Re: [lwip-users] ICMP sporadic answer after some time

[Sergio R. Caprile]

I bet your driver is missing frames by letting them sleeping inside the 
chip as many do, but you have a lot of unknown variables.
Is there any other traffic in your network ?
Is the TCP app running while you ping your hardware ?
Did you try the same with a known good application like the examples 
instead of your own (and probably buggy and/or memory trashing) app ?
Did you see a wireshark capture file ? Can you do and post one ? You 
must know if either lwIP does not see the pings or the responses are 
trashed or missing.
Have you debugged the input ? You can put breakpoints and see if the 
frames are being received and delivered to the stack or not.
Do you use an OS or is it bare metal ? NO_SYS = ?
Atmel has been nice so far, but you should check your port behaves 
properly: all calls to lwIP functions on the same context, either all 
interrupts or all main loop, no mixes. If you run an OS, all your calls 
to lwIP raw API functions must be from the same thread that runs the 
rest of the stack, that is, all in a single thread.