Hello,

I am attempting to receive corrupted Ethernet frames. I am using ethtool disable rx FCS checking(ethtool -K eth0 rx-all on).

Unfortuantly, my Ethernet card does not support this operation, when I display all my eth0 info (ethtool -k eth0) I see that:

rx-all off [fixed]

I believe this means I need a ethenet card that support modification of this variable, Does anyone know of a USB/Ethernet dongle that supports this operation? I believe the RealTek R111 card supports the operation but I would rather not start messing with the computer internals. Furthermore does the OS you are running have any effect on these configurations? I have seen in a wireshark forum that running FreeBSD may enable these features?

Thanks in advance!

Most NIC card support the feature, sending corrupted frame to CPU. Some driver drop these frame.

I must be the unluckiest man alive then because I have tried 3 different PC's, a raspberry pi, and 3 UBS/Ethernet dongles with different Ethernet Cards and none of them support the option. generally you can ignore the IP CRC fairly easily but the layer 2 FCS seems to be fixed on everything I have tried. Do you know which Ethernet cards/ Ethernet dongles support this operation?

Thank you for the help.

For layer 2 FCS error, it is complicated. I forget which one support it, not all.
But I am interested of why do know to see these frame's content. Isn't the drop counter good enough?

I need to characterize the corruption of the data due to specific events. To do this i need to compare known sent data to corrupted received data, thus I need to view Ethernet frames that do not pass the FCS check.

You could receive frame of FCS error. But most NIC doesn't support to pass other type of corrupted frame, just providing counter only.