\input texinfo @c -*-texinfo-*-
-@c $Id: tinc.texi,v 1.8.4.16 2001/05/24 20:24:12 guus Exp $
@c %**start of header
@setfilename tinc.info
@settitle tinc Manual
@setchapternewpage odd
@c %**end of header
+@include tincinclude.texi
+
@ifinfo
+@dircategory Networking tools
@direntry
* tinc: (tinc). The tinc Manual.
@end direntry
-This is the info manual for tinc, a Virtual Private Network daemon.
-
-Copyright @copyright{} 1998-2001 Ivo Timmermans
-<itimmermans@@bigfoot.com>, Guus Sliepen <guus@@sliepen.warande.net> and
-Wessel Dankers <wsl@@nl.linux.org>.
+This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
-$Id: tinc.texi,v 1.8.4.16 2001/05/24 20:24:12 guus Exp $
+Copyright @copyright{} 1998-2009 Ivo Timmermans,
+Guus Sliepen <guus@@tinc-vpn.org> and
+Wessel Dankers <wsl@@tinc-vpn.org>.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
@page
@vskip 0pt plus 1filll
-@cindex copyright
-Copyright @copyright{} 1998-2001 Ivo Timmermans
-<itimmermans@@bigfoot.com>, Guus Sliepen <guus@@sliepen.warande.net> and
-Wessel Dankers <wsl@@nl.linux.org>.
+This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
-$Id: tinc.texi,v 1.8.4.16 2001/05/24 20:24:12 guus Exp $
+Copyright @copyright{} 1998-2009 Ivo Timmermans,
+Guus Sliepen <guus@@tinc-vpn.org> and
+Wessel Dankers <wsl@@tinc-vpn.org>.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
@end titlepage
+@ifnottex
@c ==================================================================
-@node Top, Introduction, (dir), (dir)
+@node Top
+@top Top
@menu
-* Introduction:: Introduction
+* Introduction::
* Preparations::
* Installation::
* Configuration::
* Running tinc::
* Technical information::
+* Platform specific information::
* About us::
* Concept Index:: All used terms explained
@end menu
-
-
-@contents
+@end ifnottex
@c ==================================================================
-@node Introduction, Preparations, Top, Top
+@node Introduction
@chapter Introduction
@cindex tinc
-tinc is a Virtual Private Network (VPN) daemon that uses tunneling and
+Tinc is a Virtual Private Network (VPN) daemon that uses tunneling and
encryption to create a secure private network between hosts on the
Internet.
process of tinc itself.
@menu
-* VPNs:: Virtual Private Networks in general
-* tinc:: about tinc
+* Virtual Private Networks::
+* tinc:: About tinc
* Supported platforms::
@end menu
@c ==================================================================
-@node VPNs, tinc, Introduction, Introduction
+@node Virtual Private Networks
@section Virtual Private Networks
@cindex VPN
@c ==================================================================
-@node tinc, Supported platforms, VPNs, Introduction
+@node tinc
@section tinc
@cindex vpnd
Guus' idea. He wrote a simple implementation (about 50 lines of C) that
used the ethertap device that Linux knows of since somewhere
about kernel 2.1.60. It didn't work immediately and he improved it a
-bit. At this stage, the project was still simply called @samp{vpnd}.
+bit. At this stage, the project was still simply called "vpnd".
Since then, a lot has changed---to say the least.
@cindex tincd
-tinc now supports encryption, it consists of a single daemon (tincd) for
+Tinc now supports encryption, it consists of a single daemon (tincd) for
both the receiving and sending end, it has become largely
runtime-configurable---in short, it has become a full-fledged
professional package.
-@cindex Traditional VPNs
+@cindex traditional VPNs
@cindex scalability
-tinc also allows more than two sites to connect to eachother and form a single VPN.
+Tinc also allows more than two sites to connect to eachother and form a single VPN.
Traditionally VPNs are created by making tunnels, which only have two endpoints.
Larger VPNs with more sites are created by adding more tunnels.
-tinc takes another approach: only endpoints are specified,
+Tinc takes another approach: only endpoints are specified,
the software itself will take care of creating the tunnels.
This allows for easier configuration and improved scalability.
@c ==================================================================
-@node Supported platforms, , tinc, Introduction
+@node Supported platforms
@section Supported platforms
@cindex platforms
-tinc has been verified to work under Linux, FreeBSD and Solaris, with
-various hardware architectures. These are the three platforms
-that are supported by the universial TUN/TAP device driver, so if
-support for other operating systems is added to this driver, perhaps
-tinc will run on them as well. Without this driver, tinc will most
+Tinc has been verified to work under Linux, FreeBSD, OpenBSD, NetBSD, MacOS/X (Darwin), Solaris, and Windows (both natively and in a Cygwin environment),
+with various hardware architectures. These are some of the platforms
+that are supported by the universal tun/tap device driver or other virtual network device drivers.
+Without such a driver, tinc will most
likely compile and run, but it will not be able to send or receive data
packets.
@cindex release
-The official release only truly supports Linux.
For an up to date list of supported platforms, please check the list on
our website:
-@uref{http://tinc.nl.linux.org/platforms.html}.
-
-
-@c ==================================================================
-@subsection Linux
-
-@cindex Linux
-tinc was first written for Linux running on an intel x86 processor, so
-this is the best supported platform. The protocol however, and actually
-anything about tinc, has been rewritten to support random byte ordering
-and arbitrary word length. So in theory it should run on other
-processors that Linux runs on. It has already been verified to run on
-alpha and sparc processors as well.
-
-tinc uses the ethertap device or the universal TUN/TAP driver. The former is provided in the standard kernel
-from version 2.1.60 up to 2.3.x, but has been replaced in favour of the TUN/TAP driver in kernel versions 2.4.0 and later.
-
-
-@c ==================================================================
-@subsection FreeBSD
-
-@cindex FreeBSD
-tinc on FreeBSD relies on the universial TUN/TAP driver for its data
-acquisition from the kernel. Therefore, tinc will work on the same platforms
-as this driver. These are: FreeBSD 3.x, 4.x, 5.x.
-
-
-@c ==================================================================
-@subsection Solaris
-
-@cindex Solaris
-tinc on Solaris relies on the universial TUN/TAP driver for its data
-acquisition from the kernel. Therefore, tinc will work on the same platforms
-as this driver. These are: Solaris, 2.1.x.
-
+@uref{http://www.tinc-vpn.org/platforms}.
@c
@c
@c
@c ==================================================================
-@node Preparations, Installation, Introduction, Top
+@node Preparations
@chapter Preparations
This chapter contains information on how to prepare your system to
@c ==================================================================
-@node Configuring the kernel, Libraries, Preparations, Preparations
+@node Configuring the kernel
@section Configuring the kernel
-@cindex RedHat
-@cindex Debian
-@cindex netlink_dev
-@cindex tun
-@cindex ethertap
-If you are running Linux, chances are good that your kernel already supports
-all the devices that tinc needs for proper operation. For example, the
-standard kernel from Redhat Linux already has support for ethertap and netlink
-compiled in. Debian users can use the modconf utility to select the modules.
-If your Linux distribution supports this method of selecting devices, look out
-for something called `ethertap', and `netlink_dev' if it is using a kernel
-version prior to 2.4.0. In that case you will need both these devices. If you
-are using kernel 2.4.0 or later, you need to select `tun'.
-
-@cindex Kernel-HOWTO
-If you can install these devices in a similar manner, you may skip this section.
-Otherwise, you will have to recompile the kernel in order to turn on the required features.
-If you are unfamiliar with the process of configuring and compiling a new kernel,
-you should read the @uref{http://howto.linuxberg.com/LDP/HOWTO/Kernel-HOWTO.html, Kernel HOWTO} first.
-
@menu
-* Configuration of Linux kernels 2.1.60 up to 2.4.0::
-* Configuration of Linux kernels 2.4.0 and higher::
+* Configuration of Linux kernels::
* Configuration of FreeBSD kernels::
+* Configuration of OpenBSD kernels::
+* Configuration of NetBSD kernels::
* Configuration of Solaris kernels::
+* Configuration of Darwin (MacOS/X) kernels::
+* Configuration of Windows::
@end menu
@c ==================================================================
-@node Configuration of Linux kernels 2.1.60 up to 2.4.0, Configuration of Linux kernels 2.4.0 and higher, Configuring the kernel, Configuring the kernel
-@subsection Configuration of Linux kernels 2.1.60 up to 2.4.0
+@node Configuration of Linux kernels
+@subsection Configuration of Linux kernels
+@cindex Universal tun/tap
+For tinc to work, you need a kernel that supports the Universal tun/tap device.
+Most distributions come with kernels that already support this.
Here are the options you have to turn on when configuring a new kernel:
@example
Code maturity level options
[*] Prompt for development and/or incomplete code/drivers
-Networking options
-[*] Kernel/User netlink socket
-<M> Netlink device emulation
Network device support
-<M> Ethertap network tap
+<M> Universal tun/tap device driver support
@end example
-If you want to run more than one instance of tinc or other programs that use
-the ethertap, you have to compile the ethertap driver as a module, otherwise
-you can also choose to compile it directly into the kernel.
+It's not necessary to compile this driver as a module, even if you are going to
+run more than one instance of tinc.
-If you decide to build any of these as dynamic kernel modules, it's a good idea
-to add these lines to @file{/etc/modules.conf}:
+If you decide to build the tun/tap driver as a kernel module, add these lines
+to @file{/etc/modules.conf}:
@example
-alias char-major-36 netlink_dev
-alias tap0 ethertap
-options tap0 -o tap0 unit=0
-alias tap1 ethertap
-options tap1 -o tap1 unit=1
-...
-alias tap@emph{N} ethertap
-options tap@emph{N} -o tap@emph{N} unit=@emph{N}
+alias char-major-10-200 tun
@end example
-Add as much alias/options lines as necessary.
+
+@c ==================================================================
+@node Configuration of FreeBSD kernels
+@subsection Configuration of FreeBSD kernels
+
+For FreeBSD version 4.1 and higher, tun and tap drivers are included in the default kernel configuration.
+Using tap devices is recommended.
@c ==================================================================
-@node Configuration of Linux kernels 2.4.0 and higher, Configuration of FreeBSD kernels, Configuration of Linux kernels 2.1.60 up to 2.4.0, Configuring the kernel
-@subsection Configuration of Linux kernels 2.4.0 and higher
+@node Configuration of OpenBSD kernels
+@subsection Configuration of OpenBSD kernels
-Here are the options you have to turn on when configuring a new kernel:
+For OpenBSD version 2.9 and higher,
+the tun driver is included in the default kernel configuration.
+There is also a kernel patch from @uref{http://diehard.n-r-g.com/stuff/openbsd/}
+which adds a tap device to OpenBSD which should work with tinc,
+but with recent versions of OpenBSD,
+a tun device can act as a tap device by setting the link0 option with ifconfig.
-@example
-Code maturity level options
-[*] Prompt for development and/or incomplete code/drivers
-Network device support
-<M> Universal TUN/TAP device driver support
-@end example
+@c ==================================================================
+@node Configuration of NetBSD kernels
+@subsection Configuration of NetBSD kernels
-It's not necessary to compile this driver as a module, even if you are going to
-run more than one instance of tinc.
+For NetBSD version 1.5.2 and higher,
+the tun driver is included in the default kernel configuration.
-If you have an early 2.4 kernel, you can choose both the TUN/TAP driver and the
-`Ethertap network tap' device. This latter is marked obsolete, and chances are
-that it won't even function correctly anymore. Make sure you select the
-universal TUN/TAP driver.
