Some DSL providers require you to set up PPPoE tunneling for your site in order to run PPP over the providers' DSL lines and high-speed digital networks. For an overview of PPPoE, see Support for DSL Users Through PPPoE.
A PPPoE tunnel involves three participants: a consumer, a telephone company, and an ISP. You either configure PPPoE for consumers, such as PPPoE clients at your company or consumers in their homes, or you configure PPPoE on a server at an ISP.
Planning information for the PPPoE host and access server
Explanation of the PPPoE scenario that is introduced in Example of a Configuration for a PPPoE Tunnel
For tasks about setting up a PPPoE tunnel, see Chapter 20, Setting Up a PPPoE Tunnel (Tasks).
Your preconfiguration activities depend on whether you configure the client side or server side of the tunnel. In either instance, you or your organization must contract with a telephone company. The telephone company provides the DSL lines for clients, and some form of bridging and possibly an ATM pipe for access servers. In most contracts, the telephone company assembles its equipment at your site.
Personal computer or other system that is used by an individual
DSL modem, which is usually installed by the telephone company or Internet access provider
(Optional) A hub, if more than one client is involved, as is true for corporate DSL consumers
(Optional) A splitter, usually installed by the provider
Table 16-6 Planning for PPPoE Clients
Planning for a PPPoE access server involves working with the telephone company that provides your connection to its data service network. The telephone company installs its lines, often ATM pipes, at your site, and provides some sort of bridging into your access server. You need to configure the Ethernet interfaces that access the services that your company provides. For example, you need to configure interfaces for Internet access, as well as the Ethernet interfaces from the telephone company's bridge.
Table 16-7 Planning for a PPPoE Access Server
This section contains an example of a PPPoE tunnel, which is used as an illustration for the tasks in Chapter 20, Setting Up a PPPoE Tunnel (Tasks). Though the illustration shows all participants in the tunnel, you only administer one end, either the client side or server side.
Figure 16-5 Example of a PPPoE Tunnel
In the sample, MiddleCo wants to provide its employees with high-speed Internet access. MiddleCo buys a DSL package from Phone East, which, in turn, contracts with service provider Far ISP. Far ISP offers Internet and other IP services to customers who buy DSL from Phone East.
MiddleCo buys a package from Phone East that provides one DSL line for the site. The package includes a dedicated, authenticated connection to the ISP for MiddleCo's PPPoE clients. The system administrator cables the prospective PPPoE clients to a hub. Technicians from Phone East cable the hub to their DSL equipment.
eri0 – Primary network interface that connects to the local network
hme0 – Interface through which FarISP provides Internet service for its customers
hme1 – Interface contracted by MiddleCo for authenticated PPPoE tunnels
hme2 – Interface contracted by other customers for their PPPoE tunnels
Choose from the following: