2016-09-13, 08:51
The ethernet controller is a Microchip ENC28J60 which is only 10mbit (and the SPI interface it uses can't handle much more than that anyway). Looking at the schematic and datasheet, it's also set to run half-duplex in this case (LEDB sinks to ground). Couldn't hurt to check the solder joints on the RJ45 jack and crystal Q1.