Fortinet Network Router FORTIOS V30 MR7 User Manual

U S E R G U I D E  
FortiOS v3.0 MR7  
SSL VPN User Guide  
 
Contents  
Contents  
Port-forwarding mode.................................................................................. 16  
Client requirements............................................................................... 17  
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Contents  
Configuring pass through for port-forwarding mode............................. 48  
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Contents  
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Introduction  
About FortiGate SSL VPN  
Introduction  
This section introduces you to FortiGate™ Secure Sockets Layer (SSL) VPN  
technology and provides supplementary information about Fortinet™ publications.  
The following topics are included in this section:  
About FortiGate SSL VPN  
FortiGate SSL VPN technology makes it safe to do business over the Internet. In  
addition to encrypting and securing information sent from a web browser to a web  
server, FortiGate SSL VPN can be used to encrypt most Internet-based traffic.  
With the FortiGate unit’s built-in SSL VPN capabilities, small home offices,  
medium-sized businesses, enterprises, and service providers can ensure the  
confidentiality and integrity of data transmitted over the Internet. The FortiGate  
unit provides enhanced authentication and restricted access to company network  
resources and services.  
The two modes of SSL VPN operation, supported in NAT/Route mode only, are:  
web-only mode, for thin remote clients equipped with a web browser only  
tunnel mode, for remote computers that run a variety of client and server  
applications  
When the FortiGate unit provides services in web-only mode, a secure web  
connection between the remote client and the FortiGate unit is established using  
the SSL VPN security in the FortiGate unit and the SSL security in the web  
browser. After the connection has been established, the FortiGate unit provides  
access to selected services and network resources through a web portal.  
Where users have complete administrative rights over their computers and use a  
variety of applications, tunnel mode allows remote clients to access the local  
internal network as if they were connected to the network directly. In tunnel mode,  
a secure SSL connection is established initially for the FortiGate unit to download  
SSL VPN client software (an ActiveX plugin) to the web browser. After the user  
installs the SSL VPN client software, they can initiate a VPN tunnel with the  
FortiGate unit whenever the SSL connection is open.  
When the SSL VPN feature is used, all client traffic is encrypted and sent to the  
SSL VPN. This includes both traffic intended for the private network and Internet  
traffic that is normally sent unencrypted. Split tunneling ensures that only the  
traffic for the private network is sent to the SSL VPN gateway. Internet traffic is  
sent through the usual unencrypted route. This conserves bandwith and alleviates  
bottlenecks. The split tunneling feature is not enabled by default.  
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About this document  
Introduction  
Whether to use web-only or tunnel mode depends on the number and type of  
applications installed on the remote computer. Access to any application not  
supported through web-only mode can be supported through tunnel mode. For  
more information about these modes of operation, see “Configuring a FortiGate  
About this document  
This document explains how to configure SSL VPN operation using the web-  
based manager and contains the following chapters:  
Configuring a FortiGate SSL VPN describes the two modes of operation,  
recommends a deployment topology, and provides an overview of the  
associated infrastructure dependencies. The high-level steps for configuring  
each mode of operation are also included with cross-references to underlying  
procedures. This chapter also details the basic administrative tasks needed to  
support the two modes of operation, and describes the additional step-by-step  
procedures needed to configure each mode.  
Working with the web portal introduces the web portal applications and  
explains how to work with them. The chapter also explains how to install the  
ActiveX plugin and initiate a VPN tunnel when tunnel mode is enabled.  
Document conventions  
The following document conventions are used in this guide:  
In the examples, private IP addresses are used for both private and public IP  
addresses.  
Notes and Cautions are used to provide important information:  
Note: Highlights useful additional information.  
Caution: Warns you about commands or procedures that could have unexpected or  
!
undesirable results including loss of data or damage to equipment.  
