1 \input texinfo @c -*-texinfo-*-
9 @include tincinclude.texi
12 @dircategory Networking tools
14 * tinc: (tinc). The tinc Manual.
17 This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
19 Copyright @copyright{} 1998-2006 Ivo Timmermans,
20 Guus Sliepen <guus@@tinc-vpn.org> and
21 Wessel Dankers <wsl@@tinc-vpn.org>.
25 Permission is granted to make and distribute verbatim copies of this
26 manual provided the copyright notice and this permission notice are
27 preserved on all copies.
29 Permission is granted to copy and distribute modified versions of this
30 manual under the conditions for verbatim copying, provided that the
31 entire resulting derived work is distributed under the terms of a
32 permission notice identical to this one.
38 @subtitle Setting up a Virtual Private Network with tinc
39 @author Ivo Timmermans and Guus Sliepen
42 @vskip 0pt plus 1filll
44 This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
46 Copyright @copyright{} 1998-2007 Ivo Timmermans,
47 Guus Sliepen <guus@@tinc-vpn.org> and
48 Wessel Dankers <wsl@@tinc-vpn.org>.
52 Permission is granted to make and distribute verbatim copies of this
53 manual provided the copyright notice and this permission notice are
54 preserved on all copies.
56 Permission is granted to copy and distribute modified versions of this
57 manual under the conditions for verbatim copying, provided that the
58 entire resulting derived work is distributed under the terms of a
59 permission notice identical to this one.
64 @c ==================================================================
74 * Technical information::
75 * Platform specific information::
77 * Concept Index:: All used terms explained
81 @c ==================================================================
86 Tinc is a Virtual Private Network (VPN) daemon that uses tunneling and
87 encryption to create a secure private network between hosts on the
90 Because the tunnel appears to the IP level network code as a normal
91 network device, there is no need to adapt any existing software.
92 The encrypted tunnels allows VPN sites to share information with each other
93 over the Internet without exposing any information to others.
95 This document is the manual for tinc. Included are chapters on how to
96 configure your computer to use tinc, as well as the configuration
97 process of tinc itself.
100 * Virtual Private Networks::
102 * Supported platforms::
105 @c ==================================================================
106 @node Virtual Private Networks
107 @section Virtual Private Networks
110 A Virtual Private Network or VPN is a network that can only be accessed
111 by a few elected computers that participate. This goal is achievable in
112 more than just one way.
115 Private networks can consist of a single stand-alone Ethernet LAN. Or
116 even two computers hooked up using a null-modem cable. In these cases,
118 obvious that the network is @emph{private}, no one can access it from the
119 outside. But if your computers are linked to the Internet, the network
120 is not private anymore, unless one uses firewalls to block all private
121 traffic. But then, there is no way to send private data to trusted
122 computers on the other end of the Internet.
125 This problem can be solved by using @emph{virtual} networks. Virtual
126 networks can live on top of other networks, but they use encapsulation to
127 keep using their private address space so they do not interfere with
128 the Internet. Mostly, virtual networks appear like a singe LAN, even though
129 they can span the entire world. But virtual networks can't be secured
130 by using firewalls, because the traffic that flows through it has to go
131 through the Internet, where other people can look at it.
133 As is the case with either type of VPN, anybody could eavesdrop. Or
134 worse, alter data. Hence it's probably advisable to encrypt the data
135 that flows over the network.
137 When one introduces encryption, we can form a true VPN. Other people may
138 see encrypted traffic, but if they don't know how to decipher it (they
139 need to know the key for that), they cannot read the information that flows
140 through the VPN. This is what tinc was made for.
143 @c ==================================================================
148 I really don't quite remember what got us started, but it must have been
149 Guus' idea. He wrote a simple implementation (about 50 lines of C) that
150 used the ethertap device that Linux knows of since somewhere
151 about kernel 2.1.60. It didn't work immediately and he improved it a
152 bit. At this stage, the project was still simply called "vpnd".
154 Since then, a lot has changed---to say the least.
157 Tinc now supports encryption, it consists of a single daemon (tincd) for
158 both the receiving and sending end, it has become largely
159 runtime-configurable---in short, it has become a full-fledged
160 professional package.
162 @cindex traditional VPNs
164 Tinc also allows more than two sites to connect to eachother and form a single VPN.
165 Traditionally VPNs are created by making tunnels, which only have two endpoints.
166 Larger VPNs with more sites are created by adding more tunnels.
167 Tinc takes another approach: only endpoints are specified,
168 the software itself will take care of creating the tunnels.
169 This allows for easier configuration and improved scalability.
171 A lot can---and will be---changed. We have a number of things that we would like to
172 see in the future releases of tinc. Not everything will be available in
173 the near future. Our first objective is to make tinc work perfectly as
174 it stands, and then add more advanced features.
176 Meanwhile, we're always open-minded towards new ideas. And we're
180 @c ==================================================================
181 @node Supported platforms
182 @section Supported platforms
185 Tinc has been verified to work under Linux, FreeBSD, OpenBSD, NetBSD, MacOS/X (Darwin), Solaris, and Windows (both natively and in a Cygwin environment),
186 with various hardware architectures. These are some of the platforms
187 that are supported by the universal tun/tap device driver or other virtual network device drivers.
188 Without such a driver, tinc will most
189 likely compile and run, but it will not be able to send or receive data
193 For an up to date list of supported platforms, please check the list on
195 @uref{http://www.tinc-vpn.org/platforms}.
203 @c Preparing your system
210 @c ==================================================================
212 @chapter Preparations
214 This chapter contains information on how to prepare your system to
218 * Configuring the kernel::
223 @c ==================================================================
224 @node Configuring the kernel
225 @section Configuring the kernel
228 * Configuration of Linux kernels 2.1.60 up to 2.4.0::
229 * Configuration of Linux kernels 2.4.0 and higher::
230 * Configuration of FreeBSD kernels::
231 * Configuration of OpenBSD kernels::
232 * Configuration of NetBSD kernels::
233 * Configuration of Solaris kernels::
234 * Configuration of Darwin (MacOS/X) kernels::
235 * Configuration of Windows::
239 @c ==================================================================
240 @node Configuration of Linux kernels 2.1.60 up to 2.4.0
241 @subsection Configuration of Linux kernels 2.1.60 up to 2.4.0
244 For kernels up to 2.4.0, you need a kernel that supports the ethertap device.
245 Most distributions come with kernels that already support this.
246 If not, here are the options you have to turn on when configuring a new kernel:
249 Code maturity level options
250 [*] Prompt for development and/or incomplete code/drivers
252 [*] Kernel/User netlink socket
253 <M> Netlink device emulation
254 Network device support
255 <M> Ethertap network tap
258 If you want to run more than one instance of tinc or other programs that use
259 the ethertap, you have to compile the ethertap driver as a module, otherwise
260 you can also choose to compile it directly into the kernel.
