Hi, my Home-Network contains a Linksys WRT54GL router with the Tomato 1.28 firmware. Now i'm trying to connect a Synology NAS (with a PPTP VPN-Server on it) in this network, but from an external network. So i have tried the following router settings:  In Tomato webadmin i created a 'Port Forwarding' (Proto: tcp, Ext Ports: 1723, Int Address: 192.168.1.10 ... the NAS/VPN-Server) and 'NAT Helpers > GRE/PPTP' was checked  Under 'Scripts > Firewall' i made those additional rules: iptables -t nat -I PREROUTING -p tcp --dport 1723 -j DNAT --to 192.168.1.10 iptables -I FORWARD -p tcp -d 192.168.1.10 --dport 1723 -j ACCEPT iptables -t nat -I PREROUTING -p 47 -j DNAT --to 192.168.1.10 iptables -I FORWARD -p 47 -d 192.168.1.10 -j ACCEPT At no time i was able to establish an VNP connection from external networks to my home-network VPN-Server. The VPN-Client log contains: I do not understand why IP GRE is not forwarded correctly. TCP Forwards (e.g. port 8080) are working perfect. Does anyone have any idea how I could solve this problem? Thanks!