Settings for Main office
1. Setup interfaces, System->Interfaces:
WAN IP: 194.0.2.20
LAN IP: 192.168.1.1, Subnet mask: 255.255.255.0
2. Setup IPSec tunnel, Firewall->VPN:
Under IPSec tunnels click add new
Name the tunnel ToBranchOffice
Local net: 192.168.1.0/24
PSK: 1234567890 (Note! You should use a key that is hard to guess)
Retype PSK: 1234567890
Select Tunnel type: LAN-to-LAN tunnel
Remote Net: 192.168.4.0/24
Remote Gateway: 194.0.2.10
Enable "Automatically add a route for the remote network"
Click Apply