Final Super-Fast Ping Command

Revisiting the Test-Online Fast Function

In the previous tip series, we developed a new function called Test-OnlineFast that can ping multiple computers in record time. For some reason, the final version of this function did not include the pipeline support we promised. Here is the complete function again for you:

function Test-OnlineFast
{
    param
    (
        # make parameter pipeline-aware
        [Parameter(Mandatory,ValueFromPipeline)]
        [string[]]
        $ComputerName,

        $TimeoutMillisec = 1000
    )

    begin
    {
        # use this to collect computer names that were sent via pipeline
        [Collections.ArrayList]$bucket = @()
    
        # hash table with error code to text translation
        $StatusCode_ReturnValue = 
        @{
            0='Success'
            11001='Buffer Too Small'
            11002='Destination Net Unreachable'
            11003='Destination Host Unreachable'
            11004='Destination Protocol Unreachable'
            11005='Destination Port Unreachable'
            11006='No Resources'
            11007='Bad Option'
            11008='Hardware Error'
            11009='Packet Too Big'
            11010='Request Timed Out'
            11011='Bad Request'
            11012='Bad Route'
            11013='TimeToLive Expired Transit'
            11014='TimeToLive Expired Reassembly'
            11015='Parameter Problem'
            11016='Source Quench'
            11017='Option Too Big'
            11018='Bad Destination'
            11032='Negotiating IPSEC'
            11050='General Failure'
        }
    
    
        # hash table with calculated property that translates
        # numeric return value into friendly text

        $statusFriendlyText = @{
            # name of column
            Name = 'Status'
            # code to calculate content of column
            Expression = { 
                # take status code and use it as index into
                # the hash table with friendly names
                # make sure the key is of same data type (int)
                $StatusCode_ReturnValue[([int]$_.StatusCode)]
            }
        }

        # calculated property that returns $true when status -eq 0
        $IsOnline = @{
            Name = 'Online'
            Expression = { $_.StatusCode -eq 0 }
        }

        # do DNS resolution when system responds to ping
        $DNSName = @{
            Name = 'DNSName'
            Expression = { if ($_.StatusCode -eq 0) { 
                    if ($_.Address -like '*.*.*.*') 
                    { [Net.DNS]::GetHostByAddress($_.Address).HostName  } 
                    else  
                    { [Net.DNS]::GetHostByName($_.Address).HostName  } 
                }
            }
        }
    }
    
    process
    {
        # add each computer name to the bucket
        # we either receive a string array via parameter, or 
        # the process block runs multiple times when computer
        # names are piped
        $ComputerName | ForEach-Object {
            $null = $bucket.Add($_)
        }
    }
    
    end
    {
        # convert list of computers into a WMI query string
        $query = $bucket -join "' or Address='"
        
        Get-WmiObject -Class Win32_PingStatus -Filter "(Address='$query') and timeout=$TimeoutMillisec" |
        Select-Object -Property Address, $IsOnline, $DNSName, $statusFriendlyText
    }
    
}

Testing Test-OnlineFast: Pinging Computers

Let’s first check how Test-OnlineFast works. Here are some examples. Let’s first ping a number of computers. You can use both computer names and IP addresses:

 
PS> Test-OnlineFast -ComputerName google.de, powershellmagazine.com, 10.10.10.200, 127.0.0.1

Address                Online DNSName                Status           
-------                ------ -------                ------           
127.0.0.1                True DESKTOP-7AAMJLF        Success          
google.de                True google.de              Success          
powershellmagazine.com   True powershellmagazine.com Success          
10.10.10.200            False                        Request Timed Out

Let’s now ping an entire IP segment. The below example was taken from our public hotel WLAN (make sure you adjust the IP range to the network you are located in):

 
PS> $iprange = 1..200 | ForEach-Object { "192.168.189.$_" }

PS> Test-OnlineFast -ComputerName $iprange

Address         Online DNSName                            Status           
-------         ------ -------                            ------           
192.168.189.200   True DESKTOP-7AAMJLF.fritz.box          Success          
192.168.189.1     True fritz.box                          Success          
192.168.189.134   True PCSUP03.fritz.box                  Success          
192.168.189.29    True fritz.repeater                     Success          
192.168.189.64    True android-6868316cec604d25.fritz.box Success          
192.168.189.142   True Galaxy-S8.fritz.box                Success          
192.168.189.65    True mbecker-netbook.fritz.box          Success          
192.168.189.30    True android-7f35f4eadd9e425e.fritz.box Success          
192.168.189.10   False                                    Request Timed Out
192.168.189.100  False                                    Request Timed Out
192.168.189.101  False                                    Request Timed Out 
(...)

The amazing thing is the tremendous speed. Pinging an entire subnet takes only a few seconds.

Discover PowerShell Conference EU 2018

Do you know PowerShell Conference EU 2018, taking place April 17-20 in Hanover, Germany? If you are an advanced PowerShell professional, you shouldn’t miss this year’s agenda: www.psconf.eu: Hover over a session to view its abstract.

With 45 international top speakers including PowerShell inventor Jeffrey Snover, 80 sessions, and workshops, this event is much more than just a conference. It is a one-of-a-kind Advanced PowerShell Training and a very unique opportunity to meet friendly PowerShell gurus, get authoritative answers to even the trickiest PowerShell questions, and bring home fresh ideas.

This conference is not profit-driven, and all speakers volunteer. The delegate fee basically covers venue, food and drinks throughout the conference, evening events with grand dinner, and workshops.

Just don’t wait too long: this unique event is limited to 300 delegates, with 265 seats already taken by the time of this writing. Visit http://www.powershellmagazine.com/2018/02/09/powershell-conference-eu-2018/ for more details, or www.powershell.love for a quick impression of last year.

ReTweet this Tip!