[Powershell] Try-Catch fails to catch an exception?

I was running a script that does WMI query and found that my try-catch-final statement seemed not working. The exception was still shown on console instead of handled by my catch block.

It turns out that exceptions are categorized into two groups, terminating exceptions and non-terminating exceptions. By default, try-catch intercepts only terminating exceptions. No surprisingly, get-WMIobject exceptions are non-terminating exceptions.

There are two ways to make it work. One is to make all exception terminating by below assignment:

$ErrorActionPreference = "Stop"; #Make all errors terminating


Remember to reset the preference at the end of your script as this is global.


$ErrorActionPreference = "Continue"


Or right after get-WMIobject statement, check the value of $?


if ($?){ 
        #processing block
}
else {
       throw $error[0].exception
}

Retrieving Terminal Server Configuration Settings Using Powershell

It was quite easy for Windows 2003 TS servers with Win32_TerminalServiceSetting WMI class, there are tons of documents on the Net. It took me some time, however, to find out that MS change the class considerably for Windows 2008.

It's now under a different name space root\cimv2\TerminalServices. It also requires you to specify an authentication flavour before you can gain access.

In short, you get info with below commands (w2k3 and w2k8 respectively):

gwmi Win32_TerminalServiceSetting -computername -namespace root/cimv2/TerminalServices -authentication 6

or

gwmi Win32_TerminalServiceSetting -computername [-namespace root/cimv2]

Enable LDAP over SSL Using Certificate Generated From A Different Machine

The procedure is pretty simple and well documented in KB 321051, so there is nothing special here. However the tricky part is you have to submit the request from the same DC in order to make LDAPS work because this way ensures you have the private key for the certificate.

In some cases, it could take quite a while to obtain a certificate so you want to submit the request way ahead of time - so long ahead of time that you may not have the hardware yet at the time you have to send the request.

A workaround is to submit the request from another machine - any other machine as long as you make the request right. Once you get the certifiate, install it on the requesting machine, then export it with private key, finally import onto your new DC.