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Tunnelling IP (cont)
(Details at: http://www.linuxdoc.org/HOWTO/VPN-HOWTO.html)
Tunnelling IP to make a poor man's VPN turns
the established SSH link into a "virtual modem"
connection:
/sbin/pppd sshd ssh /sbin/pppd
Work (ppp0) Encrypted Home (ppp0)
Notes:
The HOWTO has all the details. I've only done this
as a test example and have not used it extensively.
The pppd processes have to be
attached to a pseudo-terminal; std I/O won't work.
So the pppd's are opening say /dev/ttyp7 instead
of /dev/modem. This fools them into thinking it is
a real device. If the remote or local machine is not
Linux, there will be some variation of the commands.
Note, the ssh processes can also have -L and -R
redirs acting as "sidebands" in this setup. Perhaps
the sideband is used in emergencies, or for performance
reasons.