FireBrick IPsec (Road Warrior Howto)
FireBrick Road Warrior IPsec
The FireBrick manual goes into some detail on configuring IPsec. This page contains specific examples for a simple scenario where you have one or more clients devices - iPhones iPads, Android phones/tablets or Windows machines, and a FireBrick in your home or office, and you would like to VPN (using IPsec) to the FireBrick and have an IP address on your LAN.
In this example we are assuming you can allocate some IP addresses on you LAN. You do this by picking a range of addresses and setting up a roaming-pool (see below). You need to ensure the IP range does not clash with devices on the LAN and is not in the DHCP ranges that could allocate to the LAN. You also need to set proxy-arp on the LAN interface settings to allow communications to other devices on your LAN. Alternatively you could set private IP addresses in the pool and set the nat setting. You should probably also consider firewalling rules for traffic to/from IPsec connections.