Chapter 11 IPsec VPN for FortiOS 5.0 : IPsec VPN Overview : Planning your VPN : Network topologies
  
Network topologies
The topology of your network will determine how remote peers and clients connect to the VPN and how VPN traffic is routed. You can read about various network topologies and find the high-level procedures needed to configure IPsec VPNs in one of these sections.
Table 72: VPN network topologies and brief descriptions
Topology
Description
Standard one-to-one VPN between two FortiGate units. See “Gateway-to-gateway configurations”.
One central FortiGate unit has multiple VPNs to other remote FortiGate units. See “Hub-and-spoke configurations”.
One end of the VPN tunnel has a changing IP address and the other end must go to a dynamic DNS server for the current IP address before establishing a tunnel. See “Dynamic DNS configuration”.
Typically remote FortiClient dialup-clients use dynamic IP addresses through NAT devices. The FortiGate unit acts as a dialup server allowing dialup VPN connections from multiple sources. See “FortiClient dialup-client configurations”.
Similar to FortiClient dialup-client configurations but with more gateway-to-gateway settings such as unique user authentication for multiple users on a single VPN tunnel. See “FortiGate dialup-client configurations”.
Secure web browsing performed by dialup VPN clients, and/or hosts behind a remote VPN peer. See “Internet-browsing configuration”.
Options for supporting redundant and partially redundant IPsec VPNs, using route-based approaches. See “Redundant VPN configurations”.
In transparent mode, the FortiGate acts as a bridge with all incoming traffic being broadcast back out on all other interfaces. Routing and NAT must be performed on external routers. See “Transparent mode VPNs”.
Manually define cryptographic keys to establish an IPsec VPN, either policy-based or route-based. See “Manual-key configurations”.
Configure VPN for Microsoft Windows dialup clients using the built in L2TP software. Users do not have to install any See “L2TP and IPsec (Microsoft VPN)”.
These sections contain high-level configuration guidelines with cross-references to detailed configuration procedures. If you need more detail to complete a step, select the cross-reference in the step to drill-down to more detail. Return to the original procedure to complete the procedure. For a general overview of how to configure a VPN, see “General preparation steps” below.