262 If you decide to build any of these as dynamic kernel modules, it's a good idea
263 to add these lines to @file{/etc/modules.conf}:
266 alias char-major-36 netlink_dev
268 options tap0 -o tap0 unit=0
270 options tap1 -o tap1 unit=1
272 alias tap@emph{N} ethertap
273 options tap@emph{N} -o tap@emph{N} unit=@emph{N}
276 Add as much alias/options lines as necessary.
279 @c ==================================================================
280 @node Configuration of Linux kernels 2.4.0 and higher
281 @subsection Configuration of Linux kernels 2.4.0 and higher
283 @cindex Universal tun/tap
284 For kernels 2.4.0 and higher, you need a kernel that supports the Universal tun/tap device.
285 Most distributions come with kernels that already support this.
286 Here are the options you have to turn on when configuring a new kernel:
289 Code maturity level options
290 [*] Prompt for development and/or incomplete code/drivers
291 Network device support
292 <M> Universal tun/tap device driver support
295 It's not necessary to compile this driver as a module, even if you are going to
296 run more than one instance of tinc.
298 If you have an early 2.4 kernel, you can choose both the tun/tap driver and the
299 `Ethertap network tap' device. This latter is marked obsolete, and chances are
300 that it won't even function correctly anymore. Make sure you select the
301 universal tun/tap driver.
303 If you decide to build the tun/tap driver as a kernel module, add these lines
304 to @file{/etc/modules.conf}:
307 alias char-major-10-200 tun
311 @c ==================================================================
312 @node Configuration of FreeBSD kernels
313 @subsection Configuration of FreeBSD kernels
315 For FreeBSD version 4.1 and higher, tun and tap drivers are included in the default kernel configuration.
316 Using tap devices is recommended.
319 @c ==================================================================
320 @node Configuration of OpenBSD kernels
321 @subsection Configuration of OpenBSD kernels
323 For OpenBSD version 2.9 and higher,
324 the tun driver is included in the default kernel configuration.
325 There is also a kernel patch from @uref{http://diehard.n-r-g.com/stuff/openbsd/}
326 which adds a tap device to OpenBSD.
327 This should work with tinc.
330 @c ==================================================================
331 @node Configuration of NetBSD kernels
332 @subsection Configuration of NetBSD kernels
334 For NetBSD version 1.5.2 and higher,
335 the tun driver is included in the default kernel configuration.
337 Tunneling IPv6 may not work on NetBSD's tun device.
340 @c ==================================================================
341 @node Configuration of Solaris kernels
342 @subsection Configuration of Solaris kernels
344 For Solaris 8 (SunOS 5.8) and higher,
345 the tun driver may or may not be included in the default kernel configuration.
346 If it isn't, the source can be downloaded from @uref{http://vtun.sourceforge.net/tun/}.
347 For x86 and sparc64 architectures, precompiled versions can be found at @uref{http://www.monkey.org/~dugsong/fragroute/}.
348 If the @file{net/if_tun.h} header file is missing, install it from the source package.
351 @c ==================================================================
352 @node Configuration of Darwin (MacOS/X) kernels
353 @subsection Configuration of Darwin (MacOS/X) kernels
355 Tinc on Darwin relies on a tunnel driver for its data acquisition from the kernel.
356 Tinc supports either the driver from @uref{http://www-user.rhrk.uni-kl.de/~nissler/tuntap/},
357 which supports both tun and tap style devices,
358 and also the driver from from @uref{http://chrisp.de/en/projects/tunnel.html}.
359 The former driver is recommended.
360 The tunnel driver must be loaded before starting tinc with the following command:
367 @c ==================================================================
368 @node Configuration of Windows
369 @subsection Configuration of Windows
371 You will need to install the latest TAP-Win32 driver from OpenVPN.
372 You can download it from @uref{http://openvpn.sourceforge.net}.
373 Using the Network Connections control panel,
374 configure the TAP-Win32 network interface in the same way as you would do from the tinc-up script,
375 as explained in the rest of the documentation.
378 @c ==================================================================
384 Before you can configure or build tinc, you need to have the OpenSSL,
385 zlib and lzo libraries installed on your system. If you try to configure tinc without
386 having them installed, configure will give you an error message, and stop.
396 @c ==================================================================
401 For all cryptography-related functions, tinc uses the functions provided
402 by the OpenSSL library.
404 If this library is not installed, you wil get an error when configuring
405 tinc for build. Support for running tinc without having OpenSSL
406 installed @emph{may} be added in the future.
408 You can use your operating system's package manager to install this if
409 available. Make sure you install the development AND runtime versions
412 If you have to install OpenSSL manually, you can get the source code
413 from @url{http://www.openssl.org/}. Instructions on how to configure,
414 build and install this package are included within the package. Please
415 make sure you build development and runtime libraries (which is the
418 If you installed the OpenSSL libraries from source, it may be necessary
419 to let configure know where they are, by passing configure one of the
420 --with-openssl-* parameters.
423 --with-openssl=DIR OpenSSL library and headers prefix
424 --with-openssl-include=DIR OpenSSL headers directory
425 (Default is OPENSSL_DIR/include)
426 --with-openssl-lib=DIR OpenSSL library directory
427 (Default is OPENSSL_DIR/lib)
431 @subsubheading License
434 The complete source code of tinc is covered by the GNU GPL version 2.
435 Since the license under which OpenSSL is distributed is not directly
436 compatible with the terms of the GNU GPL
437 @uref{http://www.openssl.org/support/faq.html#LEGAL2}, we
438 include an exemption to the GPL (see also the file COPYING.README) to allow
439 everyone to create a statically or dynamically linked executable:
442 This program is released under the GPL with the additional exemption
443 that compiling, linking, and/or using OpenSSL is allowed. You may
444 provide binary packages linked to the OpenSSL libraries, provided that
445 all other requirements of the GPL are met.
448 Since the LZO library used by tinc is also covered by the GPL,
449 we also present the following exemption:
452 Hereby I grant a special exception to the tinc VPN project
453 (http://www.tinc-vpn.org/) to link the LZO library with the OpenSSL library
454 (http://www.openssl.org).
456 Markus F.X.J. Oberhumer
460 @c ==================================================================
465 For the optional compression of UDP packets, tinc uses the functions provided
468 If this library is not installed, you wil get an error when configuring
469 tinc for build. Support for running tinc without having zlib
470 installed @emph{may} be added in the future.
472 You can use your operating system's package manager to install this if
473 available. Make sure you install the development AND runtime versions
476 If you have to install zlib manually, you can get the source code
477 from @url{http://www.gzip.org/zlib/}. Instructions on how to configure,
478 build and install this package are included within the package. Please
479 make sure you build development and runtime libraries (which is the
483 @c ==================================================================
488 Another form of compression is offered using the lzo library.
490 If this library is not installed, you wil get an error when configuring
491 tinc for build. Support for running tinc without having lzo
492 installed @emph{may} be added in the future.
