simulation of network traffic

[Dan Zehme]

Does anyone now how to have UNIX based machine (either BSD or SYSV;
the DG/UX machine I use simulates both) can be used to simulate
specific network traffic.  I would need to be able to send out
traffic under specific Ethernet addresses, and receive under
specific Ethernet addresses.  I would construct and evaluate the
entire packet through my program.  It would be preferable if this
could be done without disrupting the operation of the system itself
(for instance, by having all the Ethernet traffic that I am generating
appear on Ethernet addresses other that the ones that the system is
currently using).  Please reply directly--I do not normally subscribe
to this list.  (If there are programs that already do this, I would
be interested in them as well).

Dan Zehme, dan at tgun.webo.dg.com