Networking

Retrieve environment variable values from a remote system with WMI

Back in October I shared with you a way to retrieve environment variables with a script titled Using Environment variables inside a VBScript script. The script worked like a champ and got me through several tight binds in gathering information, hopefully it has for you as well. However, it has one flaw… it doesn’t work on a remote system! In fact, it only works on the system that the script is running on.

So, I had to recently go back to the drawing board and create a script and series of functions that would work remotely so that I could wrap it in a function to gather information from a bunch of servers. I also Learned a thing or two in the process!

First, The script uses the Win32_environment classes in WMI and this class returns ALL envirnment variables for ALL users. That threw me for a loop when I saw multiple PATH environment variables– some that were different. Second, The search is case sensitive without using the SQL % wildcards (I didn’t need them, so implementing that is left up to you the reader.)

I have the three functions I wrote, that are really variations of one another below. Just add them to your script and call them with the appropriate values and you should be in business!

Function RemoteAllEnvironmentVariables(ServerName)
     ‘Lists all environment variables on the remote system
     Dim objWMIService, colItems, objItem
 
     RemoteAllEnvironmentVariables = “”
     Set objWMIService = GetObject(”winmgmts:\\” & ServerName & “\root\cimv2″)
     Set colItems = objWMIService.ExecQuery(”Select * from Win32_Environment”)
     For Each objItem in colItems
         RemoteAllEnvironmentVariables = RemoteAllEnvironmentVariables & objitem.name & “: ” & objItem.VariableValue & VbCrLf
     Next
End Function

Function RemoteAllEnvironmentVariablesVariations(ServerName, VariableName)
     ‘Lists all environment variables on the remote system, along with every case variation
     Dim objWMIService, colItems, objItem
 
     RemoteAllEnvironmentVariablesVariations = “”
     Set objWMIService = GetObject(”winmgmts:\\” & ServerName & “\root\cimv2″)
     Set colItems = objWMIService.ExecQuery(”Select * from Win32_Environment”)
     For Each objItem in colItems
         If UCase objItem.name) = UCase(VariableName) Then
         RemoteAllEnvironmentVariablesVariations = RemoteAllEnvironmentVariablesVariations & objitem.name & “: ” & objItem.VariableValue & VbCrLf
         End If
     Next
End Function

 
Function RemoteEnvironmentVariable(ServerName, VariableName)
     ’Lists all environment variables on the remote system, exactly as you typed it in the function call.
     Dim objWMIService, colItems, objItem
 
     RemoteEnvironmentVariable = “”
     Set objWMIService = GetObject(”winmgmts:\\” & ServerName & “\root\cimv2″)
     Set colItems = objWMIService.ExecQuery(”Select * from Win32_Environment Where Name = ‘” & VariableName & “‘”)
     For Each objItem in colItems
         RemoteEnvironmentVariable = objItem.VariableValue
     Next
End Function

Pinging a remote computer from another remote computer using the WMI Win32_PingStatus class in VBScript

I recently began working on trying to figure out ways to troubleshoot real problems with a VBScript and give me some diagnostic information about the current state of the environment. As I build this script I plan on sharing pieces of it bit by bit with you, my readers. I also wanted to get back to writing some WMI scripts that will help you all do your jobs more efficiently. Lastly, I wanted to begin building a “toolbox” script that you could use to write your own scripts. These are the goals I’m tracking toward in my next series of posts that contain VBScript code. Now onto this script…

The first piece of troubleshooting a problem, in my opinion, is ensuring that a communication path exists between two systems. Duh! However, simply pinging the systems individually from your desktop isn’t a good test… it only tests the your computer can communicate with the two systems, not that they can communicate with each other!

This script simply uses our friend WMI to make a call a remote computer requesting that computer ping another computer. Simple enough, but invaluable because how many times have you had to login to a remote computer to check if it can connect to a system? Now you don’t have to… you can do it from a script!

