On Fri, Jul 02, 1999 at 09:32:57AM +1000, Murray Armfield wrote:
> 	I have a simple NE2000 network card which I can't get into full
> duplex. I have ifconfig.ne2 configured to use a full duplex medium using the
> keyword detected on boot. Consequentially when I go ifconfig I get media as
> full duplex but the flags tell me its in SIMPLEX and it runs as SIMPLEX. I
> know the card supports FDX and I have seen it doing it. How do I make it run
> in full duplex? Don't know if driver supports FDX.
Simplex is not the opposite of full-duplex.

I didn't find an explanation of "simplex" in any manpage, but from the
system headers (<net/if.h>):
#define IFF_SIMPLEX     0x800           /* can't hear own transmissions */

This means: The card can't receive what it sends. Full-duplex is about
receiveing foreign packages and sending at the same time.

AFAIK: You (as a user) can ignore the simplex flag, the
kernel must take care of it, so that a tcpdump (or something like
that) will show packages sent out of the interface. 
-- 
Dies ist Thilos Unix Signature! Viel Spass damit.