pppoe-relay - user-space PPPoE relay agent.


   pppoe-relay [options]


   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.


   -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.


   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

   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.


   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.


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

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


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


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