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Introduction  
FortiGate documentation  
Typographic conventions  
FortiGate documentation uses the following typographical conventions:  
Convention  
Example  
Keyboard input  
Code examples  
In the Name field, type admin.  
config sys global  
set ips-open enable  
end  
CLI command syntax  
config firewall policy  
edit id_integer  
set http_retry_count <retry_integer>  
set natip <address_ipv4mask>  
end  
Document names  
File content  
FortiGate SSL VPN User Guide  
<HTML><HEAD><TITLE>Firewall  
Authentication</TITLE></HEAD>  
<BODY><H4>You must authenticate to use this  
service.</H4>  
Menu commands  
Program output  
Variables  
Go to VPN > SSL > Config.  
Welcome!  
<group_name>  
FortiGate documentation  
The most up-to-date publications and previous releases of Fortinet product  
documentation are available from the Fortinet Technical Documentation web site  
The following FortiGate product documentation is available:  
FortiGate QuickStart Guide  
Provides basic information about connecting and installing a FortiGate unit.  
FortiGate Installation Guide  
Describes how to install a FortiGate unit. Includes a hardware reference,  
default configuration information, installation procedures, connection  
procedures, and basic configuration procedures. Choose the guide for your  
product model number.  
FortiGate Administration Guide  
Provides basic information about how to configure a FortiGate unit, including  
how to define FortiGate protection profiles and firewall policies; how to apply  
intrusion prevention, antivirus protection, web content filtering, and spam  
filtering; and how to configure a VPN.  
FortiGate online help  
Provides a context-sensitive and searchable version of the Administration  
Guide in HTML format. You can access online help from the web-based  
manager as you work.  
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Related documentation  
Introduction  
FortiGate CLI Reference  
Describes how to use the FortiGate CLI and contains a reference to all  
FortiGate CLI commands.  
Available exclusively from the Fortinet Knowledge Center, the FortiGate Log  
Message Reference describes the structure of FortiGate log messages and  
provides information about the log messages that are generated by FortiGate  
units.  
FortiGate High Availability User Guide  
Contains in-depth information about the FortiGate high availability feature and  
the FortiGate clustering protocol.  
FortiGate IPS User Guide  
Describes how to configure the FortiGate Intrusion Prevention System settings  
and how the FortiGate IPS deals with some common attacks.  
FortiGate IPSec VPN User Guide  
Provides step-by-step instructions for configuring IPSec VPNs using the web-  
based manager.  
FortiGate SSL VPN User Guide  
Compares FortiGate IPSec VPN and FortiGate SSL VPN technology, and  
describes how to configure web-only mode and tunnel-mode SSL VPN access  
for remote users through the web-based manager.  
FortiGate PPTP VPN User Guide  
Explains how to configure a PPTP VPN using the web-based manager.  
FortiGate Certificate Management User Guide  
Contains procedures for managing digital certificates including generating  
certificate requests, installing signed certificates, importing CA root certificates  
and certificate revocation lists, and backing up and restoring installed  
certificates and private keys.  
FortiGate VLANs and VDOMs User Guide  
Describes how to configure VLANs and VDOMS in both NAT/Route and  
Transparent mode. Includes detailed examples.  
Related documentation  
Additional information about Fortinet products is available from the following  
related documentation.  
FortiManager documentation  
FortiManager QuickStart Guide  
Explains how to install the FortiManager Console, set up the FortiManager  
Server, and configure basic settings.  
FortiManager System Administration Guide  
Describes how to use the FortiManager System to manage FortiGate devices.  
FortiManager System online help  
Provides a searchable version of the Administration Guide in HTML format.  
You can access online help from the FortiManager Console as you work.  
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Introduction  
Related documentation  
FortiClient documentation  
FortiClient Host Security User Guide  
Describes how to use FortiClient Host Security software to set up a VPN  
connection from your computer to remote networks, scan your computer for  
viruses, and restrict access to your computer and applications by setting up  
firewall policies.  
FortiClient Host Security online help  
Provides information and procedures for using and configuring the FortiClient  
software.  
