blob: eacc0c780c7fd086780972786254ec583c555d71 [file] [log] [blame]
.. SPDX-License-Identifier: GPL-2.0
IP dynamic address hack-port v0.03
This stuff allows diald ONESHOT connections to get established by
dynamically changing packet source address (and socket's if local procs).
It is implemented for TCP diald-box connections(1) and IP_MASQuerading(2).
If enabled\ [#]_ and forwarding interface has changed:
1) Socket (and packet) source address is rewritten ON RETRANSMISSIONS
while in SYN_SENT state (diald-box processes).
2) Out-bounded MASQueraded source address changes ON OUTPUT (when
internal host does retransmission) until a packet from outside is
received by the tunnel.
This is specially helpful for auto dialup links (diald), where the
``actual`` outgoing address is unknown at the moment the link is
going up. So, the *same* (local AND masqueraded) connections requests that
bring the link up will be able to get established.
.. [#] At boot, by default no address rewriting is attempted.
To enable::
# echo 1 > /proc/sys/net/ipv4/ip_dynaddr
To enable verbose mode::
# echo 2 > /proc/sys/net/ipv4/ip_dynaddr
To disable (default)::
# echo 0 > /proc/sys/net/ipv4/ip_dynaddr
Juanjo <>