Ethernet Problem

 Ethernet Problem

Hi,

I'm trying to enable my development board to communicate with a PC via Ethernet. I am able to establish a connection and send data from the PC to the micro without any issues. When I try to send data from the micro to the PC, however, the PC doesn't respond to the data. WireShark, which is a network analyzer program, sees the packet, though. I have tried both TCP and UDP with the same results. Has anyone come across the same issue? I'm using NXP's LPC1758 Cortex-M3.

Thanks,
Paul

 RE: the PC doesn't respond

What do you have running on the PC to do the response?
Are you sure it's all configured correctly?

I have found the following free simple test tools to be very useful:

TCP: http://www.simplecomtools.com/productcart/pc/viewPrd.asp?idproduct=7&idcategory=5

UDP: http://www.simplecomtools.com/productcart/pc/viewPrd.asp?idproduct=6&idcategory=5

 RE: Problem solved

Hi Andy,

I finally figured out what the problem was. When I implemented the TCP/IP stack on the micro I made a mistake in the routine that calculates the IP header checksum. With an invalid checksum Winsock just disregarded the message. Once the correct checksum was sent everything worked fine.

Thanks for all your help. I appreciate it.

Paul

 RE: a mistake in the routine that calculates the IP header checksum

Didn't Wireshark notice that?!