Thanks for posting here! The Plugable Fast Ethernet Adapter USB2-E100 is the USB Ethernet Adapter that the Toshiba Thrive with Android 3.2.1 has support for.
You only need to plug in the Plugable Fast Ethernet Adapter USB2-E100, connect a live Ethernet cable and wait for a couple of minutes for auto-configuration of the network settings. The Link and Power LEDs on the device will light up and you will have connectivity.
If this is the adapter that you have ordered and you do not see this behavior, let’s figure out what could be going wrong here.
Some quick questions-:
Could you post back and confirm the version of Android on your Toshiba Thrive?
What is connected on the other side of the Ethernet cable plugged in the Plugable USB2-E100? Is it a switch, router, modem,…?
If you try to open the browser or any app that requires Internet connectivity what behavior do you see on the Power and Link LEDs on the Plugable USB2-E100?
Once you post back with this information, we will figure out the next steps.
Thanks for your patience while we figure this out!