My ISP requires using PPPOE to connect to the internet but I don't know how to add the PPPOE to my new N800 (upgraded to OS2008). Can any experts help? Thanks.

PPPOE configuration is done in the router, not the N800.

Thanks. But my ISP requires me to log in with a pppoe dialer (when I use mac, I have to run the dialer & key in username & password). I don't know what kind of pppoe dialer should be installed in N800 & don't know how to install (I've only a little bit knowledge about Linux. N800 is using Debian but a brief / mini version, right?) Thanks again.

If you want internet on your N800 using your ISP, then you need a wifi router.
1. Do you have one?
2. If so, is your Mac connected to the ISP's internet modem directly, or
3. Is your Mac connected to the wired port of the router, and connected to the internet via the router's DHCP server? If so, then you must have already setup the PPPOE in the router config itself.
Please give some more detail on your setup.

Yep, the preferred configuration for this is to use either a modem plus ppoe-capable router, or an integrated dsl modem/pppoe-capable router (e.g. the common Thomson ones they often give out for free with broadband services). Then there's just a question of configuring the router, and nothing to do on the computers. Safer too, because you have that additional router (if it's got a firewall too - if not, put one in between) in front of the computer(s).

Usually PPPOA is done on the _router_
PPPOE is an end to end (means an encapsulation client is needed on the device) that has to pass through a modem/bridge.

In practice, a _router_ (with IP adress) can established the pppoe connection but I've never seen this. Well, last time I had internet at home was 4 years ago..

Still a pppoe client could be handful on the nokias.. for people with modem/bridge

free: My sister has a setup with PPPOE in the _router_. There's no conflict with it being and end-to-end protocol, after all it's simply Ethernet encapsulated over PPP. The router is the single IP seen by the ISP, the modem/router in turn uses DHCP plus NAT to talk to your in-house computers.

Thanks everybody. I'm in Hong Kong where internet services for non-commercial users (at a lower cost) are dynamic IP addresses. So most most (if not all) users should "dial-up" with some sort of a small program before connecting to the service (before "dialing", one can connect to the ISP but cannot really connect to the internet).

No matter whether my mac book is connected to a wireless router or with a wired connection, I should run a rp-pppoe program and key in "user name" & "password" for my ISP to identify that I am a paid user.

But I'll explore if I can configure my wireless router to do the pppoe dialing and then share with all my experience. Thanks.

Yes, modem/router != modem/bridge.
Was this delivered/rented by the ISP directly?
I remembered at the time when they said on the contract that your not allowed to put more than one box between each subscription. For average joe, with a modem/bridge it was harder to do as they had to setup their PC as a gateway for the others. Maybe this plus the price of a router is why the ISP were not giving it with the subscription.
Anyway
PPP=point to point network
Over
Ether=diffusion network

The modem/router came from the ISP, originally it wasn't PPPOE. Then the ISP was bought by another ISP which use PPPOE everywhere, for all the old customers they sent out a CD to execute from the PC, it ran a program which reprogrammed the modem/router (for those of the customers who preferred to continue using the modem given to them by the old ISP) to PPPOE. After that it was just plug and play as before (i.e. dhcp to get an IP from the modem. My sister connected a wi-fi/wired router to it and connected everything else to that).