Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (Debian-3.1)
Apropos / Subsearch:
optional field

PPPOE-SNIFF(8)              System Manager's Manual             PPPOE-SNIFF(8)

       pppoe-sniff - examine network for non-standard PPPoE frames

       pppoe-sniff [options]

       pppoe-sniff  listens  for  likely-looking PPPoE PADR and session frames
       and deduces extra options required for pppoe(8) to work.

       Some DSL providers seem to  use  non-standard  frame  types  for  PPPoE
       frames,  and/or  require a certain value in the Service-Name field.  It
       is often easier to sniff those values from a machine which can success-
       fully connect rather than try to pry them out of the DSL provider.

       To use pppoe-sniff, you need two computers, a DSL modem and an Ethernet
       hub (not an Ethernet switch.)

       If the DSL modem normally connects directly to your computer's Ethernet
       card,  connect  it  to the "uplink" port on the Ethernet hub.  Plug two
       computers into normal ports on the hub.  On one computer, run  whatever
       software the DSL provider gave you on whatever operating system the DSL
       provider supports.  On the other computer, run  Linux  and  log  in  as

       On  the Linux machine, put the Ethernet interface into promiscuous mode
       and start pppoe-sniff.  If the ethernet interface is eth0, for example,
       type these commands:

            ifconfig eth0 promisc
            pppoe-sniff -I eth0

       On  the  other  machine,  start  your DSL connection as usual.  After a
       short time, pppoe-sniff should print recommendations for the  value  of
       PPPOE_EXTRA.   Set  this  value in /etc/ppp/pppoe.conf.  If pppoe-sniff
       indicates that something special is required in PPPOE_EXTRA, please  e-
       mail  this  to pppoe@roaringpenguin.com along with the name of your ISP
       and the manufacturer and model number of your DSL modem.  This informa-
       tion  will be collated and provided on the PPPoE web page for users who
       do not have two computers.

       After pppoe-sniff finishes (or you stop it if it seems hung),  remember
       to turn off promiscuous mode:

            ifconfig eth0 -promisc

       -I interface
              The  -I  option  specifies the Ethernet interface to use.  Under
              Linux, it is typically eth0 or eth1.  The  interface  should  be
              "up" and in promiscuous mode before you start pppoe-sniff.

       -V     The -V option causes pppoe-sniff to print its version number and

       pppoe-sniff only works on Linux.

       pppoe-sniff was written by David F. Skoll <dfsATroaringpenguin.com>.

       The pppoe home page is http://www.roaringpenguin.com/pppoe/.

       pppd(8),        pppoe(8),        pppoe-sniff(8),        pppoe-relay(8),

4th Berkeley Distribution         3 July 2000                   PPPOE-SNIFF(8)