494 You can use your operating system's package manager to install this if
495 available. Make sure you install the development AND runtime versions
498 If you have to install lzo manually, you can get the source code
499 from @url{http://www.oberhumer.com/opensource/lzo/}. Instructions on how to configure,
500 build and install this package are included within the package. Please
501 make sure you build development and runtime libraries (which is the
505 @c ==================================================================
510 For the main event loop, tinc uses the libevent library.
512 If this library is not installed, you wil get an error when configuring
515 You can use your operating system's package manager to install this if
516 available. Make sure you install the development AND runtime versions
519 If you have to install libevent manually, you can get the source code
520 from @url{http://monkey.org/~provos/libevent/}. Instructions on how to configure,
521 build and install this package are included within the package. Please
522 make sure you build development and runtime libraries (which is the
535 @c ==================================================================
537 @chapter Installation
539 If you use Debian, you may want to install one of the
540 precompiled packages for your system. These packages are equipped with
541 system startup scripts and sample configurations.
543 If you cannot use one of the precompiled packages, or you want to compile tinc
544 for yourself, you can use the source. The source is distributed under
545 the GNU General Public License (GPL). Download the source from the
546 @uref{http://www.tinc-vpn.org/download, download page}, which has
547 the checksums of these files listed; you may wish to check these with
548 md5sum before continuing.
550 Tinc comes in a convenient autoconf/automake package, which you can just
551 treat the same as any other package. Which is just untar it, type
552 `./configure' and then `make'.
553 More detailed instructions are in the file @file{INSTALL}, which is
554 included in the source distribution.
557 * Building and installing tinc::
562 @c ==================================================================
563 @node Building and installing tinc
564 @section Building and installing tinc
566 Detailed instructions on configuring the source, building tinc and installing tinc
567 can be found in the file called @file{INSTALL}.
569 @cindex binary package
570 If you happen to have a binary package for tinc for your distribution,
571 you can use the package management tools of that distribution to install tinc.
572 The documentation that comes along with your distribution will tell you how to do that.
575 * Darwin (MacOS/X) build environment::
576 * Cygwin (Windows) build environment::
577 * MinGW (Windows) build environment::
581 @c ==================================================================
582 @node Darwin (MacOS/X) build environment
583 @subsection Darwin (MacOS/X) build environment
585 In order to build tinc on Darwin, you need to install the MacOS/X Developer Tools
586 from @uref{http://developer.apple.com/tools/macosxtools.html} and
587 a recent version of Fink from @uref{http://fink.sourceforge.net/}.
589 After installation use fink to download and install the following packages:
590 autoconf25, automake, dlcompat, m4, openssl, zlib and lzo.
592 @c ==================================================================
593 @node Cygwin (Windows) build environment
594 @subsection Cygwin (Windows) build environment
596 If Cygwin hasn't already been installed, install it directly from
597 @uref{http://www.cygwin.com/}.
599 When tinc is compiled in a Cygwin environment, it can only be run in this environment,
600 but all programs, including those started outside the Cygwin environment, will be able to use the VPN.
601 It will also support all features.
603 @c ==================================================================
604 @node MinGW (Windows) build environment
605 @subsection MinGW (Windows) build environment
607 You will need to install the MinGW environment from @uref{http://www.mingw.org}.
609 When tinc is compiled using MinGW it runs natively under Windows,
610 it is not necessary to keep MinGW installed.
612 When detaching, tinc will install itself as a service,
613 which will be restarted automatically after reboots.
616 @c ==================================================================
618 @section System files
620 Before you can run tinc, you must make sure you have all the needed
621 files on your system.
629 @c ==================================================================
631 @subsection Device files
634 First, you'll need the special device file(s) that form the interface
635 between the kernel and the daemon.
637 The permissions for these files have to be such that only the super user
638 may read/write to this file. You'd want this, because otherwise
639 eavesdropping would become a bit too easy. This does, however, imply
640 that you'd have to run tincd as root.
642 If you use Linux and have a kernel version prior to 2.4.0, you have to make the
646 mknod -m 600 /dev/tap0 c 36 16
647 mknod -m 600 /dev/tap1 c 36 17
649 mknod -m 600 /dev/tap@emph{N} c 36 @emph{N+16}
652 There is a maximum of 16 ethertap devices.
654 If you use the universal tun/tap driver, you have to create the
655 following device file (unless it already exist):
658 mknod -m 600 /dev/tun c 10 200
661 If you use Linux, and you run the new 2.4 kernel using the devfs filesystem,
662 then the tun/tap device will probably be automatically generated as
665 Unlike the ethertap device, you do not need multiple device files if
666 you are planning to run multiple tinc daemons.
669 @c ==================================================================
671 @subsection Other files
673 @subsubheading @file{/etc/networks}
675 You may add a line to @file{/etc/networks} so that your VPN will get a
676 symbolic name. For example:
682 @subsubheading @file{/etc/services}
685 You may add this line to @file{/etc/services}. The effect is that you
686 may supply a @samp{tinc} as a valid port number to some programs. The
687 number 655 is registered with the IANA.
692 # Ivo Timmermans <ivo@@tinc-vpn.org>
707 @c ==================================================================
709 @chapter Configuration
712 * Configuration introduction::
713 * Multiple networks::
714 * How connections work::
715 * Configuration files::
716 * Generating keypairs::
717 * Network interfaces::
718 * Example configuration::
721 @c ==================================================================
722 @node Configuration introduction
723 @section Configuration introduction
725 Before actually starting to configure tinc and editing files,
726 make sure you have read this entire section so you know what to expect.
727 Then, make it clear to yourself how you want to organize your VPN:
728 What are the nodes (computers running tinc)?
729 What IP addresses/subnets do they have?
730 What is the network mask of the entire VPN?
731 Do you need special firewall rules?
732 Do you have to set up masquerading or forwarding rules?
733 Do you want to run tinc in router mode or switch mode?
734 These questions can only be answered by yourself,
735 you will not find the answers in this documentation.
736 Make sure you have an adequate understanding of networks in general.
737 @cindex Network Administrators Guide
738 A good resource on networking is the
739 @uref{http://www.linuxdoc.org/LDP/nag2/, Linux Network Administrators Guide}.
741 If you have everything clearly pictured in your mind,
742 proceed in the following order:
743 First, generate the configuration files (@file{tinc.conf}, your host configuration file, @file{tinc-up} and perhaps @file{tinc-down}).
744 Then generate the keypairs.
745 Finally, distribute the host configuration files.
746 These steps are described in the subsections below.
749 @c ==================================================================
750 @node Multiple networks
751 @section Multiple networks
753 @cindex multiple networks
755 In order to allow you to run more than one tinc daemon on one computer,
756 for instance if your computer is part of more than one VPN,
757 you can assign a @var{netname} to your VPN.
758 It is not required if you only run one tinc daemon,
759 it doesn't even have to be the same on all the sites of your VPN,
760 but it is recommended that you choose one anyway.
762 We will asume you use a netname throughout this document.
763 This means that you call tincd with the -n argument,
764 which will assign a netname to this daemon.
766 The effect of this is that the daemon will set its configuration
767 root to @file{@value{sysconfdir}/tinc/@var{netname}/}, where @var{netname} is your argument to the -n
768 option. You'll notice that it appears in syslog as @file{tinc.@var{netname}}.
770 However, it is not strictly necessary that you call tinc with the -n
771 option. In this case, the network name would just be empty, and it will
772 be used as such. tinc now looks for files in @file{@value{sysconfdir}/tinc/}, instead of
773 @file{@value{sysconfdir}/tinc/@var{netname}/}; the configuration file should be @file{@value{sysconfdir}/tinc/tinc.conf},
774 and the host configuration files are now expected to be in @file{@value{sysconfdir}/tinc/hosts/}.
