I'm trying to set up a VPN connection on my RPi, but always times out. I have a DDNS setup and the public IP address is updated using ddclient. I have a network machine connected to eth0 and a 3g dongle (eth1) connected via a powered usb hub, and have tested the settings with a normal router with port forwarding and all worked.
Unfortunately I need to put the Pi in a location where normal Internet connections are not available (hence the 3g dongle). The Pi seems to ignore or is unaware of any incoming connections when I try to connect with my pc. It may just be an iptables command that I have not yet worked out or some kind of routing issue. Can anyone help?