Provided by: pppoe_3.12-1.2ubuntu3_amd64 bug


       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 successfully connect rather  than  try  to  pry  them  out  of  the  DSL

       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 root.

       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 along with the  name  of  your
       ISP  and  the  manufacturer  and model number of your DSL modem.  This information 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 exit.


       pppoe-sniff only works on Linux.


       pppoe-sniff was written by Dianne Skoll <>.

       The pppoe home page is


       pppd(8), pppoe(8), pppoe-sniff(8), pppoe-relay(8), /usr/share/doc/pppoe/README.Debian.gz