776 But it is highly recommended that you use this feature of tinc, because
777 it will be so much clearer whom your daemon talks to. Hence, we will
778 assume that you use it.
781 @c ==================================================================
782 @node How connections work
783 @section How connections work
785 When tinc starts up, it parses the command-line options and then
786 reads in the configuration file tinc.conf.
787 If it sees one or more `ConnectTo' values pointing to other tinc daemons in that file,
788 it will try to connect to those other daemons.
789 Whether this succeeds or not and whether `ConnectTo' is specified or not,
790 tinc will listen for incoming connection from other deamons.
791 If you did specify a `ConnectTo' value and the other side is not responding,
792 tinc will keep retrying.
793 This means that once started, tinc will stay running until you tell it to stop,
794 and failures to connect to other tinc daemons will not stop your tinc daemon
795 for trying again later.
796 This means you don't have to intervene if there are temporary network problems.
800 There is no real distinction between a server and a client in tinc.
801 If you wish, you can view a tinc daemon without a `ConnectTo' value as a server,
802 and one which does specify such a value as a client.
803 It does not matter if two tinc daemons have a `ConnectTo' value pointing to each other however.
806 @c ==================================================================
807 @node Configuration files
808 @section Configuration files
810 The actual configuration of the daemon is done in the file
811 @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf} and at least one other file in the directory
812 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/}.
814 These file consists of comments (lines started with a #) or assignments
821 The variable names are case insensitive, and any spaces, tabs, newlines
822 and carriage returns are ignored. Note: it is not required that you put
823 in the `=' sign, but doing so improves readability. If you leave it
824 out, remember to replace it with at least one space character.
826 In this section all valid variables are listed in alphabetical order.
827 The default value is given between parentheses,
828 other comments are between square brackets.
831 * Main configuration variables::
832 * Host configuration variables::
838 @c ==================================================================
839 @node Main configuration variables
840 @subsection Main configuration variables
843 @cindex AddressFamily
844 @item AddressFamily = <ipv4|ipv6|any> (any)
845 This option affects the address family of listening and outgoing sockets.
846 If any is selected, then depending on the operating system
847 both IPv4 and IPv6 or just IPv6 listening sockets will be created.
849 @cindex BindToAddress
850 @item BindToAddress = <@var{address}> [experimental]
851 If your computer has more than one IPv4 or IPv6 address, tinc
852 will by default listen on all of them for incoming connections.
853 It is possible to bind only to a single address with this variable.
855 This option may not work on all platforms.
857 @cindex BindToInterface
858 @item BindToInterface = <@var{interface}> [experimental]
859 If you have more than one network interface in your computer, tinc will
860 by default listen on all of them for incoming connections. It is
861 possible to bind tinc to a single interface like eth0 or ppp0 with this
864 This option may not work on all platforms.
867 @item ConnectTo = <@var{name}>
868 Specifies which other tinc daemon to connect to on startup.
869 Multiple ConnectTo variables may be specified,
870 in which case outgoing connections to each specified tinc daemon are made.
871 The names should be known to this tinc daemon
872 (i.e., there should be a host configuration file for the name on the ConnectTo line).
874 If you don't specify a host with ConnectTo,
875 tinc won't try to connect to other daemons at all,
876 and will instead just listen for incoming connections.
879 @item Device = <@var{device}> (@file{/dev/tap0}, @file{/dev/net/tun} or other depending on platform)
880 The virtual network device to use.
881 Tinc will automatically detect what kind of device it is.
882 Note that you can only use one device per daemon.
883 Under Windows, use @var{Interface} instead of @var{Device}.
884 Note that you can only use one device per daemon.
885 See also @ref{Device files}.
887 @cindex GraphDumpFile
888 @item GraphDumpFile = <@var{filename}> [experimental]
889 If this option is present,
890 tinc will dump the current network graph to the file @var{filename}
891 every minute, unless there were no changes to the graph.
892 The file is in a format that can be read by graphviz tools.
893 If @var{filename} starts with a pipe symbol |,
894 then the rest of the filename is interpreted as a shell command
895 that is executed, the graph is then sent to stdin.
898 @item Hostnames = <yes|no> (no)
899 This option selects whether IP addresses (both real and on the VPN)
900 should be resolved. Since DNS lookups are blocking, it might affect
901 tinc's efficiency, even stopping the daemon for a few seconds everytime
902 it does a lookup if your DNS server is not responding.
904 This does not affect resolving hostnames to IP addresses from the
908 @item Interface = <@var{interface}>
909 Defines the name of the interface corresponding to the virtual network device.
910 Depending on the operating system and the type of device this may or may not actually set the name of the interface.
911 Under Windows, this variable is used to select which network interface will be used.
912 If you specified a Device, this variable is almost always already correctly set.
915 @item Mode = <router|switch|hub> (router)
916 This option selects the way packets are routed to other daemons.
922 variables in the host configuration files will be used to form a routing table.
923 Only unicast packets of routable protocols (IPv4 and IPv6) are supported in this mode.
925 This is the default mode, and unless you really know you need another mode, don't change it.
929 In this mode the MAC addresses of the packets on the VPN will be used to
930 dynamically create a routing table just like an Ethernet switch does.
931 Unicast, multicast and broadcast packets of every protocol that runs over Ethernet are supported in this mode
932 at the cost of frequent broadcast ARP requests and routing table updates.
934 This mode is primarily useful if you want to bridge Ethernet segments.
938 This mode is almost the same as the switch mode, but instead
939 every packet will be broadcast to the other daemons
940 while no routing table is managed.
944 @item KeyExpire = <@var{seconds}> (3600)
945 This option controls the time the encryption keys used to encrypt the data
946 are valid. It is common practice to change keys at regular intervals to
947 make it even harder for crackers, even though it is thought to be nearly
948 impossible to crack a single key.
951 @item MACExpire = <@var{seconds}> (600)
952 This option controls the amount of time MAC addresses are kept before they are removed.
953 This only has effect when Mode is set to "switch".
956 @item Name = <@var{name}> [required]
957 This is a symbolic name for this connection. It can be anything
960 @item PingInterval = <@var{seconds}> (60)
961 The number of seconds of inactivity that tinc will wait before sending a
962 probe to the other end.
965 @item PingTimeout = <@var{seconds}> (5)
966 The number of seconds to wait for a response to pings or to allow meta
967 connections to block. If the other end doesn't respond within this time,
968 the connection is terminated, and the others will be notified of this.
970 @cindex PriorityInheritance
971 @item PriorityInheritance = <yes|no> (no) [experimental]
972 When this option is enabled the value of the TOS field of tunneled IPv4 packets
973 will be inherited by the UDP packets that are sent out.
976 @item PrivateKey = <@var{key}> [obsolete]
977 This is the RSA private key for tinc. However, for safety reasons it is
978 advised to store private keys of any kind in separate files. This prevents
979 accidental eavesdropping if you are editting the configuration file.
