Check your ip/computername with nslookup in powershell

Nslookup is a great tool for testing and troubleshooting. However, if you need to check a large range of IP/Computername in mass, nslookup is not the better choice. So, this below script could help you to do the same in powershell. (Download script)

#
#  NSLookup
#
#  by F.Richard 2011-05
#


# ***********************************************

Function NSlookup {
 Param($hostname)
 #$iphostEntry = [System.Net.Dns]::GetHostEntry($hostname) 
 # Rexolve obsolete but better than GetHostEntry
 $iphostEntry = [System.Net.Dns]::Resolve($hostname) 
 $line = $iphostEntry.HostName 

 $strSeparator = ";"
 foreach ($addr in $iphostEntry.AddressList) { 
  $line = $line + $strSeparator + $Addr.IPAddressToString 
  $strSeparator = "|"
 }  

 $strSeparator = ";"
 foreach ($alias in $iphostEntry.aliases) { 
  $line = $line + $strSeparator + $alias 
  $strSeparator = "|"
 } 

 return $line
}



# ***********************************************

Function TestFile {
 Param(
 [String] $strFilename,
 [String] $strCurDir
 ) 
 if ($strFilename) {
  $strCurDir = $(if ($strCurDir) {$strCurDir} else {if ($MyInvocation.MyCommand.CommandType -eq "Function") {(Get-Location).Path} else {Split-Path -parent $MyInvocation.MyCommand.Path} })
  If ((Test-Path("$strFilename")) -eq $False){
   If ($strFilename.ToUpper().Contains($strCurDir.ToUpper()) ) {
    Write-Host "ERROR: file $strFilename NOT exist"
    return
   } Else {
    If ((Test-Path("$strCurDir\$strFilename")) -eq $False){
     Write-Host "ERROR: file $strFilename NOT exist"
     Write-Host "ERROR: file $strCurDir\$strFilename NOT exist"
     return
    } Else {
     $strFilename = "$strCurDir\$strFilename"
    }
   }
  }
  return $strFilename
 }
}


# ***********************************************

Function GetFileIntoArr {
 Param(
 [String] $strFilename,
 [String] $strCurDir, 
 [Ref]$arrFile, 
 [String] $strComment
 ) 
 $strComment = $(if ($strComment) {$strComment} else {"#"})
 $strCurDir = $(if ($strCurDir) {$strCurDir} else {if ($MyInvocation.MyCommand.CommandType -eq "Function") {(Get-Location).Path} else {Split-Path -parent $MyInvocation.MyCommand.Path} })
 
 $retFilename = TestFile -strFilename $strFilename -strCurDir $strCurDir
 if ($retFilename) {
  $Content = Get-Content "$retFilename"
  Foreach ($line in $Content) {
   $comment = $False
   If ($line.Trim().length -gt 0) { # take only line with data and without # at begininng of the line
    # if we do not want to use comment 
    If ($strComment -eq "#") {
     If ($line.substring(0,1) -eq "#") {
      $comment = $True
     }   
    }
    If ($comment -eq $False) {
     # Get Search & Replace
     $arrFile.Value += $line.Trim()
    }
   }
  }
  return $True
 } else {
  return $False
 }
}

# ***********************************************

#
# MAIN PROGRAM
#

# Verify Arguments Number
If($Args.Count -lt 2) {
 Write-Host "Syntax:"$MyInvocation.MyCommand.Name "inputfilename outputfilename"
 Write-Host " Example:"$MyInvocation.MyCommand.Name" 'inputfile.txt' 'outputfile.txt' "
 Write-Host " Example:"$MyInvocation.MyCommand.Name" -inputfile 'inputfile.txt' -outputfile 'outputfile.txt' "
 Write-Host 
 Break 
}

$inputfile = $args[0]
$outputfile = $args[1]
$date = get-date -format "yyyy-MM-dd"
$Content = "#Date;Computer;Hostname;IP`r`n"
$Content | Out-File -encoding ASCII $outputfile 
[Array] $arrComputers = @( ) 

if ($inputfile) {
        if (!(GetFileIntoArr -strFilename $inputfile -arrFile ([Ref]$arrComputers))) { 
  Break 
 }
} else {
 Write-Host "ERROR: you need a filename.txt as second parameter inputfile"
 Break 
}
Foreach ($computer in $arrComputers) {
 $nslookup = NSlookup($computer)
 $line = $date + ";" + $computer + ";" + $nslookup 
 #+ "`r`n"
 Write-Host $line
 $line | Out-File -append -encoding ASCII $outputfile 
}    

Example of Result:

#Date;Computer;Hostname;IP
2011-06-01;COMPUTER1;computer1.dns1.my.net;192.1.1.45;COMPUTER1.dns2.my.net
2011-06-01;COMPUTER2;COMPUTER2.si.net;192.1.1.100
2011-06-01;COMPUTER3;COMPUTER3.si.net;192.1.1.101
2011-06-01;COMPUTER4;COMPUTER4.si.net;192.1.102