Documentation/networking/ip_dynaddr.txt

   1 IP dynamic address hack-port v0.03
   2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   3 This stuff allows diald ONESHOT connections to get established by
   4 dynamically changing packet source address (and socket's if local procs).
   5 It is implemented for TCP diald-box connections(1) and IP_MASQuerading(2).
   6
   7 If enabled[*] and forwarding interface has changed:
   8   1)  Socket (and packet) source address is rewritten ON RETRANSMISSIONS
   9       while in SYN_SENT state (diald-box processes).
  10   2)  Out-bounded MASQueraded source address changes ON OUTPUT (when
  11       internal host does retransmission) until a packet from outside is
  12       received by the tunnel.
  13
  14 This is specially helpful for auto dialup links (diald), where the
  15 ``actual'' outgoing address is unknown at the moment the link is
  16 going up. So, the *same* (local AND masqueraded) connections requests that
  17 bring the link up will be able to get established.
  18
  19 [*] At boot, by default no address rewriting is attempted.
  20   To enable:
  21      # echo 1 > /proc/sys/net/ipv4/ip_dynaddr
  22   To enable verbose mode:
  23      # echo 2 > /proc/sys/net/ipv4/ip_dynaddr
  24   To disable (default)
  25      # echo 0 > /proc/sys/net/ipv4/ip_dynaddr
  26
  27 Enjoy!
  28
  29 -- Juanjo  <jjciarla@raiz.uncu.edu.ar>