Ethernet transmission

Hi all,

I write a program to generate the ethernet packet using logic cell and implement to ENET_TXD[7:0] (i use gigabit mode). I saw the TX light on the board blinking, while I can not receive any data on my computer (I use a C socket program to receive the data). Anyone know how to fix that?

My ethernet packet is followed by this rule:

Preamble : 55 55 55 55 55 55 55

SFD: D5

Destination address: 00-26-9E-B4-DA-BB

Source address: 00-07-ED-11-80-C9

Length: 00 64

data: 00 00 ... (one hundred 00)

CRC: 6C-CC-4B-B2

I use DE3 and a HSMC-NET daughter board

Thanks!