Wide Area Network - WAN - Options my modem gives 4 options. Mine is an ADSL modem. Anyone of the following options is to be enabled. Mine is PPPoe/PPPoa - Point to Point protocol on ethernet
Dynamic IP Address Choose this option to obtain an IP address automatically from your ISP.
Static IP Address Choose this option to set static IP information provided to you by your ISP.
PPPoE/PPPoA Choose this option if your ISP uses PPPoE/PPPoA(For most DSL users).
Bridge Mode Choose this option if your ISP uses Bridge Mode.
http://www.techlineinfo.com/difference-between-pppoe-and-bridge-mode-of-adsl-modem/
" There are two ways to configure an ADSL modem for broadband connection. One in PPPoE (Point to Point Protocol over Ethernet) and the another is Bridge mode.
PPPoE Mode
In this mode the modem works as router and the PPPoE session terminates on WAN port of router. The PPPoE client is in built in the modem and allocated by BRAS server gets assigned to WAN port of modem. The Internal network has to use the private IP and for Internet access NATing happens in modem. In PPPoE mode the modem is configured in such a way that the user id and password are stored inside the Modem. Internet connection will be established as you switch on the Modem."
And bridge mode : http://mybroadband.co.za/vb/showthread.php/41951-What-is-Bridge-Mode.
"OK in short: Non bridged mode is when the DSL modem performs all the functions that allow you to connect to the internet which include: all the technical settings (VCI, encapsulation etc) and the modem also connects to the ISP with your username and Password. You can basically just connect your PC via say, Ethernet or USB, to the modem and you are connected.
Bridged mode on the other hand, allow some external device i.e. your PC or a separate router, to do the ISP connection etc. In bridge mode all the Modem does is remember your VCI, VPI and encapsulation settings. The ISP information and IP adress assigning is controlled from your separate router or PC in PPP mode.
I hope this make sense. Bridged Mode is only a modem settign option and doesn't really restrict you to do stuff!
I run a Linksys ADSL2MUE modem in bridged mode and a 3G wireless router that does the connection bit to the internet via the modem. The router also takes carre of the IP address assigments and firewall stuff... "