If you are connecting to the VPN fine, but you cannot pass any traffic this is usually related to a local config import error.
The most common type of import error is the LZO compression does not get set properly.
This is easy to change:
Click on the applet -> Hover over the vpn connections option -> Choose configure vpn
Now click on the vpn connection you want to modify -> Click edit
Click on advanced
Now click on the “use LZO data compression” (should look like the screen shot)
Click OK -> Apply and you should now be able to reconnect and it will work. If you still have issues please send us the log files.