NOTE: The Box Pro is deprecated and has been replaced by the camio.com/box/#1510A.
The primary NIC of the Box Pro is on the inner left as you face the back panel.
The secondary NIC is on the outer right.
The rear plate of a Box Pro is shown in the image above. The default primary NIC is the one on the inner left and the secondary NIC (disabled by default) is the one on the outer right.