Finally I get the usbnetwork working - Thanks God!
I have search through the Internet and many people has problems of SSH to Kindle after installed the usbnetwork hack, most of them report getting an IP address of 192.168.15.1 instead of 192.168.15.201, that is because the MS Windows use a stupid "automatic obtain IP" by default and randomly assign an IP address!
And things do not get better as most of the guys making the hack are using Linux instead of Windows. Hence they use the following line in Linux:
#ifconfig usb0 192.168.15.201
will not work in Windows envirnoment!
People need to understand for the connection to work between the PC and Kindle, you need to have the correct IP address at both end: The PC side is 192.168.15.201 while the Kindle side is 192.168.15.244
To help people doing the right things in Windows environment, I have put up the following step by step intructions with dump screens (for Windows 7):
1. Following the hack instructions to install usbnetwork into your kindle.
2. Unplug Kindle and plug Kindle again, type ;un in the search field (with return key press) on your Kindle to enable the hack.
3. Unplug Kindle and plug Kindle again. Your computer will detect a new device and auto install the driver for it.
4. Go to the Device Manager and check that you have a new device called "USB Ethernet/RNDIS Gadget" under the Network adapters.
5. There is a Property called "Network address" in the Advanced tab if you click the properties button of that device -
DO NOT enter anything as the IP address cannot fit to it anyway (a bug in the driver?).
6. Go to the Network Center instead and click the correct Connection.
7. Click the Properties button of the Local Area Connection Status that has pop up.
8. Use the mouse to select "Internet Protocol Version 4 (TCP/IPv4)" and then click the Properties button.
9. Now this is the real thing - Select the "Use the following IP address" option.
10. Type in "192.168.15.201" without quote carefully on the "IP address".
11. Click OK and then another OK and then Close button and you are done!
You can use the dos command "ipconfig" to check if the IP address is correct or not.
Now you can use Putty or WinSCP (which I prefer) to talk to Kindle with the following settings -
IP address of other end: 192.168.15.244
username: root
password: mario
Good Luck!