| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |