How To Connect to a Computer on a Private LAN Using a SonicWALL SSL VPN Client


This article is designed to help ASCS IT Consulting & Management (ASCS) customers understand how to remotely access a Windows 10 computer located on their private LAN ─ using a SonicWALL SSL VPN connection. The article assumes that ASCS has installed and configured the SonicWALL appliance as well as any domain names and IP addresses needed.

Remotely accessing a computer located on a private LAN using the SonicWALL SSL VPN client (NetExtender) and the Windows Remote Desktop software (RDP) is possible if the following requirements are met:

  • The SonicWALL appliance has been set up and the SSL VPN services have been configured.
  • The remote user has:
    • A SonicWALL SSL VPN user account.
    • A Windows user account to access the computer on the private LAN.
    • The domain name for the SonicWALL appliance.
  • The remote computer has the NetExtender software installed.
  • The private LAN computer is configured to accept RDP connections.
  • The SonicWALL user account and private LAN computer user account may have diffrent credentials. That is, the username and password for the VPN client may be different from the Windows username and password. Make sure you have the correct credentials. ASCS will supply your credentials.
  • Both the remote computer and the private LAN computer should have the latest Microsoft updates installed. It may not be possible to make an RDP connection if the updates are not installed.

Once connected to the private LAN computer, through the VPN, the remote user can control the private LAN computer pretty much as if he or she were sitting in front of it in the private office. Accessing the private LAN computer in this way helps keeps data on the private network. This is because only keyboard, mouse and video traffic will be passed between the remote computer and the private LAN computer. Of course, this is not the case if files are moved or copied to the remote computer.

Installing NetExtender

ASCS will download and supply the NetExtender software to its customers. We will make sure the remote computer has the latest version of NetExtender installed and working properly.

Connecting to the Private Computer

Connecting to the private computer is accomplished in two steps. These steps must be completed in the order listed.

The steps are as follows:

  1. Establish a VPN connection to the SonicWALL appliance.
  2. Establish a Windows RDP connection to the private LAN computer.
  • You cannot create an RDP Connection to the private LAN computer until you have successfully established a VPN connection using NetExtender.
  • Idle VPN connections may timeout after a predefined period. This will depend on how the SonicWALL is configured.

Establishing the VPN Connection to the SonicWALL Appliance

Step 1:

Locate and launch the NetExtender software. Typically, ASCS will place a NetExtender shortcut/icon on your desktop when we install the software. Simply click this icon to start NetExtender.

Step 2:
  • Enter the server address (domain-name:4433) in the Server field. The server’s domain name will be provided by ASCS.
  • Enter your VPN username and password. Note that both the username and password are case sensitive.
  • Enter “LocalDomain” in the Domain field.
  • Click Connect.
Step 3:

Click on either the Accept or the Always Trust button when presented with the Security Alert dialog box shown below.


Step 4:

Confirm you are presented with a confirmation dialog box as shown below. Notice the username and time connected are shown on the right side of the gray bar.

Now proceed to the next section ─ Establishing a Windows RDP to the private LAN computer.

Establishing a Windows RDP Connection to the Private LAN Computer

Once you have established a VPN connection to the private network, use the following steps to connect to the private LAN computer.

Step 1:

Locate and click the RDP icon. This icon can be found by typing “Remote” into the Windows 10 Search Bar. Typically, ASCS will save a shortcut to your desktop so you don’t have to search for it.

Step 2:
  • Enter the private LAN computer’s IP address (or domain name) into the Computer field. The address or domain name will be provided by ASCS. Note that the IP shown in the screenshot below is just a sample.
  • Click Connect.
Step 3:

If presented with a security dialog box like (or similar to) the one shown below, go ahead and click the Connect button. You may also place a tick mark in the “Don’t ask me again for connections to this computer” check box.

Step 4:

Enter your Windows credentials. This is the username and password for the private LAN computer ─ do not confuse them with your NetExtender username and password.

Step 5:

If presented with a security dialog box like (or similar to) the one shown below, click on the Yes button. You may also place a tick mark in the “Don’t ask me again for connections to this computer” check box.


Step 6:

Confirm you are presented with private LAN computer’s desktop. This will be the desktop of the private LAN computer. It will appear on your screen like an application window. You will know it is the private LAN computer’s desktop by the presence of a control bar at the top of the screen (as shown in the image below).

  • The control bar on the private LAN computer may hide itself after a few seconds. If this happens, move your mouse pointer to the position of the control bar and it should reappear. You can force the control bar to stay in view by clicking on the thumbtack icon located on the left side of the control bar.

Ending Your Remote Session

There are two ways to end your remote session:

  1. Click the “X” icon located on the top right corner of the control bar — in the RDP session window (see the screenshot above).
  2. Click on the Windows menu located in the bottom left corner of the RDP session window and then click Disconnect from the pop up menu (see the image below).
  • Be sure not to confuse your main window (of your local machine) with the RDP session window. The actions required to disconnect the RDP session must be executed in the RDP session window.
  • When finished working with the private LAN computer, be careful to disconnect and not shutdown the private LAN computer as shutting down the private computer will prevent you from remotely connecting again later.
  • It is strongly recommended that you close all your applications (Word, Excel, Sage 50, etc.) before ending your remote session. Leaving applications open when your computer is not in use could lead to corrupt data or other software problems.