Pinging with Powershell - Get a list of online servers

Just about every IT guy or girl on the planet has used ping countless of times. With Powershell those days are over: Meet Test-Connection. It works just as you would expect and similar to ping, the advantage being that you (by default) get an object of type "System.Management.ManagementObject#root\cimv2\Win32_PingStatus" back.

I wont go into details on how to use Test-Connection, there are plenty of ressources doing just that. But I recently discover a very cool way to use Test-Connection against a large number of servers. And as they say, A script is worth a thousand words:

function Check-Online
{
    param(
        $ComputerName
        )

    Begin
    {
        # put live servers into this list
        $Script:serverlist = @()
    }

    Process
    {
        If (Test-Connection -Count 1 -ComputerName  $_ -TimeToLive 5 -asJob | 
         Wait-Job |
         Receive-Job |
         ? { $_.StatusCode -eq 0 } )
        {
            $Script:serverlist += $_
        }
    }
    End
    {
        return $Script:serverlist
    }
}

# get computer names from hyper-v
$ComputerNames = Get-VM | Select-Object -ExpandProperty Name
# check which are online
$ComputerNames | Check-Online

Simply feed the Check-Online function a list of computernames (IPs should work just as well) and it will return a list of online servers within seconds.

I think credit for the original code goes to my Lumagate colleague Claus Nielsen who just happens to be a Powershell MVP.

Download script from Technet gallery.