Re: [lwip-users] Transport terminal Using Tcp - ask for help~

[Pomeroy, Marty]

Preamble and CRC are stripped because the ethernet chips typically don't
pass those on to the buffer (many can be configured to include the CRC).

In Wireshark, select your packet 3, and look at the top line of the
middle window.  It might say something like:
Frame 258: 54 bytes on wire (432 bits), 54 bytes captured (432 bits) on
interface 0

I'm open to it showing 60, but I'll be surprised.  On my system,
Wireshark shows padding labeled as "padding" and does not strip it.
Packets labeled with length 54 also say 54 bytes on the wire.

I'm just recommending you look at this.  On my hardware running lwIP
(NXP 1788), I have to specifically enable receiving runt frames.  And if
your ethernet chip is dropping runt frames, that would do it.

Marty