1- Click the apple logo, then select System -> Preferences
2- Click on the Network icon
3- If you see a locked padlock in the bottom left, click on it and enter your password.
4- Click on the PLUS (+) icon just above the padlock
5- Select “VPN” From the interface drop down.
6- Chose “L2TP over IPSec ” From the VPN Type drop down
7- In Service Name, Enter 51ChinaVPN, and click “Create”
8- Enter the Server Address : 51vpn.xicp.cn, and your username which was emailed to you. Also check the box that says “Show VPN status in menu bar”
9- Click on the “Authentication Settings” button, and enter your password that was sent to you, and the shared secret: 51chinavpn
10-Click the “Advanced”
11- Check the box "Send all traffic Over VPN Connection" and click OK
12-Almost done. Click the “Apply” button to save the changes.
13- in the top right of your screen, click the token icon that looks like this. From that, a menu will drop down. Click on the “Connect” link to connect to 51ChinaVPN. This will initiate the VPN connection.
14- If all is well, after a few seconds you will be connected, and a timer will start showing you how long you’ve been connected