Each Lib has a NetWS2812 example. You can connect 7 WS2812 strips with the Arduino Boards with the Pins: 2,3,4,5,6,7,8. Pins 9,10,11,12 are for the Ethernet Shields. The network packages are send via UDP.
Hint: If you want to use a lot of WS 2812 LEDs (more than 512 LEDs), then you should use an Arduino MEGA Board, because this board has more memory for the LEDs Matrix Array. Or you can use multiple Arduino Boards.
The needed Arduino Sketches for the UNO and Mega Board you can download as a Zip-File: