TCP/IP implementation in Virtex 4

Hi!

I am facing a new design based in FPGA that needs to communicate over Ethernet using TCP/IP. Moreover I would need to implement DHCP, ARP and ICMP.

For the rest of the application itself an Spartan can do the job without problem. But as I need an Ethernet port I am considering if its meaningful to upgrade it to a Virtex 4 with Ethernet embedded port. So I am considering two options:

1- Use Spartan 3 + Ethernet embedded module (Rabbit Semiconductor, Tini, Wiznet...)
2- Use Virtex 4 FX12 and implement the Ethernet port.

Of course I cannot pay any IP (GSRD, TEMAC...). I want to communicate using 100-BASE-TX.

My idea if implementing TCP over Virtex 4 was to program the protocol inside the Power PC processor embedded in the FX12 as I think it will be easier to implement than using VHDL. What do you think?

Any of you have already faced with a similar problem?

I am fraid about the quantity of time that I can spend to implement the Ethernet port. Any idea?

Please any advice is wellcome!

Thanks!

OscarM