+Tunneling IPv6 may not work on NetBSD's tun device.
-If you decide to build the TUN/TAP driver as a kernel module, add these lines
-to @file{/etc/modules.conf}:
-@example
-alias char-major-10-200 tun
-@end example
+@c ==================================================================
+@node Configuration of Solaris kernels
+@subsection Configuration of Solaris kernels
+
+For Solaris 8 (SunOS 5.8) and higher,
+the tun driver may or may not be included in the default kernel configuration.
+If it isn't, the source can be downloaded from @uref{http://vtun.sourceforge.net/tun/}.
+For x86 and sparc64 architectures, precompiled versions can be found at @uref{http://www.monkey.org/~dugsong/fragroute/}.
+If the @file{net/if_tun.h} header file is missing, install it from the source package.
@c ==================================================================
-@node Configuration of FreeBSD kernels, Configuration of Solaris kernels, Configuration of Linux kernels 2.4.0 and higher, Configuring the kernel
-@subsection Configuration of FreeBSD kernels
+@node Configuration of Darwin (MacOS/X) kernels
+@subsection Configuration of Darwin (MacOS/X) kernels
-This section will contain information on how to configure your FreeBSD
-kernel to support the universal TUN/TAP device. For 5.0 and 4.1
-systems, this is included in the kernel configuration, for earlier
-systems (4.0 and 3.x), you need to install the universal TUN/TAP driver
-yourself.
+Tinc on Darwin relies on a tunnel driver for its data acquisition from the kernel.
+Tinc supports either the driver from @uref{http://tuntaposx.sourceforge.net/},
+which supports both tun and tap style devices,
+and also the driver from from @uref{http://chrisp.de/en/projects/tunnel.html}.
+The former driver is recommended.
+The tunnel driver must be loaded before starting tinc with the following command:
-Unfortunately somebody still has to write the text.
+@example
+kmodload tunnel
+@end example
@c ==================================================================
-@node Configuration of Solaris kernels, , Configuration of FreeBSD kernels, Configuring the kernel
-@subsection Configuration of Solaris kernels
+@node Configuration of Windows
+@subsection Configuration of Windows
-This section will contain information on how to configure your Solaris
-kernel to support the universal TUN/TAP device. You need to install
-this driver yourself.
-
-Unfortunately somebody still has to write the text.
+You will need to install the latest TAP-Win32 driver from OpenVPN.
+You can download it from @uref{http://openvpn.sourceforge.net}.
+Using the Network Connections control panel,
+configure the TAP-Win32 network interface in the same way as you would do from the tinc-up script,
+as explained in the rest of the documentation.
@c ==================================================================
-@node Libraries, , Configuring the kernel, Preparations
+@node Libraries
@section Libraries
@cindex requirements
@cindex libraries
-Before you can configure or build tinc, you need to have the OpenSSL
-library installed on your system. If you try to configure tinc without
-having installed it, configure will give you an error message, and stop.
+Before you can configure or build tinc, you need to have the OpenSSL,
+zlib and lzo libraries installed on your system. If you try to configure tinc without
+having them installed, configure will give you an error message, and stop.
@menu
* OpenSSL::
+* zlib::
+* lzo::
@end menu
@c ==================================================================
-@node OpenSSL, , Libraries, Libraries
+@node OpenSSL
@subsection OpenSSL
@cindex OpenSSL
@subsubheading License
@cindex license
+The complete source code of tinc is covered by the GNU GPL version 2.
Since the license under which OpenSSL is distributed is not directly
compatible with the terms of the GNU GPL
-@uref{http://www.openssl.org/support/faq.html#LEGAL2}, therefore we
-include an addition to the GPL (see also the file COPYING.README):
+@uref{http://www.openssl.org/support/faq.html#LEGAL2}, we
+include an exemption to the GPL (see also the file COPYING.README) to allow
+everyone to create a statically or dynamically linked executable:
@quotation
This program is released under the GPL with the additional exemption
all other requirements of the GPL are met.
@end quotation
+Since the LZO library used by tinc is also covered by the GPL,
+we also present the following exemption:
+
+@quotation
+Hereby I grant a special exception to the tinc VPN project
+(http://www.tinc-vpn.org/) to link the LZO library with the OpenSSL library
+(http://www.openssl.org).
+
+Markus F.X.J. Oberhumer
+@end quotation
+
+
+@c ==================================================================
+@node zlib
+@subsection zlib
+
+@cindex zlib
+For the optional compression of UDP packets, tinc uses the functions provided
+by the zlib library.
+
+If this library is not installed, you wil get an error when configuring
+tinc for build. Support for running tinc without having zlib
+installed @emph{may} be added in the future.
+
+You can use your operating system's package manager to install this if
+available. Make sure you install the development AND runtime versions
+of this package.
+
+If you have to install zlib manually, you can get the source code
+from @url{http://www.gzip.org/zlib/}. Instructions on how to configure,
+build and install this package are included within the package. Please
+make sure you build development and runtime libraries (which is the
+default).
+
+
+@c ==================================================================
+@node lzo
+@subsection lzo
+
+@cindex lzo
+Another form of compression is offered using the lzo library.
+
+If this library is not installed, you wil get an error when configuring
+tinc for build. Support for running tinc without having lzo
+installed @emph{may} be added in the future.
+
+You can use your operating system's package manager to install this if
+available. Make sure you install the development AND runtime versions
+of this package.
+
+If you have to install lzo manually, you can get the source code
+from @url{http://www.oberhumer.com/opensource/lzo/}. Instructions on how to configure,
+build and install this package are included within the package. Please
+make sure you build development and runtime libraries (which is the
+default).
+
@c
@c
@c
@c ==================================================================
-@node Installation, Configuration, Preparations, Top
+@node Installation
@chapter Installation
-If you use Redhat or Debian, you may want to install one of the
+If you use Debian, you may want to install one of the
precompiled packages for your system. These packages are equipped with
system startup scripts and sample configurations.
-If you don't run either of these systems, or you want to compile tinc
+If you cannot use one of the precompiled packages, or you want to compile tinc
for yourself, you can use the source. The source is distributed under
the GNU General Public License (GPL). Download the source from the
-@uref{http://tinc.nl.linux.org/download.html, download page}, which has
+@uref{http://www.tinc-vpn.org/download, download page}, which has
the checksums of these files listed; you may wish to check these with
md5sum before continuing.
-tinc comes in a convenient autoconf/automake package, which you can just
+Tinc comes in a convenient autoconf/automake package, which you can just
treat the same as any other package. Which is just untar it, type
-`configure' and then `make'.
+`./configure' and then `make'.
More detailed instructions are in the file @file{INSTALL}, which is
included in the source distribution.
@c ==================================================================
-@node Building and installing tinc, System files, Installation, Installation
+@node Building and installing tinc
@section Building and installing tinc
Detailed instructions on configuring the source, building tinc and installing tinc
you can use the package management tools of that distribution to install tinc.
The documentation that comes along with your distribution will tell you how to do that.
+@menu
+* Darwin (MacOS/X) build environment::
+* Cygwin (Windows) build environment::
+* MinGW (Windows) build environment::
+@end menu
+
+
+@c ==================================================================
+@node Darwin (MacOS/X) build environment
+@subsection Darwin (MacOS/X) build environment
+
+In order to build tinc on Darwin, you need to install the MacOS/X Developer Tools
+from @uref{http://developer.apple.com/tools/macosxtools.html} and
+a recent version of Fink from @uref{http://fink.sourceforge.net/}.
+
+After installation use fink to download and install the following packages:
+autoconf25, automake, dlcompat, m4, openssl, zlib and lzo.
+
+@c ==================================================================
+@node Cygwin (Windows) build environment
+@subsection Cygwin (Windows) build environment
+
+If Cygwin hasn't already been installed, install it directly from
+@uref{http://www.cygwin.com/}.
+
+When tinc is compiled in a Cygwin environment, it can only be run in this environment,
+but all programs, including those started outside the Cygwin environment, will be able to use the VPN.
+It will also support all features.
+
+@c ==================================================================
+@node MinGW (Windows) build environment
+@subsection MinGW (Windows) build environment
+
+You will need to install the MinGW environment from @uref{http://www.mingw.org}.
+
+When tinc is compiled using MinGW it runs natively under Windows,
+it is not necessary to keep MinGW installed.
+
+When detaching, tinc will install itself as a service,
+which will be restarted automatically after reboots.
+
@c ==================================================================
-@node System files, , Building and installing tinc, Installation
+@node System files
@section System files
Before you can run tinc, you must make sure you have all the needed
@c ==================================================================
-@node Device files, Other files, System files, System files
+@node Device files
@subsection Device files
@cindex device files
-First, you'll need the special device file(s) that form the interface
-between the kernel and the daemon.
-
-The permissions for these files have to be such that only the super user
-may read/write to this file. You'd want this, because otherwise
-eavesdropping would become a bit too easy. This does, however, imply
-that you'd have to run tincd as root.
-
-If you use Linux and have a kernel version prior to 2.4.0, you have to make the
-ethertap devices:
-
-@example
-mknod -m 600 /dev/tap0 c 36 16
-chown 0.0 /dev/tap0
-@end example
-
-Any further ethertap devices have minor device number 16 through 31.
+Most operating systems nowadays come with the necessary device files by default,
+or they have a mechanism to create them on demand.
-If you use the universal TUN/TAP driver, you have to create the
-following device files (unless they already exist):
+If you use Linux and do not have udev installed,
+you may need to create the following device file if it does not exist:
@example
-mknod -m 600 /dev/tun c 10 200
-chown 0.0 /dev/tun
+mknod -m 600 /dev/net/tun c 10 200
@end example
-If you use Linux, and you run the new 2.4 kernel using the devfs filesystem,
-then the TUN/TAP device will probably be automatically generated as
-@file{/dev/net/tun}.
-
@c ==================================================================
-@node Other files, , Device files, System files
+@node Other files
@subsection Other files
@subsubheading @file{/etc/networks}
@example
tinc 655/tcp TINC
tinc 655/udp TINC
-# Ivo Timmermans <itimmermans@@bigfoot.com>
+# Ivo Timmermans <ivo@@tinc-vpn.org>
@end example
@c ==================================================================
-@node Configuration, Running tinc, Installation, Top
+@node Configuration
@chapter Configuration
@menu
@end menu
@c ==================================================================
-@node Configuration introduction, Multiple networks, Configuration, Configuration
+@node Configuration introduction
@section Configuration introduction
-@cindex Network Administrators Guide
Before actually starting to configure tinc and editing files,
make sure you have read this entire section so you know what to expect.
Then, make it clear to yourself how you want to organize your VPN:
What is the network mask of the entire VPN?
Do you need special firewall rules?
Do you have to set up masquerading or forwarding rules?
+Do you want to run tinc in router mode or switch mode?
These questions can only be answered by yourself,
you will not find the answers in this documentation.
Make sure you have an adequate understanding of networks in general.
+@cindex Network Administrators Guide
A good resource on networking is the
@uref{http://www.linuxdoc.org/LDP/nag2/, Linux Network Administrators Guide}.
If you have everything clearly pictured in your mind,
proceed in the following order:
-First, generate the configuration files (tinc.conf, your host configuration file, tinc-up and perhaps tinc-down).
+First, generate the configuration files (@file{tinc.conf}, your host configuration file, @file{tinc-up} and perhaps @file{tinc-down}).
Then generate the keypairs.
Finally, distribute the host configuration files.
These steps are described in the subsections below.
@c ==================================================================
-@node Multiple networks, How connections work, Configuration introduction, Configuration
+@node Multiple networks
@section Multiple networks
@cindex multiple networks
@cindex netname
In order to allow you to run more than one tinc daemon on one computer,
for instance if your computer is part of more than one VPN,
-you can assign a ``netname'' to your VPN.
+you can assign a @var{netname} to your VPN.
It is not required if you only run one tinc daemon,
it doesn't even have to be the same on all the sites of your VPN,
but it is recommended that you choose one anyway.
which will assign a netname to this daemon.
The effect of this is that the daemon will set its configuration
-``root'' to /etc/tinc/netname/, where netname is your argument to the -n
-option. You'll notice that it appears in syslog as ``tinc.netname''.
+root to @file{@value{sysconfdir}/tinc/@var{netname}/}, where @var{netname} is your argument to the -n
+option. You'll notice that it appears in syslog as @file{tinc.@var{netname}}.
However, it is not strictly necessary that you call tinc with the -n
option. In this case, the network name would just be empty, and it will
-be used as such. tinc now looks for files in /etc/tinc/, instead of
-/etc/tinc/netname/; the configuration file should be /etc/tinc/tinc.conf,
-and the host configuration files are now expected to be in /etc/tinc/hosts/.
+be used as such. tinc now looks for files in @file{@value{sysconfdir}/tinc/}, instead of
+@file{@value{sysconfdir}/tinc/@var{netname}/}; the configuration file should be @file{@value{sysconfdir}/tinc/tinc.conf},
+and the host configuration files are now expected to be in @file{@value{sysconfdir}/tinc/hosts/}.
But it is highly recommended that you use this feature of tinc, because
it will be so much clearer whom your daemon talks to. Hence, we will
@c ==================================================================
-@node How connections work, Configuration files, Multiple networks, Configuration
+@node How connections work
@section How connections work
When tinc starts up, it parses the command-line options and then
-reads in the configuration file.
-If it sees a `ConnectTo' value pointing to another tinc daemon in the file,
-it will try to connect to that other one.
+reads in the configuration file tinc.conf.
+If it sees one or more `ConnectTo' values pointing to other tinc daemons in that file,
+it will try to connect to those other daemons.
Whether this succeeds or not and whether `ConnectTo' is specified or not,
tinc will listen for incoming connection from other deamons.
If you did specify a `ConnectTo' value and the other side is not responding,
This means that once started, tinc will stay running until you tell it to stop,
and failures to connect to other tinc daemons will not stop your tinc daemon
for trying again later.
-This means you don't have to intervene if there are any network problems.
+This means you don't have to intervene if there are temporary network problems.
@cindex client
@cindex server
There is no real distinction between a server and a client in tinc.
If you wish, you can view a tinc daemon without a `ConnectTo' value as a server,
and one which does specify such a value as a client.
-It does not matter if two tinc daemons have a `ConnectTo' value pointing to eachother however.
+It does not matter if two tinc daemons have a `ConnectTo' value pointing to each other however.
@c ==================================================================
-@node Configuration files, Generating keypairs, How connections work, Configuration
+@node Configuration files
@section Configuration files
The actual configuration of the daemon is done in the file
-@file{/etc/tinc/netname/tinc.conf} and at least one other file in the directory
-@file{/etc/tinc/netname/hosts/}.
+@file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf} and at least one other file in the directory
+@file{@value{sysconfdir}/tinc/@var{netname}/hosts/}.
These file consists of comments (lines started with a #) or assignments
in the form of
out, remember to replace it with at least one space character.
In this section all valid variables are listed in alphabetical order.
-The default value is given between parentheses; required directives are
-given in @strong{bold}.
+The default value is given between parentheses,
+other comments are between square brackets.
@menu
* Main configuration variables::
* Host configuration variables::
+* Scripts::
* How to configure::
@end menu
@c ==================================================================
-@node Main configuration variables, Host configuration variables, Configuration files, Configuration files
+@node Main configuration variables
@subsection Main configuration variables
@table @asis
-@item @strong{ConnectTo = <name>}
+@cindex AddressFamily
+@item AddressFamily = <ipv4|ipv6|any> (any)
+This option affects the address family of listening and outgoing sockets.
+If any is selected, then depending on the operating system
+both IPv4 and IPv6 or just IPv6 listening sockets will be created.
+
+@cindex BindToAddress
+@item BindToAddress = <@var{address}> [experimental]
+If your computer has more than one IPv4 or IPv6 address, tinc
+will by default listen on all of them for incoming connections.
+It is possible to bind only to a single address with this variable.
+
+This option may not work on all platforms.
+
+@cindex BindToInterface
+@item BindToInterface = <@var{interface}> [experimental]
+If you have more than one network interface in your computer, tinc will
+by default listen on all of them for incoming connections. It is
+possible to bind tinc to a single interface like eth0 or ppp0 with this
+variable.
+
+This option may not work on all platforms.
+
@cindex ConnectTo
-Specifies which host to connect to on startup. Multiple ConnectTo
-variables may be specified, if connecting to the first one fails then
-tinc will try the next one, and so on. It is possible to specify
-hostnames for dynamic IP addresses (like those given on dyndns.org),
-tinc will not cache the resolved IP address.
+@item ConnectTo = <@var{name}>
+Specifies which other tinc daemon to connect to on startup.
+Multiple ConnectTo variables may be specified,
+in which case outgoing connections to each specified tinc daemon are made.
+The names should be known to this tinc daemon
+(i.e., there should be a host configuration file for the name on the ConnectTo line).
+
+If you don't specify a host with ConnectTo,
+tinc won't try to connect to other daemons at all,
+and will instead just listen for incoming connections.
+
+@cindex Device
+@item Device = <@var{device}> (@file{/dev/tap0}, @file{/dev/net/tun} or other depending on platform)
+The virtual network device to use.
+Tinc will automatically detect what kind of device it is.
+Note that you can only use one device per daemon.
+Under Windows, use @var{Interface} instead of @var{Device}.
+Note that you can only use one device per daemon.
+See also @ref{Device files}.
+
+@cindex DeviceType
+@item DeviceType = <tun|tunnohead|tunifhead|tap> (only supported on BSD platforms)
+The type of the virtual network device.
+Tinc will normally automatically select the right type, and this option should not be used.
+However, in case tinc does not seem to correctly interpret packets received from the virtual network device,
+using this option might help.
-If you don't specify a host with ConnectTo, regardless of whether a
-value for ConnectPort is given, tinc won't connect at all, and will
-instead just listen for incoming connections.
+@table @asis
+@item tun
+Set type to tun.
+Depending on the platform, this can either be with or without an address family header (see below).
+
+@cindex tunnohead
+@item tunnohead
+Set type to tun without an address family header.
+Tinc will expect packets read from the virtual network device to start with an IP header.
+On some platforms IPv6 packets cannot be read from or written to the device in this mode.
+
+@cindex tunifhead
+@item tunifhead
+Set type to tun with an address family header.
+Tinc will expect packets read from the virtual network device
+to start with a four byte header containing the address family,
+followed by an IP header.
+This mode should support both IPv4 and IPv6 packets.
+
+@item tap
+Set type to tap.
+Tinc will expect packets read from the virtual network device
+to start with an Ethernet header.
+@end table
+
+@cindex GraphDumpFile
+@item GraphDumpFile = <@var{filename}> [experimental]
+If this option is present,
+tinc will dump the current network graph to the file @var{filename}
+every minute, unless there were no changes to the graph.
+The file is in a format that can be read by graphviz tools.
+If @var{filename} starts with a pipe symbol |,
+then the rest of the filename is interpreted as a shell command
+that is executed, the graph is then sent to stdin.
-@item Hostnames = <yes|no> (no)
@cindex Hostnames
+@item Hostnames = <yes|no> (no)
This option selects whether IP addresses (both real and on the VPN)
should be resolved. Since DNS lookups are blocking, it might affect
tinc's efficiency, even stopping the daemon for a few seconds everytime
This does not affect resolving hostnames to IP addresses from the
configuration file.
-@item Interface = <device>
@cindex Interface
-If you have more than one network interface in your computer, tinc will
-by default listen on all of them for incoming connections. It is
-possible to bind tinc to a single interface like eth0 or ppp0 with this
-variable.
+@item Interface = <@var{interface}>
+Defines the name of the interface corresponding to the virtual network device.
+Depending on the operating system and the type of device this may or may not actually set the name of the interface.
+Under Windows, this variable is used to select which network interface will be used.
+If you specified a Device, this variable is almost always already correctly set.
+
+@cindex Mode
+@item Mode = <router|switch|hub> (router)
+This option selects the way packets are routed to other daemons.
-@item InterfaceIP = <local address>
-@cindex InterfaceIP
-If your computer has more than one IP address on a single interface (for
-example if you are running virtual hosts), tinc will by default listen
-on all of them for incoming connections. It is possible to bind tinc to
-a single IP address with this variable. It is still possible to listen
-on several interfaces at the same time though, if they share the same IP
-address.
+@table @asis
+@cindex router
+@item router
+In this mode Subnet
+variables in the host configuration files will be used to form a routing table.
+Only unicast packets of routable protocols (IPv4 and IPv6) are supported in this mode.
+
+This is the default mode, and unless you really know you need another mode, don't change it.
+
+@cindex switch
+@item switch
+In this mode the MAC addresses of the packets on the VPN will be used to
+dynamically create a routing table just like an Ethernet switch does.
+Unicast, multicast and broadcast packets of every protocol that runs over Ethernet are supported in this mode
+at the cost of frequent broadcast ARP requests and routing table updates.
+
+This mode is primarily useful if you want to bridge Ethernet segments.
+
+@cindex hub
+@item hub
+This mode is almost the same as the switch mode, but instead
+every packet will be broadcast to the other daemons
+while no routing table is managed.
+@end table
-@item KeyExpire = <seconds> (3600)
@cindex KeyExpire
+@item KeyExpire = <@var{seconds}> (3600)
This option controls the time the encryption keys used to encrypt the data
are valid. It is common practice to change keys at regular intervals to
make it even harder for crackers, even though it is thought to be nearly
impossible to crack a single key.
-@item ListenPort = <port> (655)
-@cindex ListenPort
-Listen on local port port. The computer connecting to this daemon should
-use this number as the argument for his ConnectPort.
+@cindex MACExpire
+@item MACExpire = <@var{seconds}> (600)
+This option controls the amount of time MAC addresses are kept before they are removed.
+This only has effect when Mode is set to "switch".
-@item @strong{Name = <name>}
@cindex Name
-This is a symbolic name for this connection. It can be anything
+@item Name = <@var{name}> [required]
+This is a symbolic name for this connection.
+The name should consist only of alfanumeric and underscore characters (a-z, A-Z, 0-9 and _).
-@item PingTimeout = <seconds> (5)
-@cindex PingTimeout
+@cindex PingInterval
+@item PingInterval = <@var{seconds}> (60)
The number of seconds of inactivity that tinc will wait before sending a
-probe to the other end. If that other end doesn't answer within that
-same amount of seconds, the connection is terminated, and the others
-will be notified of this.
+probe to the other end.
+
+@cindex PingTimeout
+@item PingTimeout = <@var{seconds}> (5)
+The number of seconds to wait for a response to pings or to allow meta
+connections to block. If the other end doesn't respond within this time,
+the connection is terminated, and the others will be notified of this.
+
+@cindex PriorityInheritance
+@item PriorityInheritance = <yes|no> (no) [experimental]
+When this option is enabled the value of the TOS field of tunneled IPv4 packets
+will be inherited by the UDP packets that are sent out.
-@item PrivateKey = <key> (obsolete)
@cindex PrivateKey
+@item PrivateKey = <@var{key}> [obsolete]
This is the RSA private key for tinc. However, for safety reasons it is
advised to store private keys of any kind in separate files. This prevents
accidental eavesdropping if you are editting the configuration file.
-@item @strong{PrivateKeyFile = <path>} (recommended)
@cindex PrivateKeyFile
+@item PrivateKeyFile = <@var{path}> (@file{@value{sysconfdir}/tinc/@var{netname}/rsa_key.priv})
This is the full path name of the RSA private key file that was
-generated by ``tincd --generate-keys''. It must be a full path, not a
+generated by @samp{tincd --generate-keys}. It must be a full path, not a
relative directory.
-@item @strong{TapDevice = <device>} (/dev/tap0)
-@cindex TapDevice
-The ethertap device to use. Note that you can only use one device per
-daemon. The info pages of the tinc package contain more information
-about configuring an ethertap device for Linux.
+Note that there must be exactly one of PrivateKey
+or PrivateKeyFile
+specified in the configuration file.
+
+@cindex ProcessPriority
+@item ProcessPriority = <low|normal|high>
+When this option is used the priority of the tincd process will be adjusted.
+Increasing the priority may help to reduce latency and packet loss on the VPN.
+
+@cindex TunnelServer
+@item TunnelServer = <yes|no> (no) [experimental]
+When this option is enabled tinc will no longer forward information between other tinc daemons,
+and will only allow nodes and subnets on the VPN which are present in the
+@file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
-@item TCPonly = <yes|no> (no, experimental)
-@cindex TCPonly
-If this variable is set to yes, then the packets are tunnelled over a TCP
-connection instead of a UDP connection. This is especially useful for those
-who want to run a tinc daemon from behind a masquerading firewall, or if
-UDP packet routing is disabled somehow. This is experimental code,
-try this at your own risk.
@end table
@c ==================================================================
-@node Host configuration variables, How to configure, Main configuration variables, Configuration files
+@node Host configuration variables
@subsection Host configuration variables
@table @asis
-@item @strong{Address = <IP address|hostname>}
@cindex Address
+@item Address = <@var{IP address}|@var{hostname}> [recommended]
This variable is only required if you want to connect to this host. It
must resolve to the external IP address where the host can be reached,
not the one that is internal to the VPN.
-@item IndirectData = <yes|no> (no, experimental)
+@cindex Cipher
+@item Cipher = <@var{cipher}> (blowfish)
+The symmetric cipher algorithm used to encrypt UDP packets.
+Any cipher supported by OpenSSL is recognized.
+Furthermore, specifying "none" will turn off packet encryption.
+It is best to use only those ciphers which support CBC mode.
+
+@cindex Compression
+@item Compression = <@var{level}> (0)
+This option sets the level of compression used for UDP packets.
+Possible values are 0 (off), 1 (fast zlib) and any integer up to 9 (best zlib),
+10 (fast lzo) and 11 (best lzo).
+
+@cindex Digest
+@item Digest = <@var{digest}> (sha1)
+The digest algorithm used to authenticate UDP packets.
+Any digest supported by OpenSSL is recognized.
+Furthermore, specifying "none" will turn off packet authentication.
+
@cindex IndirectData
+@item IndirectData = <yes|no> (no)
This option specifies whether other tinc daemons besides the one you
specified with ConnectTo can make a direct connection to you. This is
especially useful if you are behind a firewall and it is impossible to
make a connection from the outside to your tinc daemon. Otherwise, it
is best to leave this option out or set it to no.
-@item Port = <port> (655)
+@cindex MACLength
+@item MACLength = <@var{bytes}> (4)
+The length of the message authentication code used to authenticate UDP packets.
+Can be anything from 0
+up to the length of the digest produced by the digest algorithm.
+
+@cindex PMTU
+@item PMTU = <@var{mtu}> (1514)
+This option controls the initial path MTU to this node.
+
+@cindex PMTUDiscovery
+@item PMTUDiscovery = <yes|no> (yes)
+When this option is enabled, tinc will try to discover the path MTU to this node.
+After the path MTU has been discovered, it will be enforced on the VPN.
+
@cindex Port
-Connect to the upstream host (given with the ConnectTo directive) on
-port port. port may be given in decimal (default), octal (when preceded
-by a single zero) o hexadecimal (prefixed with 0x). port is the port
-number for both the UDP and the TCP (meta) connections.
+@item Port = <@var{port}> (655)
+This is the port this tinc daemon listens on.
+You can use decimal portnumbers or symbolic names (as listed in @file{/etc/services}).
-@item PublicKey = <key> (obsolete)
@cindex PublicKey
+@item PublicKey = <@var{key}> [obsolete]
This is the RSA public key for this host.
-@item PublicKeyFile = <path> (obsolete)
@cindex PublicKeyFile
+@item PublicKeyFile = <@var{path}> [obsolete]
This is the full path name of the RSA public key file that was generated
-by ``tincd --generate-keys''. It must be a full path, not a relative
+by @samp{tincd --generate-keys}. It must be a full path, not a relative
directory.
@cindex PEM format
in each host configuration file, if you want to be able to establish a
connection with that host.
-@item Subnet = <IP address/maskbits>
@cindex Subnet
-This is the subnet range of all IP addresses that will be accepted by
-the host that defines it.
-
-The range must be contained in the IP address range of the tap device,
-not the real IP address of the host running tincd.
+@item Subnet = <@var{address}[/@var{prefixlength}[#@var{weight}]]>
+The subnet which this tinc daemon will serve.
+Tinc tries to look up which other daemon it should send a packet to by searching the appropiate subnet.
+If the packet matches a subnet,
+it will be sent to the daemon who has this subnet in his host configuration file.
+Multiple subnet lines can be specified for each daemon.
+
+Subnets can either be single MAC, IPv4 or IPv6 addresses,
+in which case a subnet consisting of only that single address is assumed,
+or they can be a IPv4 or IPv6 network address with a prefixlength.
+Shorthand notations are not supported.
+For example, IPv4 subnets must be in a form like 192.168.1.0/24,
+where 192.168.1.0 is the network address and 24 is the number of bits set in the netmask.
+Note that subnets like 192.168.1.1/24 are invalid!
+Read a networking HOWTO/FAQ/guide if you don't understand this.
+IPv6 subnets are notated like fec0:0:0:1:0:0:0:0/64.
+MAC addresses are notated like 0:1a:2b:3c:4d:5e.
@cindex CIDR notation
-maskbits is the number of bits set to 1 in the netmask part; for
+Prefixlength is the number of bits set to 1 in the netmask part; for
example: netmask 255.255.255.0 would become /24, 255.255.252.0 becomes
/22. This conforms to standard CIDR notation as described in
@uref{ftp://ftp.isi.edu/in-notes/rfc1519.txt, RFC1519}
-@item TCPonly = <yes|no> (no, experimental)
+@cindex Subnet weight
+A Subnet can be given a weight to indicate its priority over identical Subnets
+owned by different nodes. The default weight is 10. Lower values indicate
+higher priority. Packets will be sent to the node with the highest priority,
+unless that node is not reachable, in which case the node with the next highest
+priority will be tried, and so on.
+
@cindex TCPonly
+@item TCPonly = <yes|no> (no) [deprecated]
If this variable is set to yes, then the packets are tunnelled over a
TCP connection instead of a UDP connection. This is especially useful
for those who want to run a tinc daemon from behind a masquerading
-firewall, or if UDP packet routing is disabled somehow. This is
-experimental code, try this at your own risk. It may not work at all.
+firewall, or if UDP packet routing is disabled somehow.
+Setting this options also implicitly sets IndirectData.
+
+Since version 1.0.10, tinc will automatically detect whether communication via
+UDP is possible or not.
@end table
@c ==================================================================
-@node How to configure, , Host configuration variables, Configuration files
+@node Scripts
+@subsection Scripts
+
+@cindex scripts
+Apart from reading the server and host configuration files,
+tinc can also run scripts at certain moments.
+Under Windows (not Cygwin), the scripts should have the extension .bat.
+
+@table @file
+@cindex tinc-up
+@item @value{sysconfdir}/tinc/@var{netname}/tinc-up
+This is the most important script.
+If it is present it will be executed right after the tinc daemon has been
+started and has connected to the virtual network device.
+It should be used to set up the corresponding network interface,
+but can also be used to start other things.
+Under Windows you can use the Network Connections control panel instead of creating this script.
+
+@cindex tinc-down
+@item @value{sysconfdir}/tinc/@var{netname}/tinc-down
+This script is started right before the tinc daemon quits.
+
+@item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-up
+This script is started when the tinc daemon with name @var{host} becomes reachable.
+
+@item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-down
+This script is started when the tinc daemon with name @var{host} becomes unreachable.
+
+@item @value{sysconfdir}/tinc/@var{netname}/host-up
+This script is started when any host becomes reachable.
+
+@item @value{sysconfdir}/tinc/@var{netname}/host-down
+This script is started when any host becomes unreachable.
+
+@item @value{sysconfdir}/tinc/@var{netname}/subnet-up
+This script is started when a Subnet becomes reachable.
+The Subnet and the node it belongs to are passed in environment variables.
+
+@item @value{sysconfdir}/tinc/@var{netname}/subnet-down
+This script is started when a Subnet becomes unreachable.
+@end table
+
+@cindex environment variables
+The scripts are started without command line arguments,
+but can make use of certain environment variables.
+Under UNIX like operating systems the names of environment variables must be preceded by a $ in scripts.
+Under Windows, in @file{.bat} files, they have to be put between % signs.
+
+@table @env
+@cindex NETNAME
+@item NETNAME
+If a netname was specified, this environment variable contains it.
+
+@cindex NAME
+@item NAME
+Contains the name of this tinc daemon.
+
+@cindex DEVICE
+@item DEVICE
+Contains the name of the virtual network device that tinc uses.
+
+@cindex INTERFACE
+@item INTERFACE
+Contains the name of the virtual network interface that tinc uses.
+This should be used for commands like ifconfig.
+
+@cindex NODE
+@item NODE
+When a host becomes (un)reachable, this is set to its name.
+If a subnet becomes (un)reachable, this is set to the owner of that subnet.
+
+@cindex REMOTEADDRESS
+@item REMOTEADDRESS
+When a host becomes (un)reachable, this is set to its real address.
+
+@cindex REMOTEPORT
+@item REMOTEPORT
+When a host becomes (un)reachable,
+this is set to the port number it uses for communication with other tinc daemons.
+
+@cindex SUBNET
+@item SUBNET
+When a subnet becomes (un)reachable, this is set to the subnet.
+
+@cindex WEIGHT
+@item SUBNET
+When a subnet becomes (un)reachable, this is set to the subnet weight.
+
+@end table
+
+
+@c ==================================================================
+@node How to configure
@subsection How to configure
@subsubheading Step 1. Creating the main configuration file
-The main configuration file will be called @file{/etc/tinc/netname/tinc.conf}.
+The main configuration file will be called @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf}.
Adapt the following example to create a basic configuration file:
@example
-Name = @emph{yourname}
-TapDevice = @emph{/dev/tap0}
-PrivateKeyFile = /etc/tinc/@emph{netname}/rsa_key.priv
+Name = @var{yourname}
+Device = @file{/dev/tap0}
@end example
Then, if you know to which other tinc daemon(s) yours is going to connect,
@subsubheading Step 2. Creating your host configuration file
If you added a line containing `Name = yourname' in the main configuarion file,
-you will need to create a host configuration file @file{/etc/tinc/netname/hosts/yourname}.
+you will need to create a host configuration file @file{@value{sysconfdir}/tinc/@var{netname}/hosts/yourname}.
Adapt the following example to create a host configuration file:
@example
-Address = @emph{your.real.hostname.org}
-Subnet = @emph{192.168.1.0/24}
+Address = your.real.hostname.org
+Subnet = 192.168.1.0/24
@end example
You can also use an IP address instead of a hostname.
@c ==================================================================
-@node Generating keypairs, Network interfaces, Configuration files, Configuration
+@node Generating keypairs
@section Generating keypairs
@cindex key generation
you can easily create a public/private keypair by entering the following command:
@example
-tincd -n @emph{netname} -K
+tincd -n @var{netname} -K
@end example
-tinc will generate a public and a private key and ask you where to put them.
+Tinc will generate a public and a private key and ask you where to put them.
Just press enter to accept the defaults.
@c ==================================================================
-@node Network interfaces, Example configuration, Generating keypairs, Configuration
+@node Network interfaces
@section Network interfaces
Before tinc can start transmitting data over the tunnel, it must
-set up the ethertap network devices.
+set up the virtual network interface.
First, decide which IP addresses you want to have associated with these
devices, and what network mask they must have.
-tinc will open an ethertap device or TUN/TAP device, which will also
-create a network interface called `tap0', or `tap1', and so on if you are using
-the ethertap driver, or a network interface with the same name as netname
-if you are using the universal TUN/TAP driver.
+Tinc will open a virtual network device (@file{/dev/tun}, @file{/dev/tap0} or similar),
+which will also create a network interface called something like @samp{tun0}, @samp{tap0}.
+If you are using the Linux tun/tap driver, the network interface will by default have the same name as the @var{netname}.
+Under Windows you can change the name of the network interface from the Network Connections control panel.
@cindex tinc-up
-You can configure that device by putting ordinary ifconfig, route, and other commands
-to a script named @file{/etc/tinc/netname/tinc-up}. When tinc starts, this script
-will be executed. When tinc exits, it will execute the script named
-@file{/etc/tinc/netname/tinc-down}, but normally you don't need to create that script.
+You can configure the network interface by putting ordinary ifconfig, route, and other commands
+to a script named @file{@value{sysconfdir}/tinc/@var{netname}/tinc-up}.
+When tinc starts, this script will be executed. When tinc exits, it will execute the script named
+@file{@value{sysconfdir}/tinc/@var{netname}/tinc-down}, but normally you don't need to create that script.
-An example @file{tinc-up} script when using the TUN/TAP driver:
+An example @file{tinc-up} script:
@example
#!/bin/sh
-ifconfig $NETNAME hw ether fe:fd:00:00:00:00
-ifconfig $NETNAME @emph{xx}.@emph{xx}.@emph{xx}.@emph{xx} netmask @emph{mask}
-ifconfig $NETNAME -arp
+ifconfig $INTERFACE 192.168.1.1 netmask 255.255.0.0
@end example
-@cindex MAC address
-@cindex hardware address
-The first line sets up the MAC address of the network interface.
-Due to the nature of how Ethernet and tinc work, it has to be set to fe:fd:00:00:00:00.
-(tinc versions prior to 1.0pre3 required that the MAC address matched the IP address.)
-You can use the environment variable $NETNAME to get the name of the interface.
-If you are using the ethertap driver however, you need to replace it with tap@emph{N},
-corresponding to the device file name.
-
-@cindex ifconfig
-The next line gives the interface an IP address and a netmask.
+This script gives the interface an IP address and a netmask.
The kernel will also automatically add a route to this interface, so normally you don't need
to add route commands to the @file{tinc-up} script.
The kernel will also bring the interface up after this command.
The netmask is the mask of the @emph{entire} VPN network, not just your
own subnet.
-@cindex arp
-The last line tells the kernel not to use ARP on that interface.
-Again this has to do with how Ethernet and tinc work. Don't forget to add this line.
+The exact syntax of the ifconfig and route commands differs from platform to platform.
+You can look up the commands for setting addresses and adding routes in @ref{Platform specific information},
+but it is best to consult the manpages of those utilities on your platform.
@c ==================================================================
-@node Example configuration, , Network interfaces, Configuration
+@node Example configuration
@section Example configuration
D: net 10.4.0.0 mask 255.255.0.0 gateway 10.4.3.32 internet IP 4.5.6.7
@end example
-``gateway'' is the VPN IP address of the machine that is running the
-tincd. ``internet IP'' is the IP address of the firewall, which does not
-need to run tincd, but it must do a port forwarding of TCP&UDP on port
+Here, ``gateway'' is the VPN IP address of the machine that is running the
+tincd, and ``internet IP'' is the IP address of the firewall, which does not
+need to run tincd, but it must do a port forwarding of TCP and UDP on port
655 (unless otherwise configured).
In this example, it is assumed that eth0 is the interface that points to
@emph{BranchA} would be configured like this:
-In @file{/etc/tinc/company/tinc-up}:
+In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
# Real interface of internal network:
-# ifconfig eth0 10.1.54.1 netmask 255.255.0.0 broadcast 10.1.255.255
+# ifconfig eth0 10.1.54.1 netmask 255.255.0.0
-ifconfig tap0 hw ether fe:fd:00:00:00:00
-ifconfig tap0 10.1.54.1 netmask 255.0.0.0
-ifconfig tap0 -arp
+ifconfig $INTERFACE 10.1.54.1 netmask 255.0.0.0
@end example
-and in @file{/etc/tinc/company/tinc.conf}:
+and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
@example
Name = BranchA
-PrivateKey = /etc/tinc/company/rsa_key.priv
-TapDevice = /dev/tap0
+Device = /dev/tap0
@end example
-On all hosts, /etc/tinc/company/hosts/BranchA contains:
+On all hosts, @file{@value{sysconfdir}/tinc/company/hosts/BranchA} contains:
@example
Subnet = 10.1.0.0/16
Address = 1.2.3.4
-Note that the IP addresses of eth0 and tap0 are the same.
-This is quite possible, if you make sure that the netmasks of the interfaces are different.
-It is in fact recommended to give give both real internal network interfaces and tap interfaces the same IP address,
-since that will make things a lot easier to remember and set up.
-
-----BEGIN RSA PUBLIC KEY-----
...
-----END RSA PUBLIC KEY-----
@end example
+Note that the IP addresses of eth0 and tap0 are the same.
+This is quite possible, if you make sure that the netmasks of the interfaces are different.
+It is in fact recommended to give give both real internal network interfaces and tap interfaces the same IP address,
+since that will make things a lot easier to remember and set up.
+
@subsubheading For Branch B
-In @file{/etc/tinc/company/tinc-up}:
+In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
# Real interface of internal network:
-# ifconfig eth0 10.2.43.8 netmask 255.255.0.0 broadcast 10.2.255.255
+# ifconfig eth0 10.2.43.8 netmask 255.255.0.0
-ifconfig tap0 hw ether fe:fd:00:00:00:00
-ifconfig tap0 10.2.1.12 netmask 255.0.0.0
-ifconfig tap0 -arp
+ifconfig $INTERFACE 10.2.1.12 netmask 255.0.0.0
@end example
-and in @file{/etc/tinc/company/tinc.conf}:
+and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
@example
Name = BranchB
ConnectTo = BranchA
-PrivateKey = /etc/tinc/company/rsa_key.priv
@end example
Note here that the internal address (on eth0) doesn't have to be the
same as on the tap0 device. Also, ConnectTo is given so that no-one can
connect to this node.
-On all hosts, in @file{/etc/tinc/company/hosts/BranchB}:
+On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchB}:
@example
Subnet = 10.2.0.0/16
@subsubheading For Branch C
-In @file{/etc/tinc/company/tinc-up}:
+In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
# Real interface of internal network:
-# ifconfig eth0 10.3.69.254 netmask 255.255.0.0 broadcast 10.3.255.255
+# ifconfig eth0 10.3.69.254 netmask 255.255.0.0
-ifconfig tap1 hw ether fe:fd:00:00:00:00
-ifconfig tap1 10.3.69.254 netmask 255.0.0.0
-ifconfig tap1 -arp
+ifconfig $INTERFACE 10.3.69.254 netmask 255.0.0.0
@end example
-and in @file{/etc/tinc/company/tinc.conf}:
+and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
@example
Name = BranchC
ConnectTo = BranchA
-TapDevice = /dev/tap1
+Device = /dev/tap1
@end example
C already has another daemon that runs on port 655, so they have to
reserve another port for tinc. It knows the portnumber it has to listen on
from it's own host configuration file.
-On all hosts, in @file{/etc/tinc/company/hosts/BranchC}:
+On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchC}:
@example
Address = 3.4.5.6
@subsubheading For Branch D
-In @file{/etc/tinc/company/tinc-up}:
+In @file{@value{sysconfdir}/tinc/company/tinc-up}:
@example
# Real interface of internal network:
-# ifconfig eth0 10.4.3.32 netmask 255.255.0.0 broadcast 10.4.255.255
+# ifconfig eth0 10.4.3.32 netmask 255.255.0.0
-ifconfig company hw ether fe:fd:0a:04:03:20
-ifconfig company 10.4.3.32 netmask 255.0.0.0
-ifconfig company -arp
+ifconfig $INTERFACE 10.4.3.32 netmask 255.0.0.0
@end example
-and in @file{/etc/tinc/company/tinc.conf}:
+and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
@example
Name = BranchD
ConnectTo = BranchC
-TapDevice = /dev/net/tun
-PrivateKeyFile = /etc/tinc/company/rsa_key.priv
+Device = /dev/net/tun
@end example
D will be connecting to C, which has a tincd running for this network on
port 2000. It knows the port number from the host configuration file.
-Also note that since D uses the TUN/TAP driver, the network interface
+Also note that since D uses the tun/tap driver, the network interface
will not be called `tun' or `tap0' or something like that, but will
have the same name as netname.
-On all hosts, in @file{/etc/tinc/company/hosts/BranchD}:
+On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchD}:
@example
Subnet = 10.4.0.0/16
tincd -n company -K
@end example
-The private key is stored in @file{/etc/tinc/company/rsa_key.priv},
-the public key is put into the host configuration file in the @file{/etc/tinc/company/hosts/} directory.
+The private key is stored in @file{@value{sysconfdir}/tinc/company/rsa_key.priv},
+the public key is put into the host configuration file in the @file{@value{sysconfdir}/tinc/company/hosts/} directory.
During key generation, tinc automatically guesses the right filenames based on the -n option and
the Name directive in the @file{tinc.conf} file (if it is available).
@c ==================================================================
-@node Running tinc, Technical information, Configuration, Top
+@node Running tinc
@chapter Running tinc
If everything else is done, you can start tinc by typing the following command:
@example
-tincd -n @emph{netname}
+tincd -n @var{netname}
@end example
@cindex daemon
-tinc will detach from the terminal and continue to run in the background like a good daemon.
+Tinc will detach from the terminal and continue to run in the background like a good daemon.
If there are any problems however you can try to increase the debug level
and look in the syslog to find out what the problems are.
@menu
* Runtime options::
+* Signals::
+* Debug levels::
+* Solving problems::
* Error messages::
+* Sending bug reports::
@end menu
@c ==================================================================
-@node Runtime options, Error messages, , Running tinc
+@node Runtime options
@section Runtime options
Besides the settings in the configuration file, tinc also accepts some
command line options.
