[wecoop]

I've had trouble connecting through the AEBS, Speedstream DLS box to Earthlink using PPPoE. I get the message from the forum that I really want an ISP who supports DHCP; Earthlink tells me they do not. What ISP out there is ideal for my needs?

[ghporter]

I think the number of actual DHCP-supporting ISPs in the U.S. is countable on both hands. Maybe on just one hand. There's NOTHING wrong with PPPoE as long as your hardware supports it. The more important issue is HOW YOU handle your PPPoE authentication. Both your AEBS and your Speedstream box (along with your Mac) will log you in via PPPoE if you ask. But you MUST use ONLY ONE device to do this or you'll completely fail. If the modem lets you log into it, set it up to handle the connection. If it doesn't, set up the AEBS to do it. And make double sure that your Mac thinks it's connecting to a LAN, not via DSL-because it IS connecting to a LAN if your AEBS handles the PPPoE for you.

Not what you want to hear, I'm sure, but I think the days of "Mac friendly" versus "Mac unfriendly" ISPs are way past us. DSL using PPPoE is a standard and well accepted connection method in the U.S. and Canada (I don't know about Mexico broadband), and since Macs and other Apple products tend to be very compliant with standards, there should be no problem at all in getting online.

If you'll explain the trouble you've had connecting, we can probably point you to the right local fix that will get you going without having to change ISPs or hardware.

[wecoop]

Excellent! Your explanation is consistent with my (slowly-developing) understanding of the logic of the communication process. Would that I got smarter faster, but such is life. Thanks - I'll be back if I lapse back into confusion.

[Simon]

What's the reason for using PPPoE instead of simple DHCP? What are the advantages for the ISP? I can't think of any for the customers.

[Sherman Homan]

If I understand it correctly, PPPoE started from the Telco's dial up PPP (point to point protocol). So PPPoE runs PPP over ethernet frames instead of analog phone lines. I have found it to be much more finicky to set up, but once it is running it is OK. DHCP happens the same way whether it is fiber, cable or PPPoE. DHCP happens later in the protocol stack, on the Application layer.

[ghporter]

PPPoE has authentication, while DHCP does not. That means that theoretically anyone with a DSL modem could plug into a phone line that has DSL on it and get access, rather than the specific subscriber. It also manages connections better than DHCP; a long enough lease to keep from bugging users would be unmanageable for the ISP because users might be offline for hours or days while an address is tied up with their lease.

The advantages of PPPoE are mostly on the ISP side. They get authenticated users or idle lines instead of having to manage a huge DHCP pool that may be bogged down by users who remain offline but are still taking up an address. There is little in the "advantage" side for customers, but this protocol is so well entrenched that there are plenty of excellent "dialers" for software solutions, and every consumer level router I've ever seen handles it with aplomb (and a truly trivial amount of customer input). My PPPoE connection is on 24/7 and is often used at "odd hours," but when it requires reauthentication, my router handles it so transparently that I am completely unaware of it. I've never had a problem that was clearly "my equipment" and "PPPoE-related." I have had the ISP end forget that there was a subscriber here, slow to a crawl, or otherwise goober up, and all it took was reauthenticating to get my very high speed connection back on the fast track.

The "E" is "over ethernet" as opposed to "over ATM" which is popular in Europe. It effectively creates a tunneled ethernet connection. And yes, it can be a bit finicky to set up a PPPoE connection, but with a solid DSL signal it should be only a minor and fleeting worry. Further, you're right about where in the stack this happens; it's transport layer, not application layer, so HARDWARE can deal with it rather than software. A fine distinction? Yep. But there is a ton of equipment installed in Telco spaces all over the place that does not need direct intervention and monitoring because it simply works.

One more thing: Since PPPoE is a connection layer protocol, there is very little to haggle about in terms of implementation. This seems to be not true for DHCP. I've seen many people here complaining that a supposedly standard DHCP system at their (school, work, home, etc.) refuses to work with their Mac. Clearly, this is an issue with the implementation of DHCP, and most likely on the server side, since Apple doesn't seem to go in for this "adopt and enhance" that another, rather large computer-related company has embraced. Instead, Apple's track record is one of very close compliance and adherence with standards, much closer than other hardware and software makers.

[Big Mac]

Nearly all DSL providers use PPPoE. If you don't like that, cable's the alternative. I do recommend getting a router, no matter what type of connection it is.

[tavin64]

I have ATT yahoo dsl and it supports dhcp. Its funny because if I let my router do auto detect it sees the connection as ppoe but if I manually set it to do dhcp I get an address just fine and everything works without any problems. Who is the backend provider for your earthlink? I know in my area we have earthlink high speed as well but the backend is time warner so it works just like roadrunner.

[ghporter]

Originally Posted by tavin64 

I have ATT yahoo dsl and it supports dhcp. Its funny because if I let my router do auto detect it sees the connection as ppoe but if I manually set it to do dhcp I get an address just fine and everything works without any problems. Who is the backend provider for your earthlink? I know in my area we have earthlink high speed as well but the backend is time warner so it works just like roadrunner.

Your MODEM is providing a DHCP address to your router. AT&T is NOT providing you with such an address-it is indeed connecting you via PPPoE.

Some DSL modems allow you to configure them via an ethernet connection on the user side-you can look at all sorts of interesting stuff about your actual connection this way. In fact, most DSL modems are also single-port routers; mine is kind of old but it does that. The majority of DSL modems fielded in the U.S. are configured as network bridges, bridging the PPPoE interface to the ISP to the ethernet interface in the user's home.