I´m trying to connect vpn client pptp to remote server and it doesn´t work on my actual place. Here is fritzbox 7390. Vpn works because i tried before with the same laptop in another place. Thanks.
The problem was not on fritz!box router but in internet provider(P&T luxembourg). The router has not public ip. Instead of this, it has another LAN ip, so all the building share tha same public ip. So there is double NAT and this affects PPTP vpn protocol. I change to openvpn that can pass through double nat networks.