This FortiOS Handbook chapter contains the following sections:
IPsec VPN concepts explains the basic concepts that you need to understand about virtual private networks (VPNs).
IPsec VPN overview provides a brief overview of IPsec technology and includes general information about how to configure IPsec VPNs using this guide.
IPsec VPN in the web-based manager describes the IPsec VPN menu of the web-based manager interface.
Gateway-to-gateway configurations explains how to set up a basic gateway-to-gateway (site-to-site) IPsec VPN. In a gateway-to-gateway configuration, two FortiGate units create a VPN tunnel between two separate private networks.
Hub-and-spoke configurations describes how to set up hub-and-spoke IPsec VPNs. In a hub-and-spoke configuration, connections to a number of remote peers and/or clients radiate from a single, central FortiGate hub.
Dynamic DNS configuration describes how to configure a site-to-site VPN, in which one FortiGate unit has a static IP address and the other FortiGate unit has a dynamic IP address and a domain name.
FortiClient dialup-client configurations guides you through configuring a FortiClient dialup-client IPsec VPN. In a FortiClient dialup-client configuration, the FortiGate unit acts as a dialup server and VPN client functionality is provided by the FortiClient Endpoint Security application installed on a remote host.
FortiGate dialup-client configurations explains how to set up a FortiGate dialup-client IPsec VPN. In a FortiGate dialup-client configuration, a FortiGate unit with a static IP address acts as a dialup server and a FortiGate unit with a dynamic IP address initiates a VPN tunnel with the FortiGate dialup server.
Supporting IKE Mode config clients explains how to set up a FortiGate unit as either an IKE Mode Config server or client. IKE Mode Config is an alternative to DHCP over IPsec.
Internet-browsing configuration explains how to support secure web browsing performed by dialup VPN clients, and hosts behind a remote VPN peer. Remote users can access the private network behind the local FortiGate unit and browse the Internet securely. All traffic generated remotely is subject to the security policy that controls traffic on the private network behind the local FortiGate unit.
Redundant VPN configurations discusses the options for supporting redundant and partially redundant tunnels in an IPsec VPN configuration. A FortiGate unit can be configured to support redundant tunnels to the same remote peer if the FortiGate unit has more than one interface to the Internet.
Transparent mode VPNs describes two FortiGate units that create a VPN tunnel between two separate private networks transparently. In transparent mode, all FortiGate unit interfaces except the management interface are invisible at the network layer.
IPv6 IPsec VPNs describes FortiGate unit VPN capabilities for networks based on IPv6 addressing. This includes IPv4-over-IPv6 and IPv6-over-IPv4 tunnelling configurations. IPv6 IPsec VPNs are available in FortiOS 3.0 MR5 and later.
L2TP and IPsec (Microsoft VPN) explains how to support Microsoft Windows native VPN clients.
GRE over IPsec (Cisco VPN) explains how to interoperate with Cisco VPNs that use Generic Routing Encapsulation (GRE) protocol with IPsec.
Protecting OSPF with IPsec provides an example of protecting OSPF links with IPsec.
Redundant OSPF routing over IPsec provides an example of redundant secure communication between two remote networks using an OSPF VPN connection.
OSPF over dynamic IPsec provides an example of how to create a dynamic IPsec VPN tunnel that allows OSPF.
BGP over dynamic IPsec provides an example of how to create a dynamic IPsec VPN tunnel that allows BGP.
Phase 1 parameters provides detailed step-by-step procedures for configuring a FortiGate unit to accept a connection from a remote peer or dialup client. The basic Phase 1 parameters identify the remote peer or clients and support authentication through preshared keys or digital certificates. You can increase VPN connection security further using methods such as extended authentication (XAuth).
Phase 2 parameters provides detailed step-by-step procedures for configuring an IPsec VPN tunnel. During Phase 2, the specific IPsec security associations needed to implement security services are selected and a tunnel is established.
Defining VPN security policies explains how to specify the source and destination IP addresses of traffic transmitted through an IPsec VPN tunnel, and how to define a security encryption policy. Security policies control all IP traffic passing between a source address and a destination address.