvertTo-IPAddressUInt32 -IPAddress $SubnetMask
# calculate mask length (CIDR) by converting the subnetmask to binary and counting the 1s
$SubnetMask.GetAddressBytes() | ForEach-Object {$cidr += [Convert]::ToString($_,2)}
$MaskLength = $cidr.TrimEnd('0').Length
}
else {
# create the subnetmask from the mask length, and convert to uint32
$smUint32 = [Convert]::ToUInt32($(('1' * $MaskLength).PadRight(32, '0')), 2)
$SubnetMask = ConvertTo-IPAddress -IPAddress $smUint32
}
# convert the IP address
$ipUint32 = ConvertTo-IPAddressUInt32 -IPAddress $IPAddress
# calculate the network and broadcast addresses of the subnet
$networkAddress = $ipUint32 -band $smUint32
$broadcastAddress = $ipUint32 -bor ((-bnot $smUint32) -band [UInt32]::MaxValue)
# calculate the first and the last address in the subnet
$firstIP = $networkAddress + 1
$lastIP = $broadcastAddress - 1
$usableAddresses = $lastIP - $networkAddress
Write-Output ([PSCustomObject] [Ordered] @{
NetworkAddress = (ConvertTo-IPAddress -IPAddress $networkAddress)
SubnetMask = $SubnetMask
FirstAddress = (ConvertTo-IPAddress -IPAddress $firstIP)
LastAddress = (ConvertTo-IPAddress -IPAddress $lastIP)
BroadcastAddress = (ConvertTo-IPAddress -IPAddress $broadcastAddress)
UsableAddresses = $usableAddresses
MaskLength = $MaskLength
AddressClass = (Get-IPv4AddressClass -IPAddress $IPAddress)
IsPrivate = (Test-Ipv4IsPrivate -IPAddress $IPAddress)
})
}
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