The script uses the Win32_PingStatus class in WMI. Essentially, it will only work on Windows XP and newer (Sorry, Windows 2000 and older doesn’t support the WMI class we need.) and the user executing the script will likely need to be an administrator on the system that is being called (but not necessarily being pinged). For further information on this class you can reference the Win32_PingStatus documentation.

Now lets get to the script!

 ‘Use a remote computer to ping another remote computer
Option Explicit 
‘Change the SourceServer and RemoteServer Strings below to servernames or IP addresses for you.
wscript.Echo RemotePing(”SourceServer”, “RemoteServer”)
wscript.Echo “Done!”

Function RemotePing( SourceComputer, DestinationComputer)

 Dim strComputer1, strComputer2
 Dim objWMIService, colItems, objItem

 strComputer1 = SourceComputer
 strComputer2 = DestinationComputer

 On Error Resume Next
  ’ error control block
  Set objWMIService = GetObject(”winmgmts:{impersonationLevel=impersonate}//” & strComputer1 & “\root\cimv2″)
  Set colItems = objWMIService.ExecQuery (”Select * from Win32_PingStatus ” & “Where Address = ‘” & strComputer2 & “‘”)
  For Each objItem in colItems
      If objItem.StatusCode = 0 Then
          RemotePing = strComputer1& “: Reply received from ” & strComputer2 & ” in ” & objItem.ResponseTime & ” ms.”         
      Else
       RemotePing = “Error pinging ” & strComputer2 & ” from ” & strComputer1 & “. The status code returned was :” & objItem.StatusCode
      End If
  Next
 On Error GoTo 0
End function

As always, this code works perfectly. However, sometimes the formatting of the blog breaks the code if you copy and paste it into your editor. So, if you’d like to not type or troubleshoot any syntax errors due to the copy and paste problems– I’ve provided the code for download, plus example output files  from my final tests for you. You’ll find the code and other files available for download from my website’s (www.websystemsadministration.com) File Depot under the ITKE Blog Scripts category. Enjoy and happy scripting!

Useful site: Tons of free books online… did I mention free?

I like free stuff. Who doesn’t? And with the price of technology books you can imagine I was amazed when I found a pretty cool site recently, Scribd, that allows you to upload electronic documents. They then add this document to the database they have and make it search-able. Plus, you can search the database for specific subjects or words.

Not only are regular people uploading books and documents, but there are publisher’s uploading books. Sometimes they are just excerpts, but sometimes they are entire books as well like:

ASP Programming for the Absolute Beginner
Beginning ASP NET 3 5 in C Sharp 2008 From Novice to Professional
MSPress Exam 70-284 Implementing and managing Exchange server 2003

There’s even a CCIE Study Guide and my personal favorite the VBScript Complete Reference !

 And Many Many more… so stroll on over there and see what you can find!

Enjoy!

How to find a lost router password for most routers

In this installment, I thought I’d take a quick break from VBScript and give you a little networking information I stumbled upon.

Recently, at my current job site we had a situation where the client didn’t know the router password because a series of network administrators had left and the password was simply “lost in the shuffle”. Of course, you all know this is not a good situation to be in if you need to preform network maintenance or want to upgrade a portion of the network somehow.

Of course the only thing we could hope for was that the previous network administrators had NOT been security minded and left the router passwords blank, or that there had not been a console password configured… so started off with trying to figure out what the factory default passwords were for the particular router we were working with at the moment. In our search I found a really awesome resource, that will be invaluable if this ever happens to you here. This site has all the major player’s factory default router passwords in a database, simply select your manufacturer and click find password. Where you are then presented with the known factory default router passwords for specific models from the manufacturer! Awesomeness!

Well, as luck would have it, the last guy didn’t follow standard security practices and this site had the default router password we needed. We were able to get in and get the job done– and change the password when we were done. Plus, after such a scare, the client is sure to not let this happen again.

