On 13.10.2022 12:59, Giuseppe Modugno wrote:
LPC546xx MCUs have the capability to offload checksum for IP, TCP, UDP
and ICMP, for outgoing and ingoing packets.
I enabled the generation of checksum for IPv4 for outgoing packets and
it seems working well. Now I want to enable and test checksum offload
for incoming IPv4 datagrams, but I'm in trouble how to test.
I should have the possibility to generate and send an IP datagram with
a wrong checksum from a host on the same LAN of lwip device.
Do you know of any tool that can do this kind of thing on Windows?
There are multiple ways to go, but the simplest probably is to capture
with Wireshark, save a pcap with only one packet, open that packet in a
Hex Editor (like HxD) and change its checksum (verify again with
Wireshark). Then, find a tool to send that packet back to the net. A
quick online search yields "Packet Sender" or "PReplay" for that task.