FAQ : Connectivity (Tunnels and Subnets) : My tunnel doesn't work
My tunnel doesn't work
Then you should do some testing:
Then you should try:
If those work you are done and a default route should take care of the rest.
If it doesn't you should:
Have fun debugging...
When the problem persists and you can't figure it out, then read the "Reporting Problems" section on the Contact page which contains an even longer list of things you can test out to figure out at least where the problem occurs.