I think this topic has been raised before, but with no resolution posted.
I have a network with 3 hosts. 2 are STM32H7 running LwIP under FreeRTOS, and 1 is Windows 11. All have valid IP addresses in the same sub-net. LwIP version is supplied as part of STM32 SDK, and is version 2.1.2.
When 1 (either one) of the LwIP hosts is PINGed by the Windows 11 host it responds. The sequence in Wireshark starts with Win11 making an ARP request for the MAC address on the LwIP node which is answered.
When 1 LwIP node makes an ARP request to the other there is no response. I have confirmed that the LwIP host that is supposed to be responding receives the request, and that it is processed in 'etharp_raw'.
I can confirm that the 2 LwIP hosts have different MAC addresses.
Apart from the missing padding not shown in Wireshark for Win11 both requests appear to be well formed.
Where do I look next?
BR
Simon