981 @cindex PrivateKeyFile
982 @item PrivateKeyFile = <@var{path}> (@file{@value{sysconfdir}/tinc/@var{netname}/rsa_key.priv})
983 This is the full path name of the RSA private key file that was
984 generated by @samp{tincd --generate-keys}. It must be a full path, not a
987 Note that there must be exactly one of PrivateKey
989 specified in the configuration file.
992 @item TunnelServer = <yes|no> (no) [experimental]
993 When this option is enabled tinc will no longer forward information between other tinc daemons,
994 and will only allow nodes and subnets on the VPN which are present in the
995 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
1000 @c ==================================================================
1001 @node Host configuration variables
1002 @subsection Host configuration variables
1006 @item Address = <@var{IP address}|@var{hostname}> [recommended]
1007 This variable is only required if you want to connect to this host. It
1008 must resolve to the external IP address where the host can be reached,
1009 not the one that is internal to the VPN.
1012 @item Cipher = <@var{cipher}> (blowfish)
1013 The symmetric cipher algorithm used to encrypt UDP packets.
1014 Any cipher supported by OpenSSL is recognized.
1015 Furthermore, specifying "none" will turn off packet encryption.
1016 It is best to use only those ciphers which support CBC mode.
1019 @item Compression = <@var{level}> (0)
1020 This option sets the level of compression used for UDP packets.
1021 Possible values are 0 (off), 1 (fast zlib) and any integer up to 9 (best zlib),
1022 10 (fast lzo) and 11 (best lzo).
1025 @item Digest = <@var{digest}> (sha1)
1026 The digest algorithm used to authenticate UDP packets.
1027 Any digest supported by OpenSSL is recognized.
1028 Furthermore, specifying "none" will turn off packet authentication.
1030 @cindex IndirectData
1031 @item IndirectData = <yes|no> (no)
1032 This option specifies whether other tinc daemons besides the one you
1033 specified with ConnectTo can make a direct connection to you. This is
1034 especially useful if you are behind a firewall and it is impossible to
1035 make a connection from the outside to your tinc daemon. Otherwise, it
1036 is best to leave this option out or set it to no.
1039 @item MACLength = <@var{bytes}> (4)
1040 The length of the message authentication code used to authenticate UDP packets.
1041 Can be anything from 0
1042 up to the length of the digest produced by the digest algorithm.
1045 @item Port = <@var{port}> (655)
1046 This is the port this tinc daemon listens on.
1047 You can use decimal portnumbers or symbolic names (as listed in @file{/etc/services}).
1050 @item PublicKey = <@var{key}> [obsolete]
1051 This is the RSA public key for this host.
1053 @cindex PublicKeyFile
1054 @item PublicKeyFile = <@var{path}> [obsolete]
1055 This is the full path name of the RSA public key file that was generated
1056 by @samp{tincd --generate-keys}. It must be a full path, not a relative
1060 From version 1.0pre4 on tinc will store the public key directly into the
1061 host configuration file in PEM format, the above two options then are not
1062 necessary. Either the PEM format is used, or exactly
1063 @strong{one of the above two options} must be specified
1064 in each host configuration file, if you want to be able to establish a
1065 connection with that host.
1068 @item Subnet = <@var{address}[/@var{prefixlength}]>
1069 The subnet which this tinc daemon will serve.
1070 Tinc tries to look up which other daemon it should send a packet to by searching the appropiate subnet.
1071 If the packet matches a subnet,
1072 it will be sent to the daemon who has this subnet in his host configuration file.
1073 Multiple subnet lines can be specified for each daemon.
1075 Subnets can either be single MAC, IPv4 or IPv6 addresses,
1076 in which case a subnet consisting of only that single address is assumed,
1077 or they can be a IPv4 or IPv6 network address with a prefixlength.
1078 Shorthand notations are not supported.
1079 For example, IPv4 subnets must be in a form like 192.168.1.0/24,
1080 where 192.168.1.0 is the network address and 24 is the number of bits set in the netmask.
1081 Note that subnets like 192.168.1.1/24 are invalid!
1082 Read a networking HOWTO/FAQ/guide if you don't understand this.
1083 IPv6 subnets are notated like fec0:0:0:1:0:0:0:0/64.
1084 MAC addresses are notated like 0:1a:2b:3c:4d:5e.
1086 @cindex CIDR notation
1087 Prefixlength is the number of bits set to 1 in the netmask part; for
1088 example: netmask 255.255.255.0 would become /24, 255.255.252.0 becomes
1089 /22. This conforms to standard CIDR notation as described in
1090 @uref{ftp://ftp.isi.edu/in-notes/rfc1519.txt, RFC1519}
1093 @item TCPonly = <yes|no> (no) [experimental]
1094 If this variable is set to yes, then the packets are tunnelled over a
1095 TCP connection instead of a UDP connection. This is especially useful
1096 for those who want to run a tinc daemon from behind a masquerading
1097 firewall, or if UDP packet routing is disabled somehow.
1098 Setting this options also implicitly sets IndirectData.
1102 @c ==================================================================
1107 Apart from reading the server and host configuration files,
1108 tinc can also run scripts at certain moments.
1109 Under Windows (not Cygwin), the scripts should have the extension .bat.
1113 @item @value{sysconfdir}/tinc/@var{netname}/tinc-up
1114 This is the most important script.
1115 If it is present it will be executed right after the tinc daemon has been
1116 started and has connected to the virtual network device.
1117 It should be used to set up the corresponding network interface,
1118 but can also be used to start other things.
1119 Under Windows you can use the Network Connections control panel instead of creating this script.
1122 @item @value{sysconfdir}/tinc/@var{netname}/tinc-down
1123 This script is started right before the tinc daemon quits.
1125 @item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-up
1126 This script is started when the tinc daemon with name @var{host} becomes reachable.
1128 @item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-down
1129 This script is started when the tinc daemon with name @var{host} becomes unreachable.
1131 @item @value{sysconfdir}/tinc/@var{netname}/host-up
1132 This script is started when any host becomes reachable.
1134 @item @value{sysconfdir}/tinc/@var{netname}/host-down
1135 This script is started when any host becomes unreachable.
1137 @item @value{sysconfdir}/tinc/@var{netname}/subnet-up
1138 This script is started when a Subnet becomes reachable.
1139 The Subnet and the node it belongs to are passed in environment variables.
1141 @item @value{sysconfdir}/tinc/@var{netname}/subnet-down
1142 This script is started when a Subnet becomes unreachable.
1145 @cindex environment variables
1146 The scripts are started without command line arguments,
1147 but can make use of certain environment variables.
1148 Under UNIX like operating systems the names of environment variables must be preceded by a $ in scripts.
1149 Under Windows, in @file{.bat} files, they have to be put between % signs.
1154 If a netname was specified, this environment variable contains it.
1158 Contains the name of this tinc daemon.
1162 Contains the name of the virtual network device that tinc uses.
1166 Contains the name of the virtual network interface that tinc uses.
1167 This should be used for commands like ifconfig.
1171 When a host becomes (un)reachable, this is set to its name.
1172 If a subnet becomes (un)reachable, this is set to the owner of that subnet.
1174 @cindex REMOTEADDRESS
1176 When a host becomes (un)reachable, this is set to its real address.
1180 When a host becomes (un)reachable,
1181 this is set to the port number it uses for communication with other tinc daemons.
