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LAUNCHXL2-RM57L: LWIP: UDP packets receive information

Part Number: LAUNCHXL2-RM57L

Hi All,
Currently, we are checking the LWIP Active server Demo program UDP packet for Launchpad XL2-RM57 board.

Below are the details,
 Launchpad Board XL2-RM57 <=> Laptop using the cross cable directly. There is no external switch (or) router connected.
         My Laptop is not connected with any other external network apart from the Launchpad XL2-RM57.
 Launchpad XL2 RM57 IP address=169.254.0.1
 Launchpad XL2 RM57 MAC address=00:08:EE:03:A6:6C
 Laptop IP address=169.254.226.247
 LWIP_AUTOIP(Auto IP configuration Enabled)/LWIP_SNMP enabled.
 UDP Port number=161

I am sending the customised UDP packet using Packet Sender Tool.
There is no error in LWIP_STATS with respect to UDP packet info.(Eg:  Length/Check sum/Memory)
In debug mode, I have captured, P->Payload data information from the memory view.
Please find the attached screenshot of UDP packet(sending via Packet Sender Tool) & Debug Memory view of
received data packets(P->Payload)
Does the received UDP packet correct ? Inorder to ensure the received UDP packet correctness, Do I need to check any other function (or) variable?

Kindly give your valuable feedback.

Regards,
S.Saravanakumar

                

  • The received packet is correct. But the payload address in expression window might not be correct. This address is the packet address.

    The 1st two bytes (0x0800904A~0x0800904B) are source port: 0xC509 = 50441, the 2nd two byes (0x0800904C~0x0800904D) are destination port: 0x00A1=161

    The 3rd two bytes (0x0800904E~0x0800904F) are length: 0x0012=18; the 4th two bytes (0x08009050~0x08009051) are checksum

    The following bytes are payload (10 bytes): 0x00, 0x01,...0x09

    Total length = 2+2+2+2+10=18 bytes