Using Invoke-WmiMethod to set the DNS servers

In the last post I showed that there was an issue with the way the SetDNSServerSearchOrder of the Win32_NetworkAdapterConfiguration class worked

This would work

$nic = Get-WmiObject -Class Win32_NetworkAdapterConfiguration -Filter “Index=7”

but using Invoke-WmiMethod failed

After discussions with Bartek Bielawski (PowerShell MVP) and a bit more digging I found that for multiple DNS servers this would work

$dnsserver = “”, “”
Get-WmiObject -Class Win32_NetworkAdapterConfiguration  -Filter “Index=7” | Invoke-WmiMethod -Name SetDNSServerSearchOrder -ArgumentList (, $dnsserver)

Its necessary to create an array as the input argument  (, $variable) – its a unary array ie one element array

if you want to use just a single DNS server then you need to use the unary array trick twice – once when you create the variable and again when you use Invoke-wmimethod.  Messy but it works

$dnsserver = (,”″)
Get-WmiObject -Class Win32_NetworkAdapterConfiguration  -Filter “Index=7” | Invoke-WmiMethod -Name SetDNSServerSearchOrder -ArgumentList (, $dnsserver)


If you want to use the new CIM cmdlets in PowerShell v3 – its easy if you have multiple DNS servers

$dnsserver = “”, “”
Get-CimInstance -ClassName Win32_NetworkAdapterConfiguration -Filter “Index=7” | Invoke-CimMethod -MethodName SetDNSServerSearchOrder -Arguments @{DNSServerSearchOrder = $dnsserver}


for a single one we just need to create a unary array on the Arguments parameter
$dnsserver = “”
Get-CimInstance -ClassName Win32_NetworkAdapterConfiguration -Filter “Index=7” | Invoke-CimMethod -MethodName SetDNSServerSearchOrder -Arguments @{DNSServerSearchOrder = (,$dnsserver)}


This is not satisfactory because we have to adopt different techniques depending on the number of DNS servers we need to put into NIC property. This is NOT a PowerShell issue – it has to be a WMI issue because the IP address that we saw last time also takes an array and it was very happy with a single value.

Hopefully this is not something that will come up too often but be aware of these options when working with WMI methods

This entry was posted in Networking, PowerShell and WMI, PowerShell V2, PowerShell V3. Bookmark the permalink.

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