FPGA MAC for Point to Point Connection

Hi everyone,

I've been reading previous posts regarding ethernet MAC layers for
FPGA's but can't seem to solve my problem.

I'm going to be sending a receiving UDP packets from my PC to a PHY
chip and then to my FPGA with a mac layer that I wrote in VHDL.  It is
a point to point connection and I can successfully receive packets
when I set a static IP for the PC and broadcast.  This project will
always be point to point, is it necessary to give my FPGA board an IP
address?  I'm am worried that even if this is a point to point
connection certain applications may still try to access the same UDP
port and corrupt the transmissions.

How would I go about handshaking with the PC to let it know that there
is a valid IP address on the other end of the connection?  Currently I
am not even checking IP and it will work when I broadcast using a UDP
tester ( http://www.fpga4fun.com/files/UDP.zip ) and checking for the
port only, but when I set a specific IP it won't go through...this may
be more of a networking question but if anyone can help I would
appreciate it.

Thanks!
-Matt