qemu port forward host -> guest: unable to get network access

[Nicolas BERCHER <nbercher@yahoo.fr>]

Hi,

I want to start a virtual machine and be able to connect to it from the host.  Reading the 
qemu manual, I found I have to use "-net nic" to choose both NIC MAC and model and "-net 
user" in order to define port forwards from host to guest.

I want to forward ports (tcp) this way:
  host:2564 -> guest:564
  host:2567 -> guest:567

I have a real DHCP server on the network and have associated mac=00:aa:bb:cc:dd:ee:ff to 
IP 192.168.0.96.  I'd like the guest to ask the real DHCP server to get its IP 
(192.168.0.96).  Now, I'm missing something because things do not work at all and I don't 
know how to tell qemu to use the real DHCP instead of its built-in one.  The guest doesn't 
have network access with:

  qemu -k fr -m 1G -vga std -hda plan9.disk -hdb venti.disk \
       -net nic,macaddr=00:aa:bb:cc:dd:ee:ff,model=rtl8139 \
       -net user,hostfwd=tcp::2564-192.168.0.96:564, \
                 hostfwd=tcp::2567-192.168.0.96:567

Can I use the real DCHP this way or do I have to set up a tap device?  This is kown to 
require qemu to run as root/sudo, sounds ugly to me.

Thanks for your welcoming advices,
Nicolas