From 9de1fcdf36e7e00693a260865a5f2a58af1c7040 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 28 Apr 2020 00:01:46 +0200 Subject: 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 Signed-off-by: David S. Miller --- Documentation/networking/ip_dynaddr.rst | 40 +++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 Documentation/networking/ip_dynaddr.rst (limited to 'Documentation/networking/ip_dynaddr.rst') diff --git a/Documentation/networking/ip_dynaddr.rst b/Documentation/networking/ip_dynaddr.rst new file mode 100644 index 000000000000..eacc0c780c7f --- /dev/null +++ b/Documentation/networking/ip_dynaddr.rst @@ -0,0 +1,40 @@ +.. 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 -- cgit v1.2.3