Provided by: pppoe_3.5-4ubuntu1_i386 bug

NAME

       pppoe-relay - user-space PPPoE relay agent.

SYNOPSIS

       pppoe-relay [options]

DESCRIPTION

       pppoe-relay  is  a  user-space  relay  agent  for PPPoE (Point-to-Point
       Protocol over Ethernet) for Linux.  pppoe-relay works in  concert  with
       the  pppoe  client  and pppoe-server server.  See the OPERATION section
       later in this manual for details on how pppoe-relay works.

OPTIONS

       -S interface
              Adds the Ethernet interface interface to the list of  interfaces
              managed  by pppoe-relay.  Only PPPoE servers may be connected to
              this interface.

       -C interface
              Adds the Ethernet interface interface to the list of  interfaces
              managed  by pppoe-relay.  Only PPPoE clients may be connected to
              this interface.

       -B interface
              Adds the Ethernet interface interface to the list of  interfaces
              managed  by  pppoe-relay.  Both PPPoE clients and servers may be
              connected to this interface.

       -n num Allows at most num concurrent PPPoE sessions.  If not specified,
              the default is 5000.  num can range from 1 to 65534.

       -i timeout
              Specifies  the session idle timeout.  If both peers in a session
              are  idle  for  more  than  timeout  seconds,  the  session   is
              terminated.   If  timeout  is  specified  as zero, sessions will
              never be terminated because of idleness.

              Note that the idle-session expiry  routine  is  never  run  more
              frequently than every 30 seconds, so the timeout is approximate.
              The default value for timeout is 600 seconds (10 minutes.)

       -F     The  -F  option  causes  pppoe-relay  not  to  fork   into   the
              background; instead, it remains in the foreground.

       -h     The -h option prints a brief usage message and exits.

OPERATION

       pppoe-relay  listens  for  incoming PPPoE PADI frames on all interfaces
       specified with -B or -C options.  When a  PADI  frame  appears,  pppoe-
       relay  adds  a  Relay-Session-ID  tag  and  broadcasts  the PADI on all
       interfaces specified with -B or -S options  (except  the  interface  on
       which the frame arrived.)

       Any  PADO frames received are relayed back to the client which sent the
       PADI (assuming they contain valid  Relay-Session-ID  tags.)   Likewise,
       PADR  frames  from  clients  are  relayed  back  to the matching access
       concentrator.

       When a PADS frame is received, pppoe-relay enters the  two  peers’  MAC
       addresses  and session-ID’s into a hash table.  (The session-ID seen by
       the access concentrator may be different from that seen by the  client;
       pppoe-relay   must  renumber  sessions  to  avoid  the  possibility  of
       duplicate session-ID’s.)  Whenever either peer sends a  session  frame,
       pppoe-relay looks up the session entry in the hash table and relays the
       frame to the correct peer.

       When a PADT frame is received, pppoe-relay relays it to  the  peer  and
       deletes the session entry from its hash table.

       If  a  client  and  server  crash (or frames are lost), PADT frames may
       never be sent, and pppoe-relay’s hash table  can  fill  up  with  stale
       sessions.  Therefore, a session-cleaning routine runs periodically, and
       removes old sessions from the hash  table.   A  session  is  considered
       "old"  if  no  traffic  has  been  seen within timeout seconds.  When a
       session is deleted because of a timeout, a PADT frame is sent  to  each
       peer to make certain that they are aware the session has been killed.

EXAMPLE INVOCATIONS

       pppoe-relay -C eth0 -S eth1

       The  example  above  relays  frames  between  PPPoE clients on the eth0
       network and PPPoE servers on the eth1 network.

       pppoe-relay -B eth0 -B eth1

       This example is a transparent relay -- frames are relayed  between  any
       mix of clients and servers on the eth0 and eth1 networks.

       pppoe-relay -S eth0 -C eth1 -C eth2 -C eth3

       This  example  relays  frames  between  servers on the eth0 network and
       clients on the eth1, eth2 and eth3 networks.

AUTHORS

       pppoe-relay was written by David F. Skoll <dfs@roaringpenguin.com>.

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

SEE ALSO

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