-This list is a longer version of that in the manpage. The latter is
-generated automatically, so may be more up-to-date.
-
@cindex command line
@cindex runtime options
@cindex options
@c from the manpage
-@table @samp
-@item -c, --config=PATH
-Read configuration options from the directory PATH. The default is
-@file{/etc/tinc/netname/}.
+@table @option
+@item -c, --config=@var{path}
+Read configuration options from the directory @var{path}. The default is
+@file{@value{sysconfdir}/tinc/@var{netname}/}.
+
+@item -D, --no-detach
+Don't fork and detach.
+This will also disable the automatic restart mechanism for fatal errors.
@cindex debug level
-@item -d
-Increase debug level. The higher it gets, the more gets
+@item -d, --debug=@var{level}
+Set debug level to @var{level}. The higher the debug level, the more gets
logged. Everything goes via syslog.
-0 is the default, only some basic information connection attempts get
-logged. Setting it to 1 will log a bit more, still not very
-disturbing. With two -d's tincd will log protocol information, which can
-get pretty noisy. Three or more -d's will output every single packet
-that goes out or comes in, which probably generates more data than the
-packets themselves.
-
-@item -k, --kill
-Attempt to kill a running tincd and exit. A TERM signal (15) gets sent
-to the daemon that his its PID in /var/run/tinc.pid.
+@item -k, --kill[=@var{signal}]
+Attempt to kill a running tincd (optionally with the specified @var{signal} instead of SIGTERM) and exit.
+Use it in conjunction with the -n option to make sure you kill the right tinc daemon.
+Under native Windows the optional argument is ignored,
+the service will always be stopped and removed.
-Because it kills only one tinc daemon, you should use -n here if you
-started it that way. It will then read the PID from
-@file{/var/run/tinc.NETNAME.pid}.
+@item -n, --net=@var{netname}
+Use configuration for net @var{netname}. @xref{Multiple networks}.
-@item -n, --net=NETNAME
-Connect to net NETNAME. @xref{Multiple networks}.
-
-@item -K, --generate-keys[=BITS]
-Generate public/private keypair of BITS length. If BITS is not specified,
-1024 is the default. tinc will ask where you want to store the files,
+@item -K, --generate-keys[=@var{bits}]
+Generate public/private keypair of @var{bits} length. If @var{bits} is not specified,
+2048 is the default. tinc will ask where you want to store the files,
but will default to the configuration directory (you can use the -c or -n option
in combination with -K). After that, tinc will quit.
+@item -L, --mlock
+Lock tinc into main memory.
+This will prevent sensitive data like shared private keys to be written to the system swap files/partitions.
+
+@item --logfile[=@var{file}]
+Write log entries to a file instead of to the system logging facility.
+If @var{file} is omitted, the default is @file{@value{localstatedir}/log/tinc.@var{netname}.log}.
+
+@item --pidfile=@var{file}
+Write PID to @var{file} instead of @file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
+
+@item --bypass-security
+Disables encryption and authentication.
+Only useful for debugging.
+
+@item -R, --chroot
+Change process root directory to the directory where the config file is
+located (@file{@value{sysconfdir}/tinc/@var{netname}/} as determined by
+-n/--net option or as given by -c/--config option), for added security.
+The chroot is performed after all the initialization is done, after
+writing pid files and opening network sockets.
+
+Note that this option alone does not do any good without -U/--user, below.
+
+Note also that tinc can't run scripts anymore (such as tinc-down or host-up),
+unless it's setup to be runnable inside chroot environment.
+
+@item -U, --user=@var{user}
+Switch to the given @var{user} after initialization, at the same time as
+chroot is performed (see --chroot above). With this option tinc drops
+privileges, for added security.
+
@item --help
Display a short reminder of these runtime options and terminate.
@end table
+@c ==================================================================
+@node Signals
+@section Signals
+
+@cindex signals
+You can also send the following signals to a running tincd process:
+
+@c from the manpage
+@table @samp
+
+@item ALRM
+Forces tinc to try to connect to all uplinks immediately.
+Usually tinc attempts to do this itself,
+but increases the time it waits between the attempts each time it failed,
+and if tinc didn't succeed to connect to an uplink the first time after it started,
+it defaults to the maximum time of 15 minutes.
+
+@item HUP
+Partially rereads configuration files.
+Connections to hosts whose host config file are removed are closed.
+New outgoing connections specified in @file{tinc.conf} will be made.
+
+@item INT
+Temporarily increases debug level to 5.
+Send this signal again to revert to the original level.
+
+@item USR1
+Dumps the connection list to syslog.
+
+@item USR2
+Dumps virtual network device statistics, all known nodes, edges and subnets to syslog.
+
+@item WINCH
+Purges all information remembered about unreachable nodes.
+
+@end table
+
+@c ==================================================================
+@node Debug levels
+@section Debug levels
+
+@cindex debug levels
+The tinc daemon can send a lot of messages to the syslog.
+The higher the debug level, the more messages it will log.
+Each level inherits all messages of the previous level:
+
+@c from the manpage
+@table @samp
+
+@item 0
+This will log a message indicating tinc has started along with a version number.
+It will also log any serious error.
+
+@item 1
+This will log all connections that are made with other tinc daemons.
+
+@item 2
+This will log status and error messages from scripts and other tinc daemons.
+
+@item 3
+This will log all requests that are exchanged with other tinc daemons. These include
+authentication, key exchange and connection list updates.
+
+@item 4
+This will log a copy of everything received on the meta socket.
+
+@item 5
+This will log all network traffic over the virtual private network.
+
+@end table
+
+@c ==================================================================
+@node Solving problems
+@section Solving problems
+
+If tinc starts without problems, but if the VPN doesn't work, you will have to find the cause of the problem.
+The first thing to do is to start tinc with a high debug level in the foreground,
+so you can directly see everything tinc logs:
+
+@example
+tincd -n @var{netname} -d5 -D
+@end example
+
+If tinc does not log any error messages, then you might want to check the following things:
+
+@itemize
+@item @file{tinc-up} script
+Does this script contain the right commands?
+Normally you must give the interface the address of this host on the VPN, and the netmask must be big enough so that the entire VPN is covered.
+
+@item Subnet
+Does the Subnet (or Subnets) in the host configuration file of this host match the portion of the VPN that belongs to this host?
+
+@item Firewalls and NATs
+Do you have a firewall or a NAT device (a masquerading firewall or perhaps an ADSL router that performs masquerading)?
+If so, check that it allows TCP and UDP traffic on port 655.
+If it masquerades and the host running tinc is behind it, make sure that it forwards TCP and UDP traffic to port 655 to the host running tinc.
+You can add @samp{TCPOnly = yes} to your host config file to force tinc to only use a single TCP connection,
+this works through most firewalls and NATs. Since version 1.0.10, tinc will automatically fall back to TCP if direct communication via UDP is not possible.
+
+@end itemize
+
@c ==================================================================
-@node Error messages, , Runtime options, Running tinc
+@node Error messages
@section Error messages
-What follows is a list of the most common error messages you can see
-when configuring tinc. Most of these messages are visible in the syslog
-only, so keep an eye on it!
+What follows is a list of the most common error messages you might find in the logs.
+Some of them will only be visible if the debug level is high enough.
-@table @strong
+@table @samp
@item Could not open /dev/tap0: No such device
@itemize
@itemize
@item You forgot to `modprobe tun'.
@item You forgot to compile `Universal TUN/TAP driver' in the kernel.
+@item The tun device is located somewhere else in @file{/dev/}.
+@end itemize
+
+@item Network address and prefix length do not match!
+
+@itemize
+@item The Subnet field must contain a @emph{network} address, trailing bits should be 0.
+@item If you only want to use one IP address, set the netmask to /32.
+@end itemize
+
+@item Error reading RSA key file `rsa_key.priv': No such file or directory
+
+@itemize
+@item You forgot to create a public/private keypair.
+@item Specify the complete pathname to the private key file with the @samp{PrivateKeyFile} option.
+@end itemize
+
+@item Warning: insecure file permissions for RSA private key file `rsa_key.priv'!
+
+@itemize
+@item The private key file is readable by users other than root.
+Use chmod to correct the file permissions.
+@end itemize
+
+@item Creating metasocket failed: Address family not supported
+
+@itemize
+@item By default tinc tries to create both IPv4 and IPv6 sockets.
+On some platforms this might not be implemented.
+If the logs show @samp{Ready} later on, then at least one metasocket was created,
+and you can ignore this message.
+You can add @samp{AddressFamily = ipv4} to @file{tinc.conf} to prevent this from happening.
+@end itemize
+
+@item Cannot route packet: unknown IPv4 destination 1.2.3.4
+
+@itemize
+@item You try to send traffic to a host on the VPN for which no Subnet is known.
+@item If it is a broadcast address (ending in .255), it probably is a samba server or a Windows host sending broadcast packets.
+You can ignore it.
+@end itemize
+
+@item Cannot route packet: ARP request for unknown address 1.2.3.4
+
+@itemize
+@item You try to send traffic to a host on the VPN for which no Subnet is known.
@end itemize
@item Packet with destination 1.2.3.4 is looping back to us!
@itemize
@item Something is not configured right. Packets are being sent out to the
-tap device, but according to the Subnet directives in your host configuration
+virtual network device, but according to the Subnet directives in your host configuration
file, those packets should go to your own host. Most common mistake is that
-you have a Subnet line in your host configuration file with a netmask which is
-just as large as the netmask of the tap device. The latter should in almost all
+you have a Subnet line in your host configuration file with a prefix length which is
+just as large as the prefix of the virtual network interface. The latter should in almost all
cases be larger. Rethink your configuration.
Note that you will only see this message if you specified a debug
level of 5 or higher!
-@item Chances are that a `Subnet = ...' line in the host configuration file of this tinc daemon is wrong.
+@item Chances are that a @samp{Subnet = ...} line in the host configuration file of this tinc daemon is wrong.
Change it to a subnet that is accepted locally by another interface,
or if that is not the case, try changing the prefix length into /32.
@end itemize
-@item Network doesn't work, syslog shows only packets of length 46
+@item Node foo (1.2.3.4) is not reachable
-@cindex arp
-@example
-Jan 1 12:00:00 host tinc.net[1234]: Read packet of length 46 from tap device
-Jan 1 12:00:00 host tinc.net[1234]: Trying to look up 0.0.192.168 in connection list failed!
-@end example
@itemize
-@item Add the `ifconfig $NETNAME -arp' to tinc-up.
+@item Node foo does not have a connection anymore, its tinc daemon is not running or its connection to the Internet is broken.
@end itemize
-@item Network address and subnet mask do not match!
+@item Received UDP packet from unknown source 1.2.3.4 (port 12345)
@itemize
-@item The Subnet field must contain a @emph{network} address.
-@item If you only want to use one IP address, set the netmask to /32.
+@item If you see this only sporadically, it is harmless and caused by a node sending packets using an old key.
@end itemize
-@item This is a bug: net.c:253: 24: Some error
+@item Got bad/bogus/unauthorized REQUEST from foo (1.2.3.4 port 12345)
@itemize
-@item This is something that should not have happened.
-Please report this, and tell us exactly what went wrong before you got
-this message. In normal operation, these errors should not occur.
+@item Node foo does not have the right public/private keypair.
+Generate new keypairs and distribute them again.
+@item An attacker tries to gain access to your VPN.
+@item A network error caused corruption of metadata sent from foo.