FortiMail documentation  
FortiMail Administration Guide  
Describes how to install, configure, and manage a FortiMail unit in gateway  
mode and server mode, including how to configure the unit; create profiles and  
policies; configure antispam and antivirus filters; create user accounts; and set  
up logging and reporting.  
FortiMail online help  
Provides a searchable version of the Administration Guide in HTML format.  
You can access online help from the web-based manager as you work.  
FortiMail Web Mail Online Help  
Describes how to use the FortiMail web-based email client, including how to  
send and receive email; how to add, import, and export addresses; and how to  
configure message display preferences.  
FortiAnalyzer documentation  
FortiAnalyzer Administration Guide  
Describes how to install and configure a FortiAnalyzer unit to collect FortiGate  
and FortiMail log files. It also describes how to view FortiGate and FortiMail log  
files, generate and view log reports, and use the FortiAnalyzer unit as a NAS  
server.  
FortiAnalyzer online help  
Provides a searchable version of the Administration Guide in HTML format.  
You can access online help from the web-based manager as you work.  
Fortinet Tools and Documentation CD  
All Fortinet documentation is available from the Fortinet Tools and Documentation  
CD shipped with your Fortinet product. The documents on this CD are current at  
shipping time. For up-to-date versions of Fortinet documentation see the Fortinet  
Technical Documentation web site at http://docs.forticare.com.  
Fortinet Knowledge Center  
Additional Fortinet technical documentation is available from the Fortinet  
Knowledge Center. The knowledge center contains troubleshooting and how-to  
articles, FAQs, technical notes, and more. Visit the Fortinet Knowledge Center at  
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Customer service and technical support  
Introduction  
Comments on Fortinet technical documentation  
Please send information about any errors or omissions in this document, or any  
Fortinet technical documentation, to [email protected].  
Customer service and technical support  
Fortinet Technical Support provides services designed to make sure that your  
Fortinet systems install quickly, configure easily, and operate reliably in your  
network.  
Please visit the Fortinet Technical Support web site at http://support.fortinet.com  
to learn about the technical support services that Fortinet provides.  
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Configuring a FortiGate SSL VPN  
Comparison of SSL and IPSec VPN technology  
Configuring a FortiGate SSL VPN  
This section provides a comparison of SSL and IPSec VPN technology, in addition  
to an overview of the two modes of SSL VPN operation. The high-level steps for  
configuring each mode are also included with cross-references to underlying  
procedures.  
The following topics are included in this section:  
Comparison of SSL and IPSec VPN technology  
The FortiGate unit supports both SSL and IPSec VPN technologies. Each  
combines encryption and VPN gateway functions to create private communication  
channels over the Internet, which helps to defray physical network costs. Both  
enable you to define and deploy network access and firewall policies using a  
single management tool. In addition, both support a simple client/user  
authentication process (including optional X.509 security certificates). You have  
the freedom to use both technologies; however, one may be better suited to the  
requirements of your situation.  
In general, IPSec VPNs are a good choice for site-to-site connections where  
appliance-based firewalls are used to provide network protection, and company  
sanctioned client computers are issued to users. SSL VPNs are a good choice for  
roaming users who depend on a wide variety of thin-client computers to access  
enterprise applications and/or company resources from a remote location.  
SSL and IPSec VPN tunnels may operate simultaneously on the same FortiGate  
unit.  
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Comparison of SSL and IPSec VPN technology  
Configuring a FortiGate SSL VPN  
Legacy versus web-enabled applications  
IPSec is well suited to network-based legacy applications that are not web-based.  
As a layer 3 technology, IPSec creates a secure tunnel between two host devices.  
IP packets are encapsulated by the VPN client and server software running on the  
hosts.  
SSL is typically used for secure web transactions in order to take advantage of  
web-enabled IP applications. After a secure HTTP link has been established  
between the web browser and web server, application data is transmitted directly  
between selected client and server applications through the tunnel.  
Authentication differences  
IPSec is a well-established technology with robust features that support many  
legacy products such as smart cards and biometrics.  