1185 When a subnet becomes (un)reachable, this is set to the subnet.
1190 @c ==================================================================
1191 @node How to configure
1192 @subsection How to configure
1194 @subsubheading Step 1. Creating the main configuration file
1196 The main configuration file will be called @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf}.
1197 Adapt the following example to create a basic configuration file:
1200 Name = @var{yourname}
1201 Device = @file{/dev/tap0}
1204 Then, if you know to which other tinc daemon(s) yours is going to connect,
1205 add `ConnectTo' values.
1207 @subsubheading Step 2. Creating your host configuration file
1209 If you added a line containing `Name = yourname' in the main configuarion file,
1210 you will need to create a host configuration file @file{@value{sysconfdir}/tinc/@var{netname}/hosts/yourname}.
1211 Adapt the following example to create a host configuration file:
1214 Address = your.real.hostname.org
1215 Subnet = 192.168.1.0/24
1218 You can also use an IP address instead of a hostname.
1219 The `Subnet' specifies the address range that is local for @emph{your part of the VPN only}.
1220 If you have multiple address ranges you can specify more than one `Subnet'.
1221 You might also need to add a `Port' if you want your tinc daemon to run on a different port number than the default (655).
1224 @c ==================================================================
1225 @node Generating keypairs
1226 @section Generating keypairs
1228 @cindex key generation
1229 Now that you have already created the main configuration file and your host configuration file,
1230 you can easily create a public/private keypair by entering the following command:
1233 tincd -n @var{netname} -K
1236 Tinc will generate a public and a private key and ask you where to put them.
1237 Just press enter to accept the defaults.
1240 @c ==================================================================
1241 @node Network interfaces
1242 @section Network interfaces
1244 Before tinc can start transmitting data over the tunnel, it must
1245 set up the virtual network interface.
1247 First, decide which IP addresses you want to have associated with these
1248 devices, and what network mask they must have.
1250 Tinc will open a virtual network device (@file{/dev/tun}, @file{/dev/tap0} or similar),
1251 which will also create a network interface called something like @samp{tun0}, @samp{tap0}.
1252 If you are using the Linux tun/tap driver, the network interface will by default have the same name as the @var{netname}.
1253 Under Windows you can change the name of the network interface from the Network Connections control panel.
1256 You can configure the network interface by putting ordinary ifconfig, route, and other commands
1257 to a script named @file{@value{sysconfdir}/tinc/@var{netname}/tinc-up}.
1258 When tinc starts, this script will be executed. When tinc exits, it will execute the script named
1259 @file{@value{sysconfdir}/tinc/@var{netname}/tinc-down}, but normally you don't need to create that script.
1261 An example @file{tinc-up} script:
1265 ifconfig $INTERFACE 192.168.1.1 netmask 255.255.0.0
1268 This script gives the interface an IP address and a netmask.
1269 The kernel will also automatically add a route to this interface, so normally you don't need
1270 to add route commands to the @file{tinc-up} script.
1271 The kernel will also bring the interface up after this command.
1273 The netmask is the mask of the @emph{entire} VPN network, not just your
1276 The exact syntax of the ifconfig and route commands differs from platform to platform.
1277 You can look up the commands for setting addresses and adding routes in @ref{Platform specific information},
1278 but it is best to consult the manpages of those utilities on your platform.
1281 @c ==================================================================
1282 @node Example configuration
1283 @section Example configuration
1287 Imagine the following situation. Branch A of our example `company' wants to connect
1288 three branch offices in B, C and D using the Internet. All four offices
1289 have a 24/7 connection to the Internet.
1291 A is going to serve as the center of the network. B and C will connect
1292 to A, and D will connect to C. Each office will be assigned their own IP
1296 A: net 10.1.0.0 mask 255.255.0.0 gateway 10.1.54.1 internet IP 1.2.3.4
1297 B: net 10.2.0.0 mask 255.255.0.0 gateway 10.2.1.12 internet IP 2.3.4.5
1298 C: net 10.3.0.0 mask 255.255.0.0 gateway 10.3.69.254 internet IP 3.4.5.6
1299 D: net 10.4.0.0 mask 255.255.0.0 gateway 10.4.3.32 internet IP 4.5.6.7
1302 Here, ``gateway'' is the VPN IP address of the machine that is running the
1303 tincd, and ``internet IP'' is the IP address of the firewall, which does not
1304 need to run tincd, but it must do a port forwarding of TCP and UDP on port
1305 655 (unless otherwise configured).
1307 In this example, it is assumed that eth0 is the interface that points to
1308 the inner (physical) LAN of the office, although this could also be the
1309 same as the interface that leads to the Internet. The configuration of
1310 the real interface is also shown as a comment, to give you an idea of
1311 how these example host is set up. All branches use the netname `company'
1312 for this particular VPN.
1314 @subsubheading For Branch A
1316 @emph{BranchA} would be configured like this:
1318 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1321 # Real interface of internal network:
1322 # ifconfig eth0 10.1.54.1 netmask 255.255.0.0
1324 ifconfig $INTERFACE 10.1.54.1 netmask 255.0.0.0
1327 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1334 On all hosts, @file{@value{sysconfdir}/tinc/company/hosts/BranchA} contains:
1337 Subnet = 10.1.0.0/16
1340 -----BEGIN RSA PUBLIC KEY-----
1342 -----END RSA PUBLIC KEY-----
1345 Note that the IP addresses of eth0 and tap0 are the same.
1346 This is quite possible, if you make sure that the netmasks of the interfaces are different.
1347 It is in fact recommended to give give both real internal network interfaces and tap interfaces the same IP address,
1348 since that will make things a lot easier to remember and set up.
1351 @subsubheading For Branch B
1353 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1356 # Real interface of internal network:
1357 # ifconfig eth0 10.2.43.8 netmask 255.255.0.0
1359 ifconfig $INTERFACE 10.2.1.12 netmask 255.0.0.0
1362 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1369 Note here that the internal address (on eth0) doesn't have to be the
1370 same as on the tap0 device. Also, ConnectTo is given so that no-one can
1371 connect to this node.
1373 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchB}:
1376 Subnet = 10.2.0.0/16
1379 -----BEGIN RSA PUBLIC KEY-----
1381 -----END RSA PUBLIC KEY-----
1385 @subsubheading For Branch C
1387 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1390 # Real interface of internal network:
1391 # ifconfig eth0 10.3.69.254 netmask 255.255.0.0
1393 ifconfig $INTERFACE 10.3.69.254 netmask 255.0.0.0
1396 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1404 C already has another daemon that runs on port 655, so they have to
1405 reserve another port for tinc. It knows the portnumber it has to listen on
1406 from it's own host configuration file.
