Finding Active IP Addresses and Resolved Hostnames with PowerShell

# Continue to run script when an error occurs

$ErrorActionPreference = "SilentlyContinue"

# Process through the loop of IP addresses 1-254

1..254 | foreach -Process `

{

    # We're combining the contents of different objects, so create our own

    $obj = New-Object PSObject;

    # Perform the Ping using WMI

    $ping = get-WmiObject -Class Win32_PingStatus -Filter ("Address='10.10.2." + $_ + "'");

    # Put the IP Address into our object

    $obj | Add-Member NoteProperty IPAddress($ping.Address);

    # Take the Ping Status Code that is returned (0 = pingable)

    $obj | Add-Member NoteProperty StatusCode($ping.StatusCode);

    # If we can ping the address, let's try to resolve the hostname

    if($ping.StatusCode -eq 0)

    {

          # Record that the ping was successful

           $obj | Add-Member NoteProperty Status("Online");

        # Try to resolve the IP address to a hostname in DNS

        $dns = [System.Net.Dns]::GetHostByAddress($ping.Address);

           if($dns -ne $null)

           {

            # Add the resolved hostname to our collection

             $obj | Add-Member NoteProperty ResolvedHostName($dns.HostName);

           }

           else

           {

            # Couldn't resolve the IP address to a hostname

               $obj | Add-Member NoteProperty ResolvedHostName("");

           }

    }

    else

    {

        # Can't ping IP address, so mark host as offline

           $obj | Add-Member NoteProperty ResolvedHostName("");

           $obj | Add-Member NoteProperty Status("Offline");

    }

    # Write the collection out

    Write-Output $obj;

    # Cleanup DNS object

    $dns = $null;

}