I have made the driver for enc28j60 for LPC1788 and I'm trying to send UDP message to LPC via wifi enabled device (iOS, windows over wifi). But transmission fails. Wifi device sends the ARP request. LPC sends the response, but it doesn't arrive. I have checked the ARP cache on windows machine and it stayed empty. When I do the same with cable connected machine, it arrives correctly, ARP cache is populated. That concludes that ARP response is sent and it is correctly built.

I have tried ping as well and same thing, every device that comes via router failed to get ARP response, but devices that are connected by cable receives the ARP response.

But, same enc28 board is working fine with Arduino. Arduino implementation of driver and ethernet was not done by me.

That means that it is somehow related to the driver. I have either forgot to switch some option of enc28 chip or ...

I have looked at Arduino driver but I could not find any obvious error in my implementation.

Any idea what could be wrong?