"Weird thing is the ISP gave me a different modem (4 LAN ports) before and I was on DHCP. When I moved to a new place I got this new modem (1 port)."
You're going "in all different directions at once" with your questions.
If your provider (usually ADSL) requires PPPoE ("point to point protocol over ethernet") you absolutely have to connect that way. It has less to do with DHCP (dynamic host configuration protocol) than it does with the primary "establishment of the connection".
Think of it this way. In the "old days" we used plain "modems" to connect to service providers over ordinary telephone lines. Back then, once you had the modem dial the connection, you (or your software) had to enter a username and password to authenticate your connection. Then you were "on" and ready to go. This was called "PPP" back then.
PPPoE is pretty much the same thing "over DSL". When you turn on your setup, PPPoE is used to establish and authenticate your connection (so the ISP knows that you are indeed you).
PPPoE authentication can be accomplished several ways:
- by the dsl modem itself
- by a router placed between the modem and the computer, or
- directly on the computer via software (in this case, you'd do it with the "network" preference pane in System Preferences)
OK, next issue....
Going back to the old days of dsl (again), when I first got set up (in Connecticut), the phone company provided a "dsl modem". It was nothing _more than_ a modem, and a "dumb" one, at that. That is to say, you had to enter the PPPoE info via software on the computer (back then it was OS 9 and a custom-written "connection tool" furnished by the ISP).
When I got a second computer, I got a router to place between the dsl modem and the computer (back then it was wired only, no wireless yet). With more than one computer on the "local area network" side of the router, I moved PPPoE authentication to the router itself (there's a place for that info on all routers' setup pages), and chose DHCP for my local area network.
The important thing was that I now had "two devices" between the incoming dsl signal and the Mac: a modem to handle "modem tasks" and a router to handle "router tasks". The router also offers another VERY important function: NAT ("network address translation") which provides a "hardware-based firewall" and insulates your local area computers from attempts to break in from the "outside".
Back then, ISP's could actually get disturbed if you hooked more than one computer up to a router, and might even cancel your service if they found out!
Of course, times have changed.
I think ISP's eventually came to recognize the importance of having the NAT based hardware firewall -- hence, the appearance of "combo" dsl modems/routers that have only a single LAN connection port (instead of the standard four ports you see on most routers).
But this also seems to have created connection headaches. I have a friend who got one of these with his dsl service, and over the course of several years had all kinds of problems trying to "keep the connection working smoothly". Seemed he was always making calls to tech support, reinstalling this or that, even had a few service calls.
Right away, I thought the "combo" modem/router might have been causing problems, particularly since he had a separate router installed "behind it" to add more ports.
Finally, I convinced him to let me work on it. When finished, he had a working connection and no connection problems since, and he told me I achieved what the tech people couldn't!
Here's what I did, and what I suggest you do:
Since you said you indeed have a dsl modem/1-port router, you need to do several things, in order:
1. Disconnect any "external" router, if you have one, for the time being. You want your connection to consist only of ONE computer, hooked up to the modem/router. (Aside: I'm going to _guess_ that the M/R is currently configured to do the PPPoE internally, AND that the router is set to be active).
2. The modem/router has the ability to configure it, usually accessible through either a setup application OR through a web page. What your particular one has, you will have to figure out for yourself. But there certainly _is_ a way to "set it up"
3. In the configuration area, I believe it's possible to configure it as a "router only" and set it into "bridge mode" in which the router functions are also turned off.
4. This is what you want to do. Set it up to be only a "dumb modem", that DOES NOT do the PPPoE "thing" and IS NOT a router, either (NAT turned off).
5. You will _temporarily_ have to set up the Mac to do PPPoE via the network preference pane. Do this just to verify that that connection and modem are working ok. I strongly suggest you do this BEFORE you introduce a standalone router to the setup.
6. Next, insert a router between the modem and computer, set up the router to do PPPoE and NAT, and disable the computer from doing PPPoE.
7. When done, you should have the modem reduced to doing ONLY basic modulation/demodulation of the dsl signal, with the router handling the tasks of PPPoE authentication and NAT.
Others may disagree, but I advise against trying to get a combined dsl modem/4-port router working. I just believe it's easier to "delegate" tasks between standalone devices, easier to identify and correct problems. Also, at some point you may want to upgrade your router -- can't do that with a "combo"!