Error handling - PowerShell script - powershell

Question

I have the following powershell script that cycles through a list of hostnames and changes the DNS settings for the active interfaces:
$servers = Get-Content C:\users\kevin.todd\desktop\serverlist.txt
foreach($server in $servers)
{
Write-Host "Connect to $server..."
$nics = Get-WmiObject Win32_NetworkAdapterConfiguration -ComputerName $server -ErrorAction Inquire | Where{$_.IPEnabled -eq "TRUE"}
$newDNS = "10.100.10.81","10.100.10.82"
foreach($nic in $nics)
{
Write-Host "`tExisting DNS Servers " $nic.DNSServerSearchOrder
$x = $nic.SetDNSServerSearchOrder($newDNS)
if($x.ReturnValue -eq 0)
{
Write-Host "`tSuccessfully Changed DNS Servers on " $server
}
else
{
Write-Host "`tFailed to Change DNS Servers on " $server
}
}
}
The problem is on some hosts I get the following error:
Get-WmiObject : The RPC server is unavailable. (Exception from
HRESULT: 0x800706BA) At C:\Documents and
Settings\user1\desktop\changednsserver.ps1:20 char:26
+ $nics = Get-WmiObject <<<< Win32_NetworkAdapterConfiguration
-ComputerName $server -ErrorAction Inquire | Where{ $_.IPEnabled -eq
"TRUE"}
+ CategoryInfo : InvalidOperation: (:) [Get-WmiObject],
COMException
+ FullyQualifiedErrorId :
GetWMICOMException,Microsoft.PowerShell.Commands.GetWmiObjectCommand
Existing DNS Servers You cannot call a method on a null-valued
expression. At C:\Documents and
Settings\user1\desktop\changednsserver.ps1:30 char:42
+ $x = $nic.SetDNSServerSearchOrder <<<< ($newDNS)
+ CategoryInfo : InvalidOperation:
(SetDNSServerSearchOrder:String) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
And I'm asked the following question by Powershell:
The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
[Y] Yes [A] Yes to All [H] Halt Command [S] Suspend [?] Help
(default is "Y"):
I would like the script to just answer A - Yes to all and continue running the script. The problem is it just halts the script until I manually enter "A". How can I have it automatically answer and continue?

Answer 1

Well the short answer is to not tell it to stop in the first place:
$nics = Get-WmiObject Win32_NetworkAdapterConfiguration -ComputerName $server -ErrorAction Inquire | Where{$_.IPEnabled -eq "TRUE"}
Try:
$nics = Get-WmiObject Win32_NetworkAdapterConfiguration -ComputerName $server -ErrorAction SilentlyContinue | Where{$_.IPEnabled -eq "TRUE"}

Answer 2

If you need to see where Errors occur, you have also a possibility to define an error variable using the switch
-ErrorVariable $<variable>
If errors occur in a foreach loop, the Error variable will be an array of error messages you can later analyze by querying the defined error variable with an array index echo $<EVariable>[<index>]
it would be something like echo $MyErrorArray[0] to get the first occurred error in that array.
An elegant way would be to have all that added to a textbox/combobox for log purposes but the coice of error handling ananalyzing is yours.