Network Communication Using Nios Daughter Board

Hi,

My partner and I are trying to implement a network bridge using the
APEX20KE Nios Development board and Nios Ethernet Daughter Board.  As
part of this network bridge we need to be able to recieve all Ethernet
packets and be able to strip the headers (which we have been able to
do).  And then create new headers, create another Ethernet packet with
the new header and send that (which we couldn't do).

I've gone over the Ethernet User Manual and all available
documentation on the Nios Ethernet Board but there is no functions
available or no means available to create my own packets and send it
(ie. without Nios having to send ARPs, etc).

We need to be able to create our own Ethernet Packets and just send it
as is (at the moment we can only use the "nr_plugs_send()" and
"nr_plugs_send_to()" functions to send, and these functions create the
Ethernet packet for us and we have no control of what goes into the
Ethernet headers).

We really need to know means to create our own Ethernet, IP and TCP or
UDP headers, for an Ethernet packet and then send it.

Anyones' assistance is most welcomed.  Thanx