@end itemize
-@item Error reading RSA key file `rsa_key.priv': No such file or directory
+@end table
+
+@c ==================================================================
+@node Sending bug reports
+@section Sending bug reports
+
+If you really can't find the cause of a problem, or if you suspect tinc is not working right,
+you can send us a bugreport, see @ref{Contact information}.
+Be sure to include the following information in your bugreport:
@itemize
-@item You must specify the complete pathname.
-Specifying a relative path does not make sense here. tinc changes its
-directory to / when starting (to avoid keeping a mount point busy); and
-even if we built in a default directory to look for these files, the key
-files are bound to be in a different directory.
+@item A clear description of what you are trying to achieve and what the problem is.
+@item What platform (operating system, version, hardware architecture) and which version of tinc you use.
+@item If compiling tinc fails, a copy of @file{config.log} and the error messages you get.
+@item Otherwise, a copy of @file{tinc.conf}, @file{tinc-up} and all files in the @file{hosts/} directory.
+@item The output of the commands @samp{ifconfig -a} and @samp{route -n} (or @samp{netstat -rn} if that doesn't work).
+@item The output of any command that fails to work as it should (like ping or traceroute).
@end itemize
-@end table
-
@c ==================================================================
-@node Technical information, About us, Running tinc, Top
+@node Technical information
@chapter Technical information
@menu
-* The Connection::
+* The connection::
+* The meta-protocol::
* Security::
@end menu
@c ==================================================================
-@node The Connection, Security, Technical information, Technical information
-@section The basic philosophy of the way tinc works
-@cindex connection
+@node The connection
+@section The connection
-tinc is a daemon that takes VPN data and transmit that to another host
+@cindex connection
+Tinc is a daemon that takes VPN data and transmit that to another host
computer over the existing Internet infrastructure.
@menu
-* Protocol Preview::
-* The Meta-connection::
+* The UDP tunnel::
+* The meta-connection::
@end menu
@c ==================================================================
-@node Protocol Preview, The Meta-connection, The Connection, The Connection
-@subsection A preview of the way the tinc works
+@node The UDP tunnel
+@subsection The UDP tunnel
-@cindex ethertap
+@cindex virtual network device
@cindex frame type
The data itself is read from a character device file, the so-called
-@emph{ethertap} device. This device is associated with a network
+@emph{virtual network device}. This device is associated with a network
interface. Any data sent to this interface can be read from the device,
-and any data written to the device gets sent from the interface. Data to
-and from the device is formatted as if it were a normal Ethernet card,
-so a frame is preceded by two MAC addresses and a @emph{frame type}
-field.
+and any data written to the device gets sent from the interface.
+There are two possible types of virtual network devices:
+`tun' style, which are point-to-point devices which can only handle IPv4 and/or IPv6 packets,
+and `tap' style, which are Ethernet devices and handle complete Ethernet frames.
So when tinc reads an Ethernet frame from the device, it determines its
-type. Right now, tinc can only handle Internet Protocol version 4 (IPv4)
-frames, because it needs IP headers for routing.
-Plans to support other protocols and switching instead of routing are being made.
-(Some code for IPv6 routing and switching is already present but nonfunctional.)
-When tinc knows
-which type of frame it has read, it can also read the source and
-destination address from it.
-
-Now it is time that the frame gets encrypted. Currently the only
-encryption algorithm available is blowfish.
+type. When tinc is in it's default routing mode, it can handle IPv4 and IPv6
+packets. Depending on the Subnet lines, it will send the packets off to their destination IP address.
+In the `switch' and `hub' mode, tinc will use broadcasts and MAC address discovery
+to deduce the destination of the packets.
+Since the latter modes only depend on the link layer information,
+any protocol that runs over Ethernet is supported (for instance IPX and Appletalk).
+However, only `tap' style devices provide this information.
+
+After the destination has been determined,
+the packet will be compressed (optionally),
+a sequence number will be added to the packet,
+the packet will then be encrypted
+and a message authentication code will be appended.
@cindex encapsulating
@cindex UDP
-When the encryption is ready, time has come to actually transport the
+When that is done, time has come to actually transport the
packet to the destination computer. We do this by sending the packet
over an UDP connection to the destination host. This is called
@emph{encapsulating}, the VPN packet (though now encrypted) is
encapsulated in another IP datagram.
When the destination receives this packet, the same thing happens, only
-in reverse. So it does a decrypt on the contents of the UDP datagram,
-and it writes the decrypted information to its own ethertap device.
-
-To let the kernel on the receiving end accept the packet, the destination MAC
-address must match that of the tap interface. Because of the routing nature
-of tinc, ARP is not possible. tinc solves this by always overwriting the
-destination MAC address with fe:fd:0:0:0:0. That is also the reason why you must
-set the MAC address of your tap interface to that address.
+in reverse. So it checks the message authentication code, decrypts the contents of the UDP datagram,
+checks the sequence number
+and writes the decrypted information to its own virtual network device.
+
+If the virtual network device is a `tun' device (a point-to-point tunnel),
+there is no problem for the kernel to accept a packet.
+However, if it is a `tap' device (this is the only available type on FreeBSD),
+the destination MAC address must match that of the virtual network interface.
+If tinc is in it's default routing mode, ARP does not work, so the correct destination MAC
+can not be known by the sending host.
+Tinc solves this by letting the receiving end detect the MAC address of its own virtual network interface
+and overwriting the destination MAC address of the received packet.
+
+In switch or hub modes ARP does work so the sender already knows the correct destination MAC address.
+In those modes every interface should have a unique MAC address, so make sure they are not the same.
+Because switch and hub modes rely on MAC addresses to function correctly,
+these modes cannot be used on the following operating systems which don't have a `tap' style virtual network device:
+OpenBSD, NetBSD, Darwin and Solaris.
@c ==================================================================
-@node The Meta-connection, , Protocol Preview, The Connection
+@node The meta-connection
@subsection The meta-connection
-Having only an UDP connection available is not enough. Though suitable
+Having only a UDP connection available is not enough. Though suitable
for transmitting data, we want to be able to reliably send other
information, such as routing and session key information to somebody.
a timeout, both TCP streams would sense the timeout, and both would
start re-sending packets.
+
@c ==================================================================
-@node Security, , The Connection, Technical information
-@section About tinc's encryption and other security-related issues.
+@node The meta-protocol
+@section The meta-protocol
+
+The meta protocol is used to tie all tinc daemons together, and
+exchange information about which tinc daemon serves which virtual
+subnet.
+
+The meta protocol consists of requests that can be sent to the other
+side. Each request has a unique number and several parameters. All
+requests are represented in the standard ASCII character set. It is
+possible to use tools such as telnet or netcat to connect to a tinc
+daemon started with the --bypass-security option
+and to read and write requests by hand, provided that one
+understands the numeric codes sent.
+
+The authentication scheme is described in @ref{Authentication protocol}. After a
+successful authentication, the server and the client will exchange all the
+information about other tinc daemons and subnets they know of, so that both
+sides (and all the other tinc daemons behind them) have their information
+synchronised.
+
+@cindex ADD_EDGE
+@cindex ADD_SUBNET
+@example
+message
+------------------------------------------------------------------
+ADD_EDGE node1 node2 21.32.43.54 655 222 0
+ | | | | | +-> options
+ | | | | +----> weight
+ | | | +--------> UDP port of node2
+ | | +----------------> real address of node2
+ | +-------------------------> name of destination node
+ +-------------------------------> name of source node
+
+ADD_SUBNET node 192.168.1.0/24
+ | | +--> prefixlength
+ | +--------> network address
+ +------------------> owner of this subnet
+------------------------------------------------------------------
+@end example
+
+The ADD_EDGE messages are to inform other tinc daemons that a connection between
+two nodes exist. The address of the destination node is available so that
+VPN packets can be sent directly to that node.
+
+The ADD_SUBNET messages inform other tinc daemons that certain subnets belong
+to certain nodes. tinc will use it to determine to which node a VPN packet has
+to be sent.
+
+@cindex DEL_EDGE
+@cindex DEL_SUBNET
+@example
+message
+------------------------------------------------------------------
+DEL_EDGE node1 node2
+ | +----> name of destination node
+ +----------> name of source node
+
+DEL_SUBNET node 192.168.1.0/24
+ | | +--> prefixlength
+ | +--------> network address
+ +------------------> owner of this subnet
+------------------------------------------------------------------
+@end example
+
+In case a connection between two daemons is closed or broken, DEL_EDGE messages
+are sent to inform the other daemons of that fact. Each daemon will calculate a
+new route to the the daemons, or mark them unreachable if there isn't any.
+
+@cindex REQ_KEY
+@cindex ANS_KEY
+@cindex KEY_CHANGED
+@example
+message
+------------------------------------------------------------------
+REQ_KEY origin destination
+ | +--> name of the tinc daemon it wants the key from
+ +----------> name of the daemon that wants the key
+
+ANS_KEY origin destination 4ae0b0a82d6e0078 91 64 4
+ | | \______________/ | | +--> MAC length
+ | | | | +-----> digest algorithm
+ | | | +--------> cipher algorithm
+ | | +--> 128 bits key
+ | +--> name of the daemon that wants the key
+ +----------> name of the daemon that uses this key
+
+KEY_CHANGED origin
+ +--> daemon that has changed it's packet key
+------------------------------------------------------------------
+@end example
+
+The keys used to encrypt VPN packets are not sent out directly. This is
+because it would generate a lot of traffic on VPNs with many daemons, and
+chances are that not every tinc daemon will ever send a packet to every
+other daemon. Instead, if a daemon needs a key it sends a request for it
+via the meta connection of the nearest hop in the direction of the
+destination.
+
+@cindex PING
+@cindex PONG
+@example
+daemon message
+------------------------------------------------------------------
+origin PING
+dest. PONG
+------------------------------------------------------------------
+@end example
+
+There is also a mechanism to check if hosts are still alive. Since network
+failures or a crash can cause a daemon to be killed without properly
+shutting down the TCP connection, this is necessary to keep an up to date
+connection list. PINGs are sent at regular intervals, except when there
+is also some other traffic. A little bit of salt (random data) is added
+with each PING and PONG message, to make sure that long sequences of PING/PONG
+messages without any other traffic won't result in known plaintext.
+
+This basically covers what is sent over the meta connection by tinc.
+
+
+@c ==================================================================
+@node Security
+@section Security
@cindex TINC
@cindex Cabal
-tinc got its name from ``TINC,'' short for @emph{There Is No Cabal}; the
+Tinc got its name from ``TINC,'' short for @emph{There Is No Cabal}; the
alleged Cabal was/is an organisation that was said to keep an eye on the
entire Internet. As this is exactly what you @emph{don't} want, we named
the tinc project after TINC.
But in order to be ``immune'' to eavesdropping, you'll have to encrypt
your data. Because tinc is a @emph{Secure} VPN (SVPN) daemon, it does
exactly that: encrypt.
-tinc uses blowfish encryption in CBC mode and a small amount of salt
-at the beginning of each packet to make sure eavesdroppers cannot get
-any information at all from the packets they can intercept.
+Tinc by default uses blowfish encryption with 128 bit keys in CBC mode, 32 bit
+sequence numbers and 4 byte long message authentication codes to make sure
+eavesdroppers cannot get and cannot change any information at all from the
+packets they can intercept. The encryption algorithm and message authentication
+algorithm can be changed in the configuration. The length of the message
+authentication codes is also adjustable. The length of the key for the
+encryption algorithm is always the default length used by OpenSSL.
