[lwip-users] ARP not working

[Bernard Mentink]

Hi All,

I have just ported the lwIP stack to the NXP LPC17xx family combined with QP OS and have it mostly working except for ARP.

What works is:

1. udp_send(), udp_sendto() etc .. I han't tried tcp yet ..

2. I can ping the stack fine.

3. Receive sort of works .. explain shortly ..

To test, I created a test program on the PC that just sends x UDP packets and expects x packets from the device.

However, what I am seeing with Wireshark is that the ARP request goes out, but MOST of the time is ignored, I see no reply back from lwIP.

Occasionally the ARP is accepted and I see the packet exchange, however, I see the packet from the PC, then approx 10 seconds later (a timeout perhaps?) I see the packet from lwIP (testing with one packet).

The packets are formed correctly with IP address and port numbers ..

The only part of lwIP I have ported is the driver, so expect a problem there .... what would be best way to debug this? Anyone have some idea's?

I see you can turn on debugging in   lwipopts.h, but I don't have a UARTprintf() function implemented ....

On an aside, I am using GCC tools coupled with eclipse and openocd for development, however if I compile in debug symbols for my lwIP library the elf file created causes a GDB crash, so I can only debug through my application code

but not through the lwIP stack .... havn't found a solution to that, so am stuck.

Many thanks,

Bernie

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You always have believers and scepticts.. A True inventor is always a believer..