Hi, all,
I met a problem while testing the loopback. I used the function lwip_sendto to send a datagram to 127.0.0.1, but I cannot receive it back. After digging into the code, I found the datagram would be discarded in the function lwip_udp_input. In this function, the condition pcb->local_port == dest isn't met. I checked the whole flowchart, and I didn't find anywhere the port number of destination was modified.
By the way, I use the LWIP 1.4.
BR
Aimar