hello forum im using uvision V4.6.0.0 with MDK-ARM professional Version:4.60.0.0 toolchain. i want to test RL-TCPnet with LPC1768 micro and DP83848C PHY Transiver (i have designed a board myself as the same as your MCB17xx board). i have loaded your LEDSwitch Example into my micro and it works fine and i can send and recive data through UDP socket and i can control LED in my board. i want to know in this example Ethernet controller works in Polling mode or interrupt mode??? my problem is that im using SPI bus in slave mode with interrupt service routin that i recive some datas from other controller(DSP)continuously and it works too but every time that i recive other packet through LAN my SPI peripheral hangs and dont recive other datas. could you let me know how can i solve this problem? im waiting for your answer. best regards. thanks.