On Sun, Apr 15, 2007 at 01:24:49AM -0700, Bryan Phillippe wrote:
> Hello,
> 
> I would like to conduct some ethernet network testing using a NetBSD  
> client & server configuration.  The unusual part about this is that I  
> want my configuration to be a single NetBSD system functioning as  
> both a client and a server, physically sending network traffic out on  
> interface and back into another, using a cross-cable.
> 
> I initially attempted to set this up on a Linux system, but any  
> configuration I could devise was still defeated by the routing code,  
> which knew that the destination was ultimately "local" and would  
> "receive" the traffic without ever physically sending it.  AFAICT,  
> making it work the way I want would have required a convoluted  
> iptables configuration or a kernel patch.  I'm hoping the NetBSD team  
> has already provided a knob for doing this on NetBSD!

I suspect NetBSD will do the same. You may be able to work around this
by manualy fixing (deleting) the route entries, or playing with
ipfiler.
But the easiest way to do this would be to use Xen ...

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--