Finding connected network adapters

    PowerTip : Show ‘up’ physical adapters

    Question: You want to see which physical network adapters on your Windows 8.1 computer using Windows PowerShell. How can you do this?

    Answer: Use the -physical parameter with the Get-NetAdapter function and filter for a status of up. This technique appears here:

    It is pretty easy to use NetSh to retrieve information about the connection status of network adapters. To do so, I use the following command:

    One of the problems, from a management perspective, is that the command returns text. Therefore, if I need to parse the text to pull out specific information, such as the Interface Index number, or the Name of the adapter, then I am going to have to resort to writing a complicated regular expression pattern. If all I need to do is to obtain the information because I am writing to a log file as text, then the command works great, and is the lowest common denominator - I can use it all the way back to Windows 2000 days.

    I can even run the netsh commands from within the Windows PowerShell console. This appears in the figure that follows.

    1. get-wmiobject win32\_networkadapter|select netconnectionid, name, InterfaceIndex, netconnectionstatus

    The command and the output from the command appear in the figure that follows.

    The difference is that instead of plain text, the command returns objects that can be further manipulated. Therefore, while the above command actually returns the network connection status of all network adapters, the NetSh command only returns the ones that are connected. If I filter on a netconnectionstatus of 2 I can return only the connected network adapters. The command becomes this one (this is a single line command that I broke at the pipeline character for readability):

    1. get-wmiobject win32\_networkadapter -filter "netconnectionstatus = 2"|
    3. selectnetconnectionid,name,InterfaceIndex,netconnectionstatus

    The command and output appear in the figure that follows.

    image047.png

    If the desire is to obtain the connection status of more than just network adapters that are connected, then the task will require writing a script to do a lookup. The lookup values appear in the table that follows:

    The Get-NetworkAdapterStatus.ps1 script requires at least Windows PowerShell 2.0 which means that it will run on Windows XP SP3 and above.

    Get-NetworkAdapterStatus.Ps1

    1. <#
    3.  .Synopsis
    4.   Produces a listing of network adapters and status on a local or remote machine.
    6.  .Description
    7.   This script produces a listing of network adapters and status on a local or remote machine.
    9.  .Example
    10.   Get-NetworkAdapterStatus.ps1 -computer MunichServer
    11.   Lists all the network adapters and status on a computer named MunichServer
    13.  .Example
    14.   Get-NetworkAdapterStatus.ps1
    15.   Lists all the network adapters and status on local computer
    17.  .Inputs
    18.   [string]
    19.  .OutPuts
    20.   [string]
    22.  .Notes
    23.   NAME: Get-NetworkAdapterStatus.ps1
    25.   AUTHOR: Ed Wilson
    27.   LASTEDIT: 1/10/2014
    29.   KEYWORDS: Hardware, Network Adapter
    31.  .Link
    33.   Http://www.ScriptingGuys.com
    35. #Requires -Version 2.0
    37. #>
    39. Param(
    40.  [string]$computer=$env:COMPUTERNAME
    41. ) #end param
    43. functionGet-StatusFromValue
    44. {
    45. switch($SV)
    47.  0 { " Disconnected" }
    48.  1 { " Connecting" }
    49.  2 { " Connected" }
    50.  3 { " Disconnecting" }
    51.  4 { " Hardware not present" }
    52.  5 { " Hardware disabled" }
    53.  6 { " Hardware malfunction" }
    54.  7 { " Media disconnected" }
    55.  8 { " Authenticating" }
    56.  9 { " Authentication succeeded" }
    57.  10 { " Authentication failed" }
    58.  11 { " Invalid Address" }
    59.  12 { " Credentials Required" }
    60.  Default { "Not connected" }
    61.  }
    63. } #end Get-StatusFromValue function
    65. # \*\*\* Entry point to script \*\*\*
    67. Get-WmiObject-Classwin32\_networkadapter-computer$computer|
    68. Select-ObjectName, @{LABEL="Status";
    70. EXPRESSION={Get-StatusFromValue$\_.NetConnectionStatus}}

    When I run the Get-StatusFromValue.ps1 script, in the Windows PowerShell ISE, I see the output achieved here.

    On Windows 8 and above the NetAdapter module contains the Get-NetAdapter function. To see the status of all network adapters, use the Get-NetAdapter function with no parameters. The command appears here:

      The output from this command appears here.

      image051.png

      I can reduce the output to only physical adapters by using the -physical parameter. This command appears here.

      If I only want to see the physical network adapters that are actually up, I pipeline the results to the where-object. This command appears here.