In the previous tip we illustrated how WMI can ping multiple computers in a very fast way. So today, let’s wrap the code into a reusable PowerShell function. It can ping one or many computers with lightning speed.
Here’s the function code:
function Test-OnlineFast { param ( [Parameter(Mandatory)] [string[]] $ComputerName, $TimeoutMillisec = 1000 ) # convert list of computers into a WMI query string $query = $ComputerName -join "' or Address='" Get-WmiObject -Class Win32_PingStatus -Filter "(Address='$query') and timeout=$TimeoutMillisec" | Select-Object -Property Address, StatusCode }
Now it’s super easy to ping computers with a timeout of your choice:
PS> Test-OnlineFast -ComputerName microsoft.com, google.de Address StatusCode ------- ---------- google.de 0 microsoft.com 11010
A status code of “0” indicates a response: the system is online. Any other status code indicates failure.
By default, Test-OnlineFast uses a timeout of 1000 milliseconds, so when a machine does not respond, it waits a maximum of 1 second. You can change this timeout via -TimeoutMilliseconds. The more time you grant, the longer the command will take. You should therefore use a timeout that is as small as possible, while still allowing enough time for responding systems to send a response.
Another time factor to consider is DNS resolution: if DNS resolution is slow, or cannot resolve a name, this adds to the overall time it takes. With IP addresses, this slowdown does not occur.
Here is an example that pings 200 IP addresses and takes just a few seconds:
PS> $ComputerName = 1..255 | ForEach-Object { "10.62.13.$_" } PS> Test-OnlineFast -ComputerName $ComputerName Address StatusCode ------- ---------- 10.62.13.1 11010 10.62.13.10 0 10.62.13.100 0 10.62.13.101 11010 10.62.13.102 11010 (...)
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