LAN-to-LAN VPN using IPsec
Settings for Branch office
1.Setup interfaces,
LAN IP: 192.168.4.1, Subnet mask: 255.255.255.0
2.Setup IPsec tunnel,
Under IPsec tunnels click Add new
Name the tunnel ToMainOffice
Local net: 192.168.4.0/24
PSK: 1234567890 (Note! You should use a key that is hard to guess)