+
+@menu
+* Authentication protocol::
+* Encryption of network packets::
+* Security issues::
+@end menu
+
+
+@c ==================================================================
+@node Authentication protocol
+@subsection Authentication protocol
@cindex authentication
-Another important part is the authentication done prior to allowing other
-tinc daemons to connect. This is done by a challenge/response handshake
-involving RSA encryption.
-The details of the authentication can be found in a file called @file{doc/SECURITY2}
-in the source of tinc.
+A new scheme for authentication in tinc has been devised, which offers some
+improvements over the protocol used in 1.0pre2 and 1.0pre3. Explanation is
+below.
+
+@cindex ID
+@cindex META_KEY
+@cindex CHALLENGE
+@cindex CHAL_REPLY
+@cindex ACK
+@example
+daemon message
+--------------------------------------------------------------------------
+client <attempts connection>
+
+server <accepts connection>
+
+client ID client 12
+ | +---> version
+ +-------> name of tinc daemon
+
+server ID server 12
+ | +---> version
+ +-------> name of tinc daemon
+
+client META_KEY 5f0823a93e35b69e...7086ec7866ce582b
+ \_________________________________/
+ +-> RSAKEYLEN bits totally random string S1,
+ encrypted with server's public RSA key
+
+server META_KEY 6ab9c1640388f8f0...45d1a07f8a672630
+ \_________________________________/
+ +-> RSAKEYLEN bits totally random string S2,
+ encrypted with client's public RSA key
+
+From now on:
+ - the client will symmetrically encrypt outgoing traffic using S1
+ - the server will symmetrically encrypt outgoing traffic using S2
+
+client CHALLENGE da02add1817c1920989ba6ae2a49cecbda0
+ \_________________________________/
+ +-> CHALLEN bits totally random string H1
+
+server CHALLENGE 57fb4b2ccd70d6bb35a64c142f47e61d57f
+ \_________________________________/
+ +-> CHALLEN bits totally random string H2
+
+client CHAL_REPLY 816a86
+ +-> 160 bits SHA1 of H2
+
+server CHAL_REPLY 928ffe
+ +-> 160 bits SHA1 of H1
+
+After the correct challenge replies are received, both ends have proved
+their identity. Further information is exchanged.
+
+client ACK 655 123 0
+ | | +-> options
+ | +----> estimated weight
+ +--------> listening port of client
+
+server ACK 655 321 0
+ | | +-> options
+ | +----> estimated weight
+ +--------> listening port of server
+--------------------------------------------------------------------------
+@end example
+
+This new scheme has several improvements, both in efficiency and security.
+
+First of all, the server sends exactly the same kind of messages over the wire
+as the client. The previous versions of tinc first authenticated the client,
+and then the server. This scheme even allows both sides to send their messages
+simultaneously, there is no need to wait for the other to send something first.
+This means that any calculations that need to be done upon sending or receiving
+a message can also be done in parallel. This is especially important when doing
+RSA encryption/decryption. Given that these calculations are the main part of
+the CPU time spent for the authentication, speed is improved by a factor 2.
+
+Second, only one RSA encrypted message is sent instead of two. This reduces the
+amount of information attackers can see (and thus use for a cryptographic
+attack). It also improves speed by a factor two, making the total speedup a
+factor 4.
+
+Third, and most important:
+The symmetric cipher keys are exchanged first, the challenge is done
+afterwards. In the previous authentication scheme, because a man-in-the-middle
+could pass the challenge/chal_reply phase (by just copying the messages between
+the two real tinc daemons), but no information was exchanged that was really
+needed to read the rest of the messages, the challenge/chal_reply phase was of
+no real use. The man-in-the-middle was only stopped by the fact that only after
+the ACK messages were encrypted with the symmetric cipher. Potentially, it
+could even send it's own symmetric key to the server (if it knew the server's
+public key) and read some of the metadata the server would send it (it was
+impossible for the mitm to read actual network packets though). The new scheme
+however prevents this.
+
+This new scheme makes sure that first of all, symmetric keys are exchanged. The
+rest of the messages are then encrypted with the symmetric cipher. Then, each
+side can only read received messages if they have their private key. The
+challenge is there to let the other side know that the private key is really
+known, because a challenge reply can only be sent back if the challenge is
+decrypted correctly, and that can only be done with knowledge of the private
+key.
+
+Fourth: the first thing that is sent via the symmetric cipher encrypted
+connection is a totally random string, so that there is no known plaintext (for
+an attacker) in the beginning of the encrypted stream.
+
+
+@c ==================================================================
+@node Encryption of network packets
+@subsection Encryption of network packets
+@cindex encryption
+
+A data packet can only be sent if the encryption key is known to both
+parties, and the connection is activated. If the encryption key is not
+known, a request is sent to the destination using the meta connection
+to retrieve it. The packet is stored in a queue while waiting for the
+key to arrive.
+
+@cindex UDP
+The UDP packet containing the network packet from the VPN has the following layout:
+
+@example
+... | IP header | UDP header | seqno | VPN packet | MAC | UDP trailer
+ \___________________/\_____/
+ | |
+ V +---> digest algorithm
+ Encrypted with symmetric cipher
+@end example
+So, the entire VPN packet is encrypted using a symmetric cipher, including a 32 bits
+sequence number that is added in front of the actual VPN packet, to act as a unique
+IV for each packet and to prevent replay attacks. A message authentication code
+is added to the UDP packet to prevent alteration of packets. By default the
+first 4 bytes of the digest are used for this, but this can be changed using
+the MACLength configuration variable.
@c ==================================================================
-@node About us, Concept Index, Technical information, Top
+@node Security issues
+@subsection Security issues
+
+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
+uses strong authentication with RSA keys.
+
+On the 29th of December 2001, Jerome Etienne posted a security analysis of tinc
+1.0pre4. Due to a lack of sequence numbers and a message authentication code
+for each packet, an attacker could possibly disrupt certain network services or
+launch a denial of service attack by replaying intercepted packets. The current
+version adds sequence numbers and message authentication codes to prevent such
+attacks.
+
+On the 15th of September 2003, Peter Gutmann posted a security analysis of tinc
+1.0.1. He argues that the 32 bit sequence number used by tinc is not a good IV,
+that tinc's default length of 4 bytes for the MAC is too short, and he doesn't
+like tinc's use of RSA during authentication. We do not know of a security hole
+in this version of tinc, but tinc's security is not as strong as TLS or IPsec.
+We will address these issues in tinc 2.0.
+
+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.
+
+
+@c ==================================================================
+@node Platform specific information
+@chapter Platform specific information
+
+@menu
+* Interface configuration::
+* Routes::
+@end menu
+
+@c ==================================================================
+@node Interface configuration
+@section Interface configuration
+
+When configuring an interface, one normally assigns it an address and a
+netmask. The address uniquely identifies the host on the network attached to
+the interface. The netmask, combined with the address, forms a subnet. It is
+used to add a route to the routing table instructing the kernel to send all
+packets which fall into that subnet to that interface. Because all packets for
+the entire VPN should go to the virtual network interface used by tinc, the
+netmask should be such that it encompasses the entire VPN.
+
+For IPv4 addresses:
+
+@multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
+@item Linux
+@tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
+@item Linux iproute2
+@tab @code{ip addr add} @var{address}@code{/}@var{prefixlength} @code{dev} @var{interface}
+@item FreeBSD
+@tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
+@item OpenBSD
+@tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
+@item NetBSD
+@tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
+@item Solaris
+@tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
+@item Darwin (MacOS/X)
+@tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
+@item Windows
+@tab @code{netsh interface ip set address} @var{interface} @code{static} @var{address} @var{netmask}
+@end multitable
+
+
+For IPv6 addresses:
+
+@multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
+@item Linux
+@tab @code{ifconfig} @var{interface} @code{add} @var{address}@code{/}@var{prefixlength}
+@item FreeBSD
+@tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
+@item OpenBSD
+@tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
+@item NetBSD
+@tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
+@item Solaris
+@tab @code{ifconfig} @var{interface} @code{inet6 plumb up}
+@item
+@tab @code{ifconfig} @var{interface} @code{inet6 addif} @var{address} @var{address}
+@item Darwin (MacOS/X)
+@tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
+@item Windows
+@tab @code{netsh interface ipv6 add address} @var{interface} @code{static} @var{address}/@var{prefixlength}
+@end multitable
+
+
+@c ==================================================================
+@node Routes
+@section Routes
+
+In some cases it might be necessary to add more routes to the virtual network
+interface. There are two ways to indicate which interface a packet should go
+to, one is to use the name of the interface itself, another way is to specify
+the (local) address that is assigned to that interface (@var{local_address}). The
+former way is unambiguous and therefore preferable, but not all platforms
+support this.
+
+Adding routes to IPv4 subnets:
+
+@multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
+@item Linux
+@tab @code{route add -net} @var{network_address} @code{netmask} @var{netmask} @var{interface}
+@item Linux iproute2
+@tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
+@item FreeBSD
+@tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
+@item OpenBSD
+@tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
+@item NetBSD
+@tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
+@item Solaris
+@tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
+@item Darwin (MacOS/X)
+@tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
+@item Windows
+@tab @code{netsh routing ip add persistentroute} @var{network_address} @var{netmask} @var{interface} @var{local_address}
+@end multitable
+
+Adding routes to IPv6 subnets:
+
+@multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
+@item Linux
+@tab @code{route add -A inet6} @var{network_address}@code{/}@var{prefixlength} @var{interface}
+@item Linux iproute2
+@tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
+@item FreeBSD
+@tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
+@item OpenBSD
+@tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
+@item NetBSD
+@tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
+@item Solaris
+@tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
+@item Darwin (MacOS/X)
+@tab ?
+@item Windows
+@tab @code{netsh interface ipv6 add route} @var{network address}/@var{prefixlength} @var{interface}
+@end multitable
+
+
+@c ==================================================================
+@node About us
@chapter About us
@menu
-* Contact Information::
+* Contact information::
* Authors::
@end menu
@c ==================================================================
-@node Contact Information, Authors, About us, About us
+@node Contact information
@section Contact information
@cindex website
-tinc's website is at @url{http://tinc.nl.linux.org/},
+Tinc's website is at @url{http://www.tinc-vpn.org/},
this server is located in the Netherlands.
@cindex IRC
-We have an IRC channel on the Open Projects IRC network. Connect to
-@uref{http://openprojects.nu/services/irc.html, irc.openprojects.net},
+We have an IRC channel on the FreeNode and OFTC IRC networks. Connect to
+@uref{http://www.freenode.net/, irc.freenode.net}
+or
+@uref{http://www.oftc.net/, irc.oftc.net}
and join channel #tinc.
@c ==================================================================
-@node Authors, , Contact Information, About us
+@node Authors
@section Authors
@table @asis
-@item Ivo Timmermans (zarq) (@email{itimmermans@@bigfoot.com})
-Main coder/hacker and maintainer of the package.
-
-@item Guus Sliepen (guus) (@email{guus@@sliepen.warande.net})
-Originator of it all, co-author.
-
-@item Wessel Dankers (Ubiq) (@email{wsl@@nl.linux.org})
-For the name `tinc' and various suggestions.
-
+@item Ivo Timmermans (zarq)
+@item Guus Sliepen (guus) (@email{guus@@tinc-vpn.org})
@end table
We have received a lot of valuable input from users. With their help,
@c ==================================================================
-@node Concept Index, , About us, Top
-@c node-name, next, previous, up
+@node Concept Index
@unnumbered Concept Index
@c ==================================================================
projects / tinc / blobdiff