[Guy Harris <guy@xxxxxxxxxxxx>]

Netfortius wrote:
> You're probably right - I do remember having been able to do something similar 
> on Linux
Linux's loopback device has a link-layer type of Ethernet; the BSD one 
doesn't.
> (not with wireshark
There's nothing Wireshark-specific about this; you'd probably see the 
same problem if you used tcpdump rather than Wireshark.
>  - but originating in tcpreplay - which defintely 
> points the problem to this one), so it is probably a kernel modification 
> and/or libnet problem with the BSD *under* MacOSX' hood ... :(
>   
What you need is a version of tcpreplay that will at least try to 
translate Ethernet packet headers to BSD loopback packet headers; you're 
unlikely ever to see a version of OS X (or any other BSD) with loopback 
devices using a link-layer type other than BPF_NULL or BPF_LOOP.