Chapter 11 IPsec VPN for FortiOS 5.0 : Hub-and-spoke configurations : Dynamic spokes configuration example : Configure the spokes
  
Configure the spokes
In this example, all spokes have nearly identical configuration, requiring the following:
phase 1 authentication parameters to initiate a connection with the hub
phase 2 tunnel creation parameters to establish a VPN tunnel with the hub
a source address that represents the network behind the spoke. This is the only part of the configuration that is different for each spoke.
a destination address that represents the aggregate protected network
a security policy to enable communications between the spoke and the aggregate protected network