title: Could I craft ethernet frame with wrong FCS/CRC?
body: <p>I want to do some testing by sending layer 2 packages with wrong FCS/CRCs.
  I've searched scapy/mz/nemesis, but it seems none of them could play with it.
  Is it possible to do this on a regular linux NIC? Or if the FCS/CRC is automatically appended by hardware that we cannot do anything with it?
  I have some specific machine to detect all incoming packets before dropping them, so I want to test if it does work like that.</p>