SSL supports sign-on to a web portal front-end, from which a number of different  
enterprise applications may be accessed. The Fortinet implementation enables  
you to assign a specific port for the web portal and to customize the login page if  
desired.  
Connectivity considerations  
IPSec supports multiple connections to the same VPN tunnel—a number of  
remote VPN devices effectively become part of the same network.  
SSL forms a connection between two end points such as a remote client and an  
enterprise network. Transactions involving three (or more) parties are not  
supported because traffic passes between client and server applications only.  
Relative ease of use  
Although managing IPSec VPNs has become easier, configuring SSL VPNs is  
simple in comparison. IPSec protocols may be blocked or restricted by some  
companies, hotels, and other public places, whereas the SSL protocol is usually  
unrestricted.  
Client software requirements  
Dedicated IPSec VPN software must be installed on all IPSec VPN peers and  
clients and the software has to be configured with compatible settings.  
To access server-side applications with SSL VPN, the remote user must have a  
web browser (Internet Explorer, Netscape, or Mozilla/Firefox), and if Telnet//RDP  
are used, Sun Java runtime environment. Tunnel-mode client computers must  
also have ActiveX (IE) or Java Platform (Mozilla/Firefox) enabled.  
Access control  
IPSec VPNs provide secure network access only. Access to the network  
resources on a corporate IPSec VPN can be enabled for specific IPSec peers  
and/or clients. The amount of security that can be applied to users is limited.  
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Configuring a FortiGate SSL VPN  
SSL VPN modes of operation  
SSL VPNs provide secure access to certain applications. Web-only mode  
provides remote users with access to server applications from any thin client  
computer equipped with a web browser. Tunnel-mode provides remote users with  
the ability to connect to the internal network from laptop computers as well as  
airport kiosks, Internet cafes, and hotels. Access to SSL VPN applications is  
controlled through user groups.  
Session failover support  
In a FortiGate high availability (HA) cluster with session pickup enabled, session  
failover is supported for IPSec VPN tunnels. After an HA failover, IPSec VPN  
tunnel sessions will continue with no loss of data.  
Session failover is not supported by SSL VPN tunnels, however cookie failover is  
supported for communication between the SSL VPN client and the FortiGate unit.  
This means that after a failover, the SSL VPN client can re-establish the SSL VPN  
session without having to authenticate again. However, all sessions inside the  
SSL VPN tunnel with resources behind the FortiGate unit will stop, and will  
therefore have to be restarted.  
SSL VPN modes of operation  
When a remote client connects to the FortiGate unit, the FortiGate unit  
authenticates the user based on user name, password, and authentication  
domain. A successful login determines the access rights of remote users  
according to user group. The user group settings specify whether the connection  
will operate in web-only mode (see “Web-only mode” on page 15) or tunnel mode  
You can enable a client integrity checker to scan the remote client. The integrity  
checker probes the remote client computer to verify that it is “safe” before access  
is granted. Security attributes recorded on the client computer (for example, in the  
Windows registry, in specific files, or held in memory due to running processes)  
are examined and uploaded to the FortiGate unit.  
You can enable a cache cleaner to remove any sensitive data that would  
otherwise remain on the remote computer after the session ends. For example, all  
cache entries, browser history, cookies, encrypted information related to user  
authentication, and any temporary data generated during the session are  
removed from the remote computer. If the client’s browser cannot install and run  
the cache cleaner, the user is not allowed to access the SSL-VPN portal.  
Web-only mode  
Web-only mode provides remote users with a fast and efficient way to access  
server applications from any thin client computer equipped with a web browser.  
Web-only mode offers true clientless network access using any web browser that  
has built-in SSL encryption and the Sun Java runtime environment.  
Support for SSL VPN web-only mode is built into the FortiOS operating system.  
The feature comprises an SSL daemon running on the FortiGate unit, and a web  
portal, which provides users with access to network services and resources  
including HTTP/HTTPS, telnet, FTP, SMB/CIFS, VNC, RDP and SSH.  
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