linux-stable/Documentation/networking/ip_dynaddr.rst
Mauro Carvalho Chehab 9de1fcdf36 docs: networking: convert ip_dynaddr.txt to ReST
- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-28 14:39:47 -07:00

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ReStructuredText

.. 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
Enjoy!
Juanjo <jjciarla@raiz.uncu.edu.ar>