This article is a good match of what I have/should/want to read and what I had to change on my home network to get the functions I want it to have. I will have to write a follow up to the last IPv6 at Home article, since the layout including the configuration got some flaws. But that will be covered in another article. For now I gonna write something about configuring PPPoE to get a working Internet Access over a Digital Subscriber Line (DSL). Please note that I use a 12.4 IOS version, as far as I know, the PPPoE configuration is a bit different (keyword vpdn) on older versions (it sure it is on 12.2, but not sure on 12.3).
Point-to-Point Protocol over Ethernet (PPPoE, defined in RFC2516) is widely used in DSL environments since the public telephone networks usually use ATM as transport protocol. So to get Ethernet over the telephone network, a protocol must be used which both transport protocols support which in that case is PPPoE.
Maybe some of you did configure a ppp connection and wondered about the new host route in the routing table after the PPP connection went alive. This is nothing to worry about since its a normal behavior of PPP and IPCP and also allows the routers to not even share the same subnet to get the line up and running.
Given the following diagram with a simple back to back connection between R4 and R5. Both interfaces have a different subnet.