SSL VPN

This chapter provides information on how to configure the SSL VPN features on the Dell SonicWALL security appliance. Dell SonicWALL’s SSL VPN features provide secure remote access to the network using the NetExtender client.

NetExtender is an SSL VPN client for Windows, Mac, or Linux users that is downloaded transparently and that allows you to run any application securely on the company’s network. It uses Point-to-Point Protocol (PPP). NetExtender allows remote clients seamless access to resources on your local network. Users can access NetExtender two ways:

• Logging in to the Virtual Office web portal provided by the Dell SonicWALL security appliance and clicking on the NetExtender button.

• Launching the standalone NetExtender client.

The NetExtender standalone client is installed the first time you launch NetExtender. Thereafter, it can be accessed directly from the Start menu on Windows systems, from the Application folder or dock on MacOS systems, or by the path name or from the shortcut bar on Linux systems.

This chapter contains the following sections:

SSL VPN NetExtender Overview

Configuring Users for SSL VPN Access

SSL VPN > Status

SSL VPN > Server Settings

SSL VPN > Client Settings

SSL VPN > Portal Settings

SSL VPN > Virtual Office

Accessing the Dell SonicWALL SSL VPN Portal

Using NetExtender

Configuring SSL VPN Bookmarks

Using SSL VPN Bookmarks

 

SSL VPN NetExtender Overview

This section provides an introduction to the SonicOS Enhanced SSL VPN NetExtender feature. This section contains the following subsections:

What is SSL VPN NetExtender?

Benefits

NetExtender Concepts

What is SSL VPN NetExtender?

Dell SonicWALL’s SSL VPN NetExtender feature is a transparent software application for Windows, Mac, and Linux users that enables remote users to securely connect to the remote network. With NetExtender, remote users can securely run any application on the remote network. Users can upload and download files, mount network drives, and access resources as if they were on the local network. The NetExtender connection uses a Point-to-Point Protocol (PPP) connection.

Benefits

NetExtender provides remote users with full access to your protected internal network. The experience is virtually identical to that of using a traditional IPSec VPN client, but NetExtender does not require any manual client installation. Instead, the NetExtender Windows client is automatically installed on a remote user’s PC by an ActiveX control when using the Internet Explorer browser, or with the XPCOM plugin when using Firefox. On MacOS systems, supported browsers use Java controls to automatically install NetExtender from the Virtual Office portal. Linux systems can also install and use the NetExtender client.

After installation, NetExtender automatically launches and connects a virtual adapter for secure SSL-VPN point-to-point access to permitted hosts and subnets on the internal network.

 

NetExtender Concepts

The following sections describe advanced NetExtender concepts:

Stand-Alone Client

Client Routes

Tunnel All Mode

Connection Scripts

Proxy Configuration

Dell SonicWALL Mobile Connect

Stand-Alone Client

NetExtender is a browser-installed lightweight application that provides comprehensive remote access without requiring users to manually download and install the application. The first time a user launches NetExtender, the NetExtender stand-alone client is automatically installed on the user’s PC or Mac. The installer creates a profile based on the user’s login information. The installer window then closes and automatically launches NetExtender. If the user has a legacy version of NetExtender installed, the installer will first uninstall the old NetExtender and install the new version.

Once the NetExtender stand-alone client has been installed, Windows users can launch NetExtender from their PC’s Start > Programs menu and configure NetExtender to launch when Windows boots. Mac users can launch NetExtender from their system Applications folder, or drag the icon to the dock for quick access. On Linux systems, the installer creates a desktop shortcut in /usr/share/NetExtender. This can be dragged to the shortcut bar in environments like Gnome and KDE.

Client Routes

NetExtender client routes are used to allow and deny access for SSL VPN users to various network resources. Address objects are used to easily and dynamically configure access to network resources.

Tunnel All Mode

Tunnel All mode routes all traffic to and from the remote user over the SSL VPN NetExtender tunnel—including traffic destined for the remote user’s local network. This is accomplished by adding the following routes to the remote client’s route table:

IP Address

Subnet mask

0.0.0.0

0.0.0.0

0.0.0.0

128.0.0.0

128.0.0.0

128.0.0.0

NetExtender also adds routes for the local networks of all connected Network Connections. These routes are configured with higher metrics than any existing routes to force traffic destined for the local network over the SSL VPN tunnel instead. For example, if a remote user is has the IP address 10.0.67.64 on the 10.0.*.* network, the route 10.0.0.0/255.255.0.0 is added to route traffic through the SSL VPN tunnel.

Tunnel All mode is configured on the SSL VPN > Client Routes page.

Connection Scripts

Dell SonicWALL SSL VPN provides users with the ability to run batch file scripts when NetExtender connects and disconnects. The scripts can be used to map or disconnect network drives and printers, launch applications, or open files or Web sites. NetExtender Connection Scripts can support any valid batch file commands.

Proxy Configuration

Dell SonicWALL SSL VPN supports NetExtender sessions using proxy configurations. Currently, only HTTPS proxy is supported. When launching NetExtender from the Web portal, if your browser is already configured for proxy access, NetExtender automatically inherits the proxy settings. The proxy settings can also be manually configured in the NetExtender client preferences. NetExtender can automatically detect proxy settings for proxy servers that support the Web Proxy Auto Discovery (WPAD) Protocol.

NetExtender provides three options for configuring proxy settings:

Automatically detect settings - To use this setting, the proxy server must support Web Proxy Auto Discovery Protocol (WPAD)), which can push the proxy settings script to the client automatically.

Use automatic configuration script - If you know the location of the proxy settings script, you can select this option and provide the URL of the script.

