linux-hardened/Documentation/networking/ip_dynaddr.txt
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

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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>