Now, we got lucky (and so did the client after years of service from the router with default passwords), but what if you need to get into a router and the password has been set to something other than default? Well, this situation is a bit harder– but not impossible. You need to see if you can get onto the console of the router, most major manufacturers have a mechanism for you to plug directly into a router with a serial cable and change settings. Hopefully, this will NOT have a console password– if it does try the defaults, just in case.

Once in, get a dump or output of the configuration. Then you will need to follow the manufacturers method to change the password. Should the console connection not have enough security to change the passwords– you may have to set the router to factory defaults. Be sure if you do this you have the configuration completely and you are prepared to rebuild it. I would not recommend you do this unless you have either done this before or you have 24/7/365 support and have the support folks on the phone while you do it.

Here is my recommendation (and I’ll probably get many security folks commenting differently) , but assuming the router is in a secured place, (a hall closet or the CEO’s office does not count) and locked away so only authorized people can get to it, I almost always leave no password on the console for cases just like this one I’ve mentioned.

Hopefully this helps someone out there and good luck!

Creating text files using the Scripting.FileSystemObject with VBScript

Well, I didn’t expect the cat to get out of the bag quite so quickly! (Congratulations go out to Stoinov for getting the correct answer I was thinking of so very quickly!) So while he’s been sleeping during his night, which seems to be my day… I thought I’d throw together a quick “Write a text file” script together for you all. (A little trivia for you all in the United States, that I found hard to believe when I learned it… VBScript, and VB for that matter, is in English regardless of where you are in the world. If you’re on a Japanese system writing VBScript, your using the same language as us folks in the United States. Talk about portable code!)

Back to the matter at hand, this script doesn’t do anything terribly spectacular– by itself. All it does is opens (or creates) a text file named what you call it where you specify. The heart of the script is the WriteTextFile () function, which accepts two pieces of data; a full path to a file name and the data you want to write. That’s it! But—- this function will let you write logs, CSV (Comma Separated Value) files or any other form of text file from any type of script for which you choose to use it!

A quick little note on the access method I hard coded into the script. You  will notice three constants used ForReading, ForWriting, and ForAppending these are there so you could change the mode easily without having to go to the documentation for the OpenTextFile Method of the Scripting.FileSystemObject and figure out what numbers to use to change the access method. you simply just need to change the access method from ForReading on the OpenTextFile line of the script to accomplish this task. An excerpt of the Microsoft documentation for the values and descriptions are listed below, for your reference.

Notice it has a ForAppending attribute? If you wanted to … say log a series of collected values over a number of calls to the script you would have to change the access method to appending, however, keep in mind that ForAppending assumes the file already exists and you will receive an error if it doesn’t.

So, here is the script to write a file…

Option Explicit
Dim Error

Error = WriteTextFile (”c:\test.txt”, “I created a text file with VBScript!”)
If Error = 0 Then
    WScript.Echo “File Written Correctly.”
Else
    WScript.Echo”Error number ” & Error & ” occurred.”
End If

Function WriteTextFile (OutputFile, Data)
    Dim wrtlog, fso
 
    ’these are constants for the OpenTextFile method’s file access modes
    Const ForReading = 1, ForWriting = 2, ForAppending = 8
  
    On Error Resume Next
    Set fso = CreateObject(”Scripting.FileSystemObject”)
    Set wrtlog = fso.OpenTextFile (OutputFile, ForWriting , true)

    wrtlog.WriteLine(Data)
    WriteTextFile = Err.Number ‘You can use Err.Description here to debug.
End Function

That’s it. Small, but a VERY powerful tool to add to your tool belt in scripting.

As always, this code works perfectly. However, sometimes the formatting of the blog breaks the code if you copy and paste it into your editor. So, if you’d like to not type or troubleshoot any syntax errors due to the copy and paste problems– I’ve provided the code for download, plus example output files  from my final tests for you. You’ll find the code and other files available for download from my website’s (www.websystemsadministration.com) File Depot under the ITKE Blog Scripts category. Enjoy and happy scripting!