Use proxy server - You can use this option to specify the IP address and port of the proxy server. Optionally, you can enter an IP address or domain in the BypassProxy field to allow direct connections to those addresses and bypass the proxy server. If required, you can enter a user name and password for the proxy server. If the proxy server requires a username and password, but you do not specify them, a NetExtender pop-up window will prompt you to enter them when you first connect.

When NetExtender connects using proxy settings, it establishes an HTTPS connection to the proxy server instead of connecting to the Dell SonicWALL security appliance. server directly. The proxy server then forwards traffic to the SSL VPN server. All traffic is encrypted by SSL with the certificate negotiated by NetExtender, of which the proxy server has no knowledge. The connecting process is identical for proxy and non-proxy users.

Dell SonicWALL Mobile Connect

Dell SonicWALL Mobile Connect is an app for iPhone, iPad, and iPod Touch that enables secure, mobile connections to private networks protected by Dell SonicWALL security appliances. The Dell SonicWALL Mobile Connect app for iPhone and iPad provides secure, mobile access to sensitive network resources using the iPhone and iPad. Dell SonicWALL Mobile Connect establishes a Secure Socket Layer Virtual Private Network (SSL VPN) connection to private networks that are protected by Dell SonicWALL security appliances. All traffic to and from the private network is securely transmitted over the SSL VPN tunnel.

The process for using Dell SonicWALL Mobile Connect is as follows:

1. Install Dell SonicWALL Mobile Connect from the App Store.

2. Enter connection information (server name, username, password, etc.).

3. Initiate a connection to the network.

4. Dell SonicWALL Mobile Connect establishes a SSL VPN tunnel to the Dell SonicWALL security appliance.

5. You can now access resources on the private network. All traffic to and from the private network is securely transmitted over thtrouble shooting reporte SSL VPN tunnel.

From the administrator’s perspective, Dell SonicWALL Mobile Connect functions virtually the same as NetExtender. Two administrator configurations are required

Configure Users for NetExtender – In order for a user to be able to connect with Dell SonicWALL Mobile Connect, their user account must be assigned to the SSLVPN Services group. See Configuring Users for SSL VPN Access for details.

Configuring Users for SSL VPN Access

In order for users to be able to access SSL VPN services, they must be assigned to the SSLVPN Services group. Users who attempt to login through the Virtual Office who do not belong to the SSLVPN Services group will be denied access.

The maximum number of SSL VPN concurrent users for each Dell SonicWALL network security appliance model supported in Release 5.9 is shown in the table below:

Dell SonicWALL Hardware Model

Maximum Concurrent SSL VPN Users

NSA E8510

1500

NSA E8500

1500

NSA E7500

1000

NSA E6500

750

NSA E5500

500

NSA 5000

350

NSA 4500

350

NSA 3500

250

NSA 2400 / 2400MX

125

NSA 250M / 250MW

50

NSA 240

50

NSA 220 / 220W

50

TZ 215 / 215W

25

TZ 210 / 210W

25

TZ 205 / 205W

15

TZ 200 / 200W

10

TZ 105 / 105W

10

TZ 100 / 100W

5

The following sections describe how to configure user accounts for SSL VPN access:

Configuring SSL VPN Access for Local Users

Configuring SSL VPN Access for RADIUS Users

Configuring SSL VPN Access for LDAP Users

Configuring SSL VPN Access for Local Users

To configure users in the local user database for SSL VPN access, you must add the users to the SSLVPN Services user group. To do so, perform the following steps:

1. Navigate to the Users > Local Users page.

2. Click on the configure icon icon_edit.jpg for the user you want to edit, or click the Add User button to create a new user. The Edit User window is launched.

3. Click on the Groups tab.

4. In the User Groups column, click on SSLVPN Services and click the right arrow to move it to the Member Of column.

5. Click on the VPN Access tab. The VPN Access tab configures which network resources VPN users (either GVC, NetExtender, or Virtual Office bookmarks) can access. Select one or more network address objects or groups from the Networks list and click the right arrow button (->) to move them to the Access List column. To remove the user’s access to a network address objects or groups, select the network from the Access List, and click the left arrow button (<-).

Note The VPN access tab affects the ability of remote clients using GVC, NetExtender, and SSL VPN Virtual Office bookmarks to access network resources. To allow GVC, NetExtender, or Virtual Office users to access a network resource, the network address objects or groups must be added to the “allow” list on the VPN Access tab.

6. Click OK.

Note The feature, One-Time Password, is a two-factor authentication scheme utilizing system-generated, random passwords, in addition to standard user name and password credentials, for users attempting to login through SSL VPN connections.

Configuring SSL VPN Access for RADIUS Users

To configure RADIUS users for SSL VPN access, you must add the users to the SSLVPN Services user group. To do so, perform the following steps:

1. Navigate to the Users > Settings page.

2. In the Authentication Method for login pulldown menu, select RADIUS or RADIUS + Local Users.

3. Click the Configure button for Authentication Method for login. The RADIUS Configuration window displays.

4. Click on the RADIUS Users tab.

5. In the Default user group to which all RADIUS users belong pulldown menu, select SSLVPN Services.

Note The VPN Access tab in the Edit User window is also another granular control on access for both Virtual Office Bookmarks and for NetExtender access.

6. Click OK.

Configuring SSL VPN Access for LDAP Users

To configure LDAP users for SSL VPN access, you must add the LDAP user groups to the SSLVPN Services user group. To do so, perform the following steps:

1. Navigate to the Users > Settings page.

2. Set the Authentication method for login to either LDAP or LDAP + Local Users.

3. Click the Configure button to launch the LDAP Configuration window.

4. Click on the LDAP Users tab.

5. In the Default LDAP User Group pulldown menu, select SSLVPN Services.

Note The VPN Access tab n the Edit User window is also another granular control on access for both Virtual Office Bookmarks and for NetExtender access.

6. Click OK.