Mikrotik - forwarding 3g modem via vpn?

Question

VPN

1. there is a 3G modem
2. there is a microtik with Internet access via cable
3. mikrotik is behind NAT and does not have an external
ip to the Internet through your 3G modem (through a raised tunnel).

Answer 1

Steamy question, what for? If on the server where we are knocking on the van, and so already there is Internet
routing at school taught ????
1. Set up a connection from Mikrotik to VPN (L2TP, PPTP) in the corresponding tab
2. On the VPN Server, we say that all traffic on port, say 80, is routed through the Mikrotik address (on the VPN server, register the route to the Mikrotik address through the tunnel)