Tech Support > Computer Hardware > Routers > Is it possible to configure a Cisco 837 (SOHO 97) as an "half bridge" (or ZIPB or "dhcp spoofing") ADSL modem?
Is it possible to configure a Cisco 837 (SOHO 97) as an "half bridge" (or ZIPB or "dhcp spoofing") ADSL modem?
Posted by saratoga444in@yahoo.co.in on May 21st, 2006


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?

Posted by Merv on May 22nd, 2006



take a look at the bridiging configuration in this URL:

http://www.cisco.com/en/US/products/...html#wp1015792