Here you will find legacy drivers for Broadcom NetXtreme Ethernet controllers:
5703, 5704, 5714, 5715, 5717, 5718, 5719, 5720, 5721, 5722, 5723, 5780, 5705, 5751, 5752, 5753, 5754, 5755, 5782, 57760, 57761, 57765