This is the README file for tinc version 1.0pre3. Installation
instructions may be found in the INSTALL file.

tinc is Copyright (C) 1998,1999,2000 Ivo Timmermans
<itimmermans@bigfoot.com>, Guus Sliepen <guus@sliepen.warande.net> and
others. For a complete list of authors see the AUTHORS file.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version. See the file COPYING for more details.


Security statement
------------------

In august 2000, we discovered the existence of a security hole in all
versions of tinc up to and including 1.0pre2. This had to do with the
way we exchanged keys. Since then, we have been working on a new
authentication scheme to make tinc as secure as possible. The current
version uses the OpenSSL library and does authentication in much the
same way as the SSH protocol does.

Cryptography is a hard thing to get right. We cannot make any
guarantees. Time, review and feedback are the only things that can
prove the security of any cryptographic product. If you wish to review
tinc or give us feedback, you are stronly encouraged to do so.


Requirements
------------

Since 1.0pre3, we use OpenSSL for all cryptographic functions.  So you
need to install this library first; grab it from
http://www.openssl.org/.  We recommend version 0.9.5 or better.  If
this library is not installed on you system, configure will fail.  The
manual in doc/tinc.texi contains more detailed information on how to
install this library.


Features
--------

This version of tinc supports multiple virtual networks at once. To
use this feature, you may supply a netname via the -n or --net
options. The standard locations for the config files will then be
/etc/tinc/<net>/. Because of this feature, tinc will send packets
directly to their destinations, instead of to the uplink. If this
behaviour is undesirable (for instance because of firewalls or other
restrictions), please use an older version of tinc (I would recommend
tinc-0.2.19).

In order to force the kernel to accept received packets, the
destination MAC address will be set to FE:FD:00:00:00:00 upon
reception. The MAC address of the ethertap or tun/tap interface must
also be set to this address. See the manual for more detailed
information.

tincd regenerates its encryption key pairs. It does this on the first
activity after the keys have expired. This period is adjustable in the
configuration file, and the default time is 3600 seconds (one hour).

This version supports multiple subnets at once. They are also sorted
on subnet mask size. This means that it is possible to have
overlapping subnets on the VPN, as long as their subnet mask sizes
differ.