[Bridge] ADSL bridge Internet,DMZ and LAN

[arif at datarunding.com.my]

Hi.
My ISP has provided me with 5 fix IP. I want to set up linux bridge machine with 3 interface;

eth0 -> adsl modem(Aztech 305EU- supporting pppoe,pppoa, half bridge,bridge mode)
eth1 -> DMZ
eth2 -> LAN

My configuration.
eth0
eth1
eth2
br0 == eth0 & eth1

My problem is I can't figure out how to pass public ip to my DMZ, because lan interface on the modem is private ip. I'm a newbie. Please advice or give me link how to accomplish this.

please excuse my english as it is not my native language.