.NET DNS class powershell background job possible?

问题

I found this script which I modified a bit to take in the hostnames from a file:

http://tompaps.blogspot.com/2015/04/verify-forward-and-reverse-dns-records.html

It pretty much iterates through each name in the file, pings it, converts the returned IP into a string and performs a reverse lookup on the IP. It works, but when I have 600+ machines to go through performance is no bueno. I know with test-connection there's an -asjob parameter I can use to run asynchronous jobs which does the forwardlookup job in seconds but does anyone know a way to mimic this behavior for the reverse lookup?

I found a post on this forum suggesting you can do something similar using the .NET process class but I've just been working with Powershell for a few months and can't seem to decipher the MSDN docs.

回答1:

You can wrap it up in a scriptblock and do Start-Job in a foreach loop to do the following for forward and reverse lookup:

$ComputerName= ‘computername here’
[System.Net.Dns]::GetHostAddresses(“$ComputerName”).IPAddressToString

$ComputerIPAddress = ‘that computer ip here'
[System.Net.Dns]::GetHostEntry($ComputerIPAddress).HostName

For example

$whateverlist = Get-Content .\yourlistofservers.txt

# or you can..

$whateverlist = @"
machine1
machine2
machine3
etc
"@

$Scriptblock = {
param($machine);

    $pingOk = Test-Connection -cn $machine -BufferSize 16 -Count 1 -EA silentlyContinue
        if ($pingOk)
        {

            # Do whatever if it responds to pinging
            # Maybe store the property in a list, put it out to a file etc.

            [System.Net.Dns]::GetHostAddresses(“$machine”).IPAddressToString



            # Use whatever method you like to get IP of the computer, even use the above output.
            # Me being lazy:
            $ip = [System.Net.Dns]::GetHostAddresses(“$machine”).IPAddressToString


            [System.Net.Dns]::GetHostEntry($ip).HostName

        }
}

# Then you can get the job, do whatever. Do it in a foreach for best results.
foreach ($machine in $whateverlist)
{
    Start-Job -ScriptBlock $Scriptblock -ArgumentList $machine
}


# To crack open the eggs and get the goodies:
Receive-Job * -Keep | Out-File ".\whatevermanijustworkhere.txt"

Here's a clean copy:

$whateverlist = Get-Content .\yourlistofservers.txt

$whateverlist = @"
machine1
machine2
machine3
etc
"@

$Scriptblock = {
param($machine);

    $pingOk = Test-Connection -cn $machine -BufferSize 16 -Count 1 -EA silentlyContinue
        if ($pingOk)
        {
            $ip = [System.Net.Dns]::GetHostAddresses(“$machine”).IPAddressToString
            $ip

            [System.Net.Dns]::GetHostEntry($ip).HostName

        }
}


foreach ($machine in $whateverlist)
{
    Start-Job -ScriptBlock $Scriptblock -ArgumentList $machine
}

Receive-Job * -Keep | Out-File ".\whatevermanijustworkhere.txt"

Source:

https://adsecurity.org/?p=305

回答2:

In case anyone's interested I ended up doing the following:

   Import-Module 'C:\Users\Lia Cha\Documents\Windows Powershell\Modules\Invoke-Parallel.psm1'

   $machines = Get-Content C:\work\hostnames.txt

   Invoke-Parallel -InputObject $machines -RunspaceTimeout 10 -Throttle 10 -ErrorAction SilentlyContinue -ScriptBlock {
   $obj = "" | Select ComputerName,Ping,IPNumber,ForwardLookup,ReverseLookup,Result  
   $obj.ComputerName = $_  

  # ping each host  
  if(Test-Connection $_ -quiet -Count 1){  
       $obj.Ping = "OK"  
 $obj.Result = "OK"  
  }  
  else{  
       $obj.Ping = "Error"  
 $obj.Result = "Error"  
  }  

  # lookup IP addresses of the given host  
  [array]$IPAddresses = [System.Net.Dns]::GetHostAddresses($obj.ComputerName) | ?{$_.AddressFamily -eq "InterNetwork"} | %{$_.IPAddressToString}  

  # caputer count of IPs  
  $obj.IPNumber = ($IPAddresses | measure).count  

  # if there were IPs returned from DNS, go through each IP  
    if($IPAddresses){  
 $obj.ForwardLookup = "OK"  

    $IPAddresses | %{  
         $tmpreverse = $null  

            # perform reverse lookup on the given IP  
         $tmpreverse = [System.Net.Dns]::GetHostEntry($_).HostName 
         if($tmpreverse){  

                 # if the returned host name is the same as the name being processed from the input, the result is OK  
              if($tmpreverse -ieq $obj.ComputerName){  
                   $obj.ReverseLookup += "$_ : OK `n"  
              }  
              else{  
                   $obj.ReverseLookup += "$_ different hostname: $tmpreverse `n"  
                   $obj.Result = "Error"  
              }  
         }  
         else{  
              $obj.ReverseLookup = "No host found"  
              $obj.Result = "Error"  
         }  
 }  
  }  
  else{  
       $obj.ForwardLookup = "No IP found"  
       $obj.Result = "Error"  
  }  

  # return the output object  
  $obj | ft -AutoSize | out-string -width 4096 | out-file c:\work\Results.txt -Append}

This ran over 450+ machines in about 4mins.

来源：https://stackoverflow.com/questions/36205922/net-dns-class-powershell-background-job-possible