Re: [lwip-users] Ping with data greater than 1472 bytes

[Sergio R. Caprile]

Who pings who ? Who is who ?
Assuming both your MTUs are 1500 bytes, greater than 1472 means the
payload will not fit in a single IP datagram over a single Ethernet
frame. (20IP + 8ICMP + 1472payload = 1500)
Your sender will have to fragment and your receiver will have to
reassemble. Perhaps one of them, or both, are not enabled or
non-feasible. Probably unlikely but, one of them might send jumbo frames ?
Wireshark capture, analyze.
Breakpoint, debug.

I personally do not know if lwIP handles fragmentation for ICMP payloads
in either direction.