In my particular case I have setup router using WAN port attached to the modem and the client devices on LAN ports!
2. Add new interface myVPN using Network | Interfaces and change protocol to VPNC. Now you can setup VPN Server IP address, user name and password, group name and password. Important! In my case output interface is wan, because WAN port connected to outgoing modem!
and add myVPN interface to the lan firewall section of interface settings!
3. Switch now to the Network | Firewall and navigate to Custom Rules
You have to add forwarding rules for new myVPN interface
iptables -A forwarding_rule -o vpn-myVPN -j ACCEPT
iptables -A forwarding_rule -i vpn-myVPN -j ACCEPT
iptables -t nat -A postrouting_rule -o vpn-myVPN -j MASQUERADE
4. Add static routing to the subnetworks behind VPN connection as last step under Network | Static routes
Enjoy!
