Windows PowerShell, and an old-school command line tool favorite, collided today when I brainlessly typed the following:

PS C:\> ping computer1,computer2
Bad parameter computer2

This didn’t work, and as quickly as I realized my mistake, I thought, I’m going to have to fix it so ping can accept multiple computers.

There’s a couple ways I can do this, but my idea was to create an advanced function to do the work. I did that, but before I share the function, we should discuss what we could have done. We could have simply made an alias named ping that would run the Test-Connection cmdlet, a cmdlet that can handle a comma-separated list of computer names. Here’s an example of creating the alias and then using it to ping multiple computers.

PS C:\> New-Alias -Name ping -Value Test-Connection
PS C:\> ping computer1,computer2

Source        Destination     IPV4Address      IPV6Address                              Bytes    Time(ms)
------        -----------     -----------      -----------                              -----    --------
TOMMYMS PC... computer1       10.10.10.30                                              32       1
TOMMYMS PC... computer2       10.10.10.31                                              32       1
TOMMYMS PC... computer1       10.10.10.30                                              32       1
TOMMYMS PC... computer2       10.10.10.31                                              32       1
TOMMYMS PC... computer1       10.10.10.30                                              32       1
TOMMYMS PC... computer2       10.10.10.31                                              32       1
TOMMYMS PC... computer1       10.10.10.30                                              32       2
TOMMYMS PC... computer2       10.10.10.31                                              32       2

The reason this works is because of command precedence. If an alias and a command line tool share the same name, the alias will always run when the name is entered.

Well, this wasn’t quite want I wanted. I thought instead, I would make a wrapper around Test-Connection, called Test-TMConnection that would include a switch parameter (-Ping) that would return the standard ping results. I’ll dump in the function below and then we can walk though what it does.

Function Test-TMConnection {
    [CmdletBinding()]
    Param (
        [Parameter(Mandatory=$true)]
        [string[]]$ComputerName,

        [switch]$Ping
    )

    Begin {
    } # End Begin

    Process {
        If ($Ping) {
            ForEach ($Computer in $ComputerName) {
                ping $Computer
            }
        } Else {
            Test-Connection -ComputerName $ComputerName
        }
    } # End Process
} # End Function

Here’s how this works: The function is called by entering Test-TMConnection, the -ComputerName parameter, and then either one computer name, or a comma-separated list of computers. If the -Ping parameter is not used, it will run the standard Test-Connection cmdlet against the computer(s), like we saw in the alias example above. If -Ping is included, it will loop though the computers, using each one with ping. Here’s an example that includes the -Ping parameter.

PS C:\> Test-TMConnection -ComputerName computer1,computer2 -Ping

Pinging computer1.mydomain.com [10.10.10.30] with 32 bytes of data:
Reply from 10.10.10.30: bytes=32 time=2ms TTL=121
Reply from 10.10.10.30: bytes=32 time=1ms TTL=121
Reply from 10.10.10.30: bytes=32 time=1ms TTL=121
Reply from 10.10.10.30: bytes=32 time=1ms TTL=121

Ping statistics for 10.10.10.30:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 1ms, Maximum = 2ms, Average = 1ms

Pinging computer2.mydomain.com [10.10.10.31] with 32 bytes of data:
Reply from 10.10.10.31: bytes=32 time=1ms TTL=121
Reply from 10.10.10.31: bytes=32 time=2ms TTL=121
Reply from 10.10.10.31: bytes=32 time=1ms TTL=121
Reply from 10.10.10.31: bytes=32 time=1ms TTL=121

Ping statistics for 10.10.10.31:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 1ms, Maximum = 2ms, Average = 1ms

Important: Keep in mind, that if you were to use something like this, that you’ll be giving up other parameters that are included with ping and Test-Connection. This includes -t with ping, and -Count, and -Source with Test-Connection. In the end, the ping alias might be the better option.