Is it possible to configure a Cisco 837 (SOHO 97) as an "half bridge" (or ZIPB or "dhcp spoofing") ADSL modem?

Hi,

my ADSL connection is a dynamic IP, public IP, PPPoA (no, PPPoE is not available) connection. I would like to use my Cisco 837 as an "half bridging" ADSL modem, a functionality that many cheap ADSL modem/routers have: is it possible to configure it in a such way?

"Half brigding" (sometimes called "dhcp spoofing" or ZIPB or "zero IP bridging") makes possible to assign the IP address you obtain from your provider (the only one it gives you) to some host on your DMZ/LAN (maybe a more powerfull router) without any NAT on the ADSL modem.

Here is how it works:

1) the ADSL modem connects to the internet provider using PPPoA and obtains a (dynamic) public IP address

2) the ADSL modem's DHCP server listens on the LAN (of course the modem has to have an ethernet port) and gives the public IP address (the one obtained upon connection) to any LAN client who requests one

3) the ADSL modem forwards the traffic destinated to the public IP from the ATM interface to the LAN, and viceversa... without any NAT!

So, is it possible to configure my Cisco to act like this?