Get IP Data

I was doodling in PowerShell this morning and ended up with what I hope is a useful function to retrieve IP configuration information, sort of like IPCONFIG, but using WMI. The beauty is that I can connect to remote machines and the output is an object which leads to all sorts of possibilities.

My function is called Get-IPData.

Function Get-IPData {
#this function assumes admin credentials
[cmdletBinding()]
Param(
    [Parameter(Position=0,ValueFromPipeline=$True,ValueFromPipelineByPropertyName=$True)]
    [ValidateNotNullOrEmpty()]
    [Alias("name")]
    [string[]]$computername=$env:computername
)

Process {
    ForEach ($computer in $computername) {
        Write-Verbose "Querying $($computer.ToUpper())"
        Try 
        {
            #get NICS that are IP and DHCP enabled
            Get-WMIObject -Class win32_networkadapterconfiguration -computername $Computer `
            -Filter "IPEnabled='TRUE' AND DHCPEnabled='TRUE'" -ErrorAction "Stop" | 
            Select Description,DNSHostname,
            @{Name="IPAddress";Expression={$_.IPAddress[0]}},
            @{Name="SubnetMask";Expression={$_.IPSubnet[0]}},
            @{Name="DefaultGateway";Expression={$_.DefaultIPGateway[0]}},DNSDomain,
            @{Name="PrimaryDNS";Expression={$_.DNSServerSearchOrder[0]}},DHCPServer,
            @{Name="DHCPLease";Expression={$_.ConvertToDateTime($_.DHCPLeaseObtained)}},
            @{Name="DHCPExpires";Expression={$_.ConvertToDateTime($_.DHCPLeaseExpires)}},
            @{Name="DHCPTimeToLive";Expression={ $_.ConvertToDateTime($_.DHCPLeaseExpires) - (Get-Date)}},
            MACAddress,
            @{Name="Speed";Expression={
            #use an Associators Of query to get the NIC
              $nic=Get-WmiObject -query "associators of {Win32_NetworkAdapterConfiguration.Index=$($_.index)}" -computername $computer
              $nic.Speed
              }}
        } #close Try
        Catch
        {
            Write-Warning "Failed to retrieve IP configuration from $($computer.ToUpper())"
            Write-Warning $_.Exception.Message

        } #close Catch
    } #close ForEach
 } #close Process
} #end function

The function takes computernames as a parameter, uses WMI to get the NetworkAdapterConfiguration for IP and DHCP enabled adapters.

Get-WMIObject -Class win32_networkadapterconfiguration -computername $Computer -Filter "IPEnabled='TRUE' AND DHCPEnabled='TRUE'" -ErrorAction "Stop"

The rest of the function simply selects key properties including another WMI query to get the associated adapater's speed. Because some items like IP address are stored as arrays, I use a hash table expression to return the first item only.

PS C:\> get-ipdata

Description    : Atheros AR8131 PCI-E Gigabit Ethernet Controller (NDIS 6.20)
DNSHostname    : SERENITY
IPAddress      : 172.16.10.124
SubnetMask     : 255.255.0.0
DefaultGateway : 172.16.10.254
DNSDomain      : jdhitsolutions.local
PrimaryDNS     : 172.16.10.1
DHCPServer     : 172.16.10.1
DHCPLease      : 3/10/2011 7:30:01 AM
DHCPExpires    : 3/13/2011 8:30:01 AM
DHCPTimeToLive : 2.22:43:15.9650056
MACAddress     : 00:26:9E:C7:09:76
Speed          : 1000000000

I started to do my usual code polishing but then I realized this might be a good exercise for you. The function works as is with some limited error handling in a Try/Catch block. But there are several areas for improvement or enhancement. You might want to:

• Add support for alternate credentials
• Add comment based help
• Add support for running as a background job
• Create a graphical, WinForm/WPF version
• Add IPv6 information
• Add the average ping response time
• Add more adapter information

I'll leave the rest to you. This could be a nice warmup practice for the upcoming Scripting Games.

Download Get-IPData.ps1

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