ppoe and dhcp

[Gerald Combs]

The PPPoE you get via a DSL connection is actually
PPP-over-Ethernet-over-ATM.  Telcos (including SBC) use ATM to deliver
data over a DSL line.  Ethernet is layered on top of that in order to give
the user something they can handle with an inexpensive NIC.  PPP is
layered on top of that to provide authentication and access control.

To make a short answer long, PPPoE gives you an address the same way PPP
over a dialup connection does - via IPCP.  It also lets the DSL provider
force you to authenticate using CHAP or PAP.

More info on PPPoE can be found at:

  http://www.ietf.org/rfc/rfc2516.txt
  http://www.dslreports.com/information/kb/PPPoE

Personally, I think PPPoE is a crock.  The PPP layer reduces your
effective MTU size causing problems in many cases, and the added layers
makes things harder to troubleshoot.  Other technologies exist (PPPoA,
Long-Reach Ethernet) that offer the same bandwith and price advantages
without the needless complexity.

On Mon, 27 May 2002, hanasaki wrote:

> Does PPOE give you an IP addy?  Is it just a diff way to do dhcp?
> 
> 
> 
>