Performing Networking Tasks

To get all IP addresses in use on the local computer, use the following command:

Get-WmiObject -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=TRUE -ComputerName . | Format-Table -Property IPAddress

The output of this command differs from most property lists, because values are enclosed in braces:

IPAddress

---------

{192.168.1.80}

{192.168.148.1}

{192.168.171.1}

{0.0.0.0}

To understand why the braces appear, use the Get-Member cmdlet to examine the IPAddress property:

PS> Get-WmiObject -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=TRUE -ComputerName . | Get-Member -Name IPAddress

TypeName: System.Management.ManagementObject#root\cimv2\Win32_NetworkAdapter

Configuration

Name MemberType Definition

---- ---------- ----------

IPAddress Property System.String[] IPAddress {get;}

The IPAddress property for each network adapter is actually an array. The braces in the definition indicate that IPAddress is not a System.String value, but an array of System.String values.

To display detailed IP configuration data for each network adapter, use the following command:

Get-WmiObject -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=TRUE -ComputerName .

The default display for the network adapter configuration object is a very reduced set of the available information. For in-depth inspection and troubleshooting, use Select-Object or a formatting cmdlet, such as Format-List, to specify the properties to be displayed.

If you are not interested in IPX or WINS properties—probably the case in a modern TCP/IP network—you can use the ExcludeProperty parameter of Select-Object to hide properties with names that begin with "WINS" or "IPX:"

Get-WmiObject -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=TRUE -ComputerName . | Select-Object -Property [a-z]* -ExcludeProperty IPX*,WINS*

This command returns detailed information about DHCP, DNS, routing, and other minor IP configuration properties.

You can perform a simple ping against a computer using by Win32_PingStatus. The following command performs the ping, but returns lengthy output:

Get-WmiObject -Class Win32_PingStatus -Filter "Address='127.0.0.1'" -ComputerName .

A more useful form for summary information a display of the Address, ResponseTime, and StatusCode properties, as generated by the following command. The Autosize parameter of Format-Table resizes the table columns so that they display properly in Windows PowerShell.

PS> Get-WmiObject -Class Win32_PingStatus -Filter "Address='127.0.0.1'" -ComputerName . | Format-Table -Property Address,ResponseTime,StatusCode -Autosize

Address   ResponseTime StatusCode
-------   ------------ ----------
127.0.0.1            0          0
A status code of 0 indicates a successful ping.

You can use an array to ping multiple computers with a single command. Because there is more than one address, use the ForEach-Object to ping each address separately:

"127.0.0.1","localhost","research.microsoft.com" | ForEach-Object -Process {Get-WmiObject -Class Win32_PingStatus -Filter ("Address='" + $_ + "'") -ComputerName .} | Select-Object -Property Address,ResponseTime,StatusCode

You can use the same command format to ping all of the computers on a subnet, such as a private network that uses network number 192.168.1.0 and a standard Class C subnet mask (255.255.255.0)., Only addresses in the range of 192.168.1.1 through 192.168.1.254 are legitimate local addresses (0 is always reserved for the network number and 255 is a subnet broadcast address).

To represent an array of the numbers from 1 through 254 in Windows PowerShell, use the statement 1..254. A complete subnet ping can be performed by generating the array and then adding the values onto a partial address in the ping statement:

1..254| ForEach-Object -Process {Get-WmiObject -Class Win32_PingStatus -Filter ("Address='192.168.1." + $_ + "'") -ComputerName .} | Select-Object -Property Address,ResponseTime,StatusCode

Note that this technique for generating a range of addresses can be used elsewhere as well. You can generate a complete set of addresses in this way:

$ips = 1..254 | ForEach-Object -Process {"192.168.1." + $_}

Earlier in this user's guide, we mentioned that you could retrieve general configuration properties by using Win32_NetworkAdapterConfiguration. Although not strictly TCP/IP information, network adapter information such as MAC addresses and adapter types can be useful for understanding what is going on with a computer. To get a summary of this information, use the following command:

Get-WmiObject -Class Win32_NetworkAdapter -ComputerName .

To assign the DNS domain for automatic name resolution, use the Win32_NetworkAdapterConfiguration SetDNSDomain method. Because you assign the DNS domain for each network adapter configuration independently, you need to use a ForEach-Object statement to assign the domain to each adapter:

Get-WmiObject -Class Win32_NetworkAdapterConfiguration -Filter IPEnabled=true -ComputerName . | ForEach-Object -Process { $_. SetDNSDomain("fabrikam.com") }

The filtering statement "IPEnabled=true" is necessary, because even on a network that uses only TCP/IP, several of the network adapter configurations on a computer are not true TCP/IP adapters; they are general software elements supporting RAS, PPTP, QoS, and other services for all adapters and thus do not have an address of their own.

You can filter the command by using the Where-Object cmdlet, instead of using the Get-WmiObject filter.

Get-WmiObject -Class Win32_NetworkAdapterConfiguration -ComputerName . | Where-Object -FilterScript {$_.IPEnabled} | ForEach-Object -Process {$_.SetDNSDomain("fabrikam.com")}

Modifying DHCP details involves working with a set of network adapters, just as the DNS configuration does. There are several distinct actions you can perform by using WMI, and we will step through a few of the common ones.

To create a network share, use the Win32_Share Create method:

(Get-WmiObject -List -ComputerName . | Where-Object -FilterScript {$_.Name -eq "Win32_Share"}).Create("C:\temp","TempShare",0,25,"test share of the temp folder")

You can also create the share by using net share in Windows PowerShell:

net share tempshare=c:\temp /users:25 /remark:"test share of the temp folder"

You can remove a network share with Win32_Share, but the process is slightly different from creating a share, because you need to retrieve the specific share to be removed, rather than the Win32_Share class. The following statement deletes the share "TempShare":

 (Get-WmiObject -Class Win32_Share -ComputerName . -Filter "Name='TempShare'").Delete()

Net share works as well:

PS> net share tempshare /delete
tempshare was deleted successfully.

The New-PSDrive cmdlets creates a Windows PowerShell drive, but drives created this way are available only to Windows PowerShell. To create a new networked drive, you can use the WScript.Network COM object. The following command maps the share \\FPS01\users to local drive B:

(New-Object -ComObject WScript.Network).MapNetworkDrive("B:", "\\FPS01\users")

The net use command works as well:

net use B: \\FPS01\users

Drives mapped with either WScript.Network or net use are immediately available to Windows PowerShell.