ARP to IP lookup PowerShell script

arp-to-ip-lookup-powershell.ps1

# Gets the IP address of a computer via the MAC address. This will only work on LAN
# segments. By default we'll scan the ARP table, but then defer to an IP scan to
# as needed.
#
# Usage: $returnIpAddress = GetIPFromMAC "12-43-de-52-a9-99" "192.168."
# Pass in the mac address with dashes (-) as the first parameter
# Pass in an IP address with the last number missing, be sure to include the trailing "."
# Be sure to check the value if $returnIpAddress -eq $null to see if a value was actually returned
#
#EDIT:Added functionality to check consecutive network segment numbers 20170727
function Get-IPFromMAC {
  Param (
      [string] $macAddress, 
      [string] $networkSegment
  )
  #will handle mac addresses with normal seperator characters
  $macaddress = (($macaddress.Replace(":","-")).Replace(" ","-")).Replace(".","-")

  Write-Host "Searching for $macAddress in network segment $networkSegment..."
  $ip = arp -a | Select-String $macAddress |% { $_.ToString().Trim().Split(" ")[0] }
  if ($ip -eq $null) 
  {
	Write-Host "$macAddress not found in ARP table, deep scan starting..."
    for($c = 44; $c -lt 47; $c++)#customize with consecutive net segment numbers
    {
          for ($i = 1; $i -lt 255; $i++) 
          {
              $ipAddr = $networkSegment + $c + "." + $i
              #Write-host "Pinging " $ipAddr
              ping "$ipAddr" -n 1 -l 1 -4 -w 90 | Out-Null
              $ip = arp -a "$networkSegment$i" | Select-String $macAddress |% { $_.ToString().Trim().Split(" ")[0] }
              if ($ip -ne $null) 
              {
		          Write-Host "Found $macAddress during deep scan, IP: $ip"
                  break
              }
          }
      } 
  }
  return $ip
}

#MacAddress Device Rename
Write-Host "Getting Ip-Address from MAC Address" 
$ipAddress = GetIPFromMac -macAddress $macAddress -networkSegment $networkSegment
Write-Host "Found IP Address: $ipAddress" 

BTW this saved my @$$ today. Having to look up IPs assigned to macs over and over as the IPs are changing after firmware updates. Saved my sanity.