1408 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchC}:
1412 Subnet = 10.3.0.0/16
1415 -----BEGIN RSA PUBLIC KEY-----
1417 -----END RSA PUBLIC KEY-----
1421 @subsubheading For Branch D
1423 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1426 # Real interface of internal network:
1427 # ifconfig eth0 10.4.3.32 netmask 255.255.0.0
1429 ifconfig $INTERFACE 10.4.3.32 netmask 255.0.0.0
1432 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1437 Device = /dev/net/tun
1440 D will be connecting to C, which has a tincd running for this network on
1441 port 2000. It knows the port number from the host configuration file.
1442 Also note that since D uses the tun/tap driver, the network interface
1443 will not be called `tun' or `tap0' or something like that, but will
1444 have the same name as netname.
1446 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchD}:
1449 Subnet = 10.4.0.0/16
1452 -----BEGIN RSA PUBLIC KEY-----
1454 -----END RSA PUBLIC KEY-----
1457 @subsubheading Key files
1459 A, B, C and D all have generated a public/private keypair with the following command:
1465 The private key is stored in @file{@value{sysconfdir}/tinc/company/rsa_key.priv},
1466 the public key is put into the host configuration file in the @file{@value{sysconfdir}/tinc/company/hosts/} directory.
1467 During key generation, tinc automatically guesses the right filenames based on the -n option and
1468 the Name directive in the @file{tinc.conf} file (if it is available).
1470 @subsubheading Starting
1472 After each branch has finished configuration and they have distributed
1473 the host configuration files amongst them, they can start their tinc daemons.
1474 They don't necessarily have to wait for the other branches to have started
1475 their daemons, tinc will try connecting until they are available.
1478 @c ==================================================================
1480 @chapter Running tinc
1482 If everything else is done, you can start tinc by typing the following command:
1485 tincd -n @var{netname}
1489 Tinc will detach from the terminal and continue to run in the background like a good daemon.
1490 If there are any problems however you can try to increase the debug level
1491 and look in the syslog to find out what the problems are.
1497 * Solving problems::
1499 * Sending bug reports::
1503 @c ==================================================================
1504 @node Runtime options
1505 @section Runtime options
1507 Besides the settings in the configuration file, tinc also accepts some
1508 command line options.
1510 @cindex command line
1511 @cindex runtime options
1515 @item -c, --config=@var{path}
1516 Read configuration options from the directory @var{path}. The default is
1517 @file{@value{sysconfdir}/tinc/@var{netname}/}.
1519 @item -D, --no-detach
1520 Don't fork and detach.
1521 This will also disable the automatic restart mechanism for fatal errors.
1524 @item -d, --debug=@var{level}
1525 Set debug level to @var{level}. The higher the debug level, the more gets
1526 logged. Everything goes via syslog.
1528 @item -k, --kill[=@var{signal}]
1529 Attempt to kill a running tincd (optionally with the specified @var{signal} instead of SIGTERM) and exit.
1530 Use it in conjunction with the -n option to make sure you kill the right tinc daemon.
1531 Under native Windows the optional argument is ignored,
1532 the service will always be stopped and removed.
1534 @item -n, --net=@var{netname}
1535 Use configuration for net @var{netname}. @xref{Multiple networks}.
1537 @item -K, --generate-keys[=@var{bits}]
1538 Generate public/private keypair of @var{bits} length. If @var{bits} is not specified,
1539 1024 is the default. tinc will ask where you want to store the files,
1540 but will default to the configuration directory (you can use the -c or -n option
1541 in combination with -K). After that, tinc will quit.
1544 Lock tinc into main memory.
1545 This will prevent sensitive data like shared private keys to be written to the system swap files/partitions.
1547 @item --logfile[=@var{file}]
1548 Write log entries to a file instead of to the system logging facility.
1549 If @var{file} is omitted, the default is @file{@value{localstatedir}/log/tinc.@var{netname}.log}.
1551 @item --pidfile=@var{file}
1552 Write PID to @var{file} instead of @file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
1554 @item --bypass-security
1555 Disables encryption and authentication.
1556 Only useful for debugging.
1559 Display a short reminder of these runtime options and terminate.
1562 Output version information and exit.
1566 @c ==================================================================
1571 You can also send the following signals to a running tincd process:
1577 Forces tinc to try to connect to all uplinks immediately.
1578 Usually tinc attempts to do this itself,
1579 but increases the time it waits between the attempts each time it failed,
1580 and if tinc didn't succeed to connect to an uplink the first time after it started,
1581 it defaults to the maximum time of 15 minutes.
1584 Partially rereads configuration files.
1585 Connections to hosts whose host config file are removed are closed.
1586 New outgoing connections specified in @file{tinc.conf} will be made.
1589 Temporarily increases debug level to 5.
1590 Send this signal again to revert to the original level.
1593 Dumps the connection list to syslog.
1596 Dumps virtual network device statistics, all known nodes, edges and subnets to syslog.
1599 Purges all information remembered about unreachable nodes.
1603 @c ==================================================================
1605 @section Debug levels
1607 @cindex debug levels
1608 The tinc daemon can send a lot of messages to the syslog.
1609 The higher the debug level, the more messages it will log.
1610 Each level inherits all messages of the previous level:
1616 This will log a message indicating tinc has started along with a version number.
1617 It will also log any serious error.
1620 This will log all connections that are made with other tinc daemons.
1623 This will log status and error messages from scripts and other tinc daemons.
1626 This will log all requests that are exchanged with other tinc daemons. These include
1627 authentication, key exchange and connection list updates.
1630 This will log a copy of everything received on the meta socket.
1633 This will log all network traffic over the virtual private network.
1637 @c ==================================================================
1638 @node Solving problems
1639 @section Solving problems
1641 If tinc starts without problems, but if the VPN doesn't work, you will have to find the cause of the problem.
1642 The first thing to do is to start tinc with a high debug level in the foreground,
1643 so you can directly see everything tinc logs:
1646 tincd -n @var{netname} -d5 -D
1649 If tinc does not log any error messages, then you might want to check the following things:
1652 @item @file{tinc-up} script
1653 Does this script contain the right commands?
1654 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.
1657 Does the Subnet (or Subnets) in the host configuration file of this host match the portion of the VPN that belongs to this host?
1659 @item Firewalls and NATs
1660 Do you have a firewall or a NAT device (a masquerading firewall or perhaps an ADSL router that performs masquerading)?
1661 If so, check that it allows TCP and UDP traffic on port 655.
1662 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.
1663 You can add @samp{TCPOnly = yes} to your host config file to force tinc to only use a single TCP connection,
1664 this works through most firewalls and NATs.
1669 @c ==================================================================
1670 @node Error messages
1671 @section Error messages
1673 What follows is a list of the most common error messages you might find in the logs.
1674 Some of them will only be visible if the debug level is high enough.
1677 @item Could not open /dev/tap0: No such device
1680 @item You forgot to `modprobe netlink_dev' or `modprobe ethertap'.
1681 @item You forgot to compile `Netlink device emulation' in the kernel.
1684 @item Can't write to /dev/net/tun: No such device
1687 @item You forgot to `modprobe tun'.
1688 @item You forgot to compile `Universal TUN/TAP driver' in the kernel.
1689 @item The tun device is located somewhere else in @file{/dev/}.
1692 @item Network address and prefix length do not match!
