Can you tell us why you are needing PPPoE, Is it to connect to a DSL connection?
If so who is your provider?
Can you also tell u what model of Airport you are using?
Let us know
When I attempt to connect to the internet with my laptop (I have a Vaio and my wife has a MacBook) I am not able to connect. I can sign onto our network, but I am still not able to connect to the internet. I contacted my DSL provider, they looked and saw there is a good connection with the modem and said my PPPoE needs to be configured and told me they don't help with that. The airport is an Airport Express Base Station from Mac.
In that case can you open the Airport assistant then click Set up an AirPort Base Station and click Continue.
Next click the arrow box on the Available AirPort networks list and choose your AirPort and click the Continue button.
Enter your password XXXXX hit Continue and select I am using another Internet Service Provider and click continue
Select Cable Modem or DSL using PPP over Ethernet (PPPoE) and hit continue.
In the Account Name field type username and then enter your password XXXXX click the arrow box on the Disconnect after pop-up list and choose Never then check the box next to Automatically connect and click Continue.
Next follow the prompts to name and configure your wireless network and its security settings then hit continue again.
Once you have done that you should be able to connect your machine to your wireless network and get online.
If you are unable let us know who is your Internet provider.