VNCScan Network Troubleshooting (Part 1)

Introduction

VNCScan is a powerful tool that can you can use to administer most aspects of computer management.  The vast majority of our feedback says that we’ve done a great job so far of making the tool as intuitive and easy to use as possible for a program with this large of a feature set.  We’ve looked at how competing products have bloated their options to almost usability and have been trying hard not to let that happen to VNCScan. 

With that being said, there are some common pitfalls that you can run into with any application that needs to access remote computers in an administrative role and this article series is here to help you though some of the most common of them.

If you have a suggestion for this series on VNCScan Network Troubleshooting, please leave a comment.  I read them every day.

Access Denied

This is probably one of the most common support requests that we see here.  There are a lot of causes for getting an “Access Denied” error when deploying VNCScan, running scripts, or performing the many other remote Windows management tasks.  Some of these may seem like a no-brainer to you while others may be unexpected.

 

Set your Administrative account in VNCScan.

Let’s start by making sure that you have supplied Administrative credentials to VNCScan for it to use when connecting to remote computers.  Even if you are currently logged into your computer as a Domain Admin, it’s still a good idea to tell VNCScan what username and password to use when running scripts because it needs to pass those credentials to commands that don’t necessarily run under the context of the currently logged in user.

If you would like to use your domain admin username/password, the best place to put this into VNCScan would be the main program preferences. 

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You can fine tune this by overriding this username and password in the group properties as well as the individual computer properties.

 

Multiple Connections Error 1219

This problem may be affecting your ability to log in even if you don’t see the actual error message.  You may simply get something that says “Access Denied” when in reality, it’s happening because you’ve already logged into the remote workstation with an account that doesn’t have administrative access. 

Here’s how to test that:

  • Open a Command Prompt window on your computer
  • Type:
        NET USE \ComputerNamec$ /user:administrativeaccount password
        Replace ComputerName with the name of the remote computer
        Replace administrativeaccount with your administrator username
        Replace password with your actual password
  • Hit Enter and make note of the result

If you get an Access Denied, then the username that you are using is not administrative on the remote system.   You’ll need to stop there and resolve that problem before moving forward.

If you get an error that reads “Multiple connections to a server or shared resource by the same user, using more than one user name, are not allowed. Disconnect all previous connections to the server or shared resource and try again”, you have already connected to a shared resource on that remote computer using a username other than the one that you are attempting to use with VNCScan.

You can see your list of connections by switching back to that Command Prompt window and simply typing NET USE then hitting Enter.  That will show you something like this:

 

U:>net use
New connections will not be remembered.

Status       Local     Remote                    Network

—————————————————————————–
OK           U:        \dell_200Steveb        Microsoft Windows Network
OK           W:        \dell_200Apps          Microsoft Windows Network
OK           X:        \dell_200Groups        Microsoft Windows Network
OK           Z:        \dell_200express       Microsoft Windows Network

If the above connections were made with my normal user account and I try to deploy VNC to \dell_200, I will likely get denied access even though I am supplying VNCScan a domain admin account.  This is simply a limitation of SMB connections in Windows.

Lucky for us, there is a work around for this problem.  As it turns out, Windows only keeps track of this login-to-workstation relationship on a per-computername basis.  This means that you can simply re-authenticate with the remote computer using the IP Address instead of the hostname and it will let you connect twice to the same computer with different credentials! 

We’ve placed a checkbox just for this in VNCScan.  It’s in the main program preferences right here:

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As with most of the settings in VNCScan, you can override this in the group properties as well as the individual computer properties.

Other tricks around this include assigning multiple DNS names to a computer on your DNS Server or simply using the /DELETE switch for NET USE to delete the preexisting connection.  NET USE /? will give full details on how to use this command.

Conclusion

Well, that’s it for this article.  In the next article, we will discuss firewall ports and other network related connectivity issues that may come into play.

I look forward to reading all of your comments and suggestions for this topic.