1695 @item The Subnet field must contain a @emph{network} address, trailing bits should be 0.
1696 @item If you only want to use one IP address, set the netmask to /32.
1699 @item Error reading RSA key file `rsa_key.priv': No such file or directory
1702 @item You forgot to create a public/private keypair.
1703 @item Specify the complete pathname to the private key file with the @samp{PrivateKeyFile} option.
1706 @item Warning: insecure file permissions for RSA private key file `rsa_key.priv'!
1709 @item The private key file is readable by users other than root.
1710 Use chmod to correct the file permissions.
1713 @item Creating metasocket failed: Address family not supported
1716 @item By default tinc tries to create both IPv4 and IPv6 sockets.
1717 On some platforms this might not be implemented.
1718 If the logs show @samp{Ready} later on, then at least one metasocket was created,
1719 and you can ignore this message.
1720 You can add @samp{AddressFamily = ipv4} to @file{tinc.conf} to prevent this from happening.
1723 @item Cannot route packet: unknown IPv4 destination 1.2.3.4
1726 @item You try to send traffic to a host on the VPN for which no Subnet is known.
1727 @item If it is a broadcast address (ending in .255), it probably is a samba server or a Windows host sending broadcast packets.
1731 @item Cannot route packet: ARP request for unknown address 1.2.3.4
1734 @item You try to send traffic to a host on the VPN for which no Subnet is known.
1737 @item Packet with destination 1.2.3.4 is looping back to us!
1740 @item Something is not configured right. Packets are being sent out to the
1741 virtual network device, but according to the Subnet directives in your host configuration
1742 file, those packets should go to your own host. Most common mistake is that
1743 you have a Subnet line in your host configuration file with a prefix length which is
1744 just as large as the prefix of the virtual network interface. The latter should in almost all
1745 cases be larger. Rethink your configuration.
1746 Note that you will only see this message if you specified a debug
1747 level of 5 or higher!
1748 @item Chances are that a @samp{Subnet = ...} line in the host configuration file of this tinc daemon is wrong.
1749 Change it to a subnet that is accepted locally by another interface,
1750 or if that is not the case, try changing the prefix length into /32.
1753 @item Node foo (1.2.3.4) is not reachable
1756 @item Node foo does not have a connection anymore, its tinc daemon is not running or its connection to the Internet is broken.
1759 @item Received UDP packet from unknown source 1.2.3.4 (port 12345)
1762 @item If you see this only sporadically, it is harmless and caused by a node sending packets using an old key.
1763 @item If you see this often and another node is not reachable anymore, then a NAT (masquerading firewall) is changing the source address of UDP packets.
1764 You can add @samp{TCPOnly = yes} to host configuration files to force all VPN traffic to go over a TCP connection.
1767 @item Got bad/bogus/unauthorized REQUEST from foo (1.2.3.4 port 12345)
1770 @item Node foo does not have the right public/private keypair.
1771 Generate new keypairs and distribute them again.
1772 @item An attacker tries to gain access to your VPN.
1773 @item A network error caused corruption of metadata sent from foo.
1778 @c ==================================================================
1779 @node Sending bug reports
1780 @section Sending bug reports
1782 If you really can't find the cause of a problem, or if you suspect tinc is not working right,
1783 you can send us a bugreport, see @ref{Contact information}.
1784 Be sure to include the following information in your bugreport:
1787 @item A clear description of what you are trying to achieve and what the problem is.
1788 @item What platform (operating system, version, hardware architecture) and which version of tinc you use.
1789 @item If compiling tinc fails, a copy of @file{config.log} and the error messages you get.
1790 @item Otherwise, a copy of @file{tinc.conf}, @file{tinc-up} and all files in the @file{hosts/} directory.
1791 @item The output of the commands @samp{ifconfig -a} and @samp{route -n} (or @samp{netstat -rn} if that doesn't work).
1792 @item The output of any command that fails to work as it should (like ping or traceroute).
1795 @c ==================================================================
1796 @node Technical information
1797 @chapter Technical information
1802 * The meta-protocol::
1807 @c ==================================================================
1808 @node The connection
1809 @section The connection
1812 Tinc is a daemon that takes VPN data and transmit that to another host
1813 computer over the existing Internet infrastructure.
1817 * The meta-connection::
1821 @c ==================================================================
1822 @node The UDP tunnel
1823 @subsection The UDP tunnel
1825 @cindex virtual network device
1827 The data itself is read from a character device file, the so-called
1828 @emph{virtual network device}. This device is associated with a network
1829 interface. Any data sent to this interface can be read from the device,
1830 and any data written to the device gets sent from the interface.
1831 There are two possible types of virtual network devices:
1832 `tun' style, which are point-to-point devices which can only handle IPv4 and/or IPv6 packets,
1833 and `tap' style, which are Ethernet devices and handle complete Ethernet frames.
1835 So when tinc reads an Ethernet frame from the device, it determines its
1836 type. When tinc is in it's default routing mode, it can handle IPv4 and IPv6
1837 packets. Depending on the Subnet lines, it will send the packets off to their destination IP address.
1838 In the `switch' and `hub' mode, tinc will use broadcasts and MAC address discovery
1839 to deduce the destination of the packets.
1840 Since the latter modes only depend on the link layer information,
1841 any protocol that runs over Ethernet is supported (for instance IPX and Appletalk).
1842 However, only `tap' style devices provide this information.
1844 After the destination has been determined,
1845 the packet will be compressed (optionally),
1846 a sequence number will be added to the packet,
1847 the packet will then be encrypted
1848 and a message authentication code will be appended.
1850 @cindex encapsulating
1852 When that is done, time has come to actually transport the
1853 packet to the destination computer. We do this by sending the packet
1854 over an UDP connection to the destination host. This is called
1855 @emph{encapsulating}, the VPN packet (though now encrypted) is
1856 encapsulated in another IP datagram.
1858 When the destination receives this packet, the same thing happens, only
1859 in reverse. So it checks the message authentication code, decrypts the contents of the UDP datagram,
1860 checks the sequence number
1861 and writes the decrypted information to its own virtual network device.
1863 If the virtual network device is a `tun' device (a point-to-point tunnel),
1864 there is no problem for the kernel to accept a packet.
1865 However, if it is a `tap' device (this is the only available type on FreeBSD),
1866 the destination MAC address must match that of the virtual network interface.
1867 If tinc is in it's default routing mode, ARP does not work, so the correct destination MAC
1868 can not be known by the sending host.
1869 Tinc solves this by letting the receiving end detect the MAC address of its own virtual network interface
1870 and overwriting the destination MAC address of the received packet.
1872 In switch or hub modes ARP does work so the sender already knows the correct destination MAC address.
1873 In those modes every interface should have a unique MAC address, so make sure they are not the same.
1874 Because switch and hub modes rely on MAC addresses to function correctly,
1875 these modes cannot be used on the following operating systems which don't have a `tap' style virtual network device:
1876 OpenBSD, NetBSD, Darwin and Solaris.
1879 @c ==================================================================
1880 @node The meta-connection
1881 @subsection The meta-connection
1883 Having only a UDP connection available is not enough. Though suitable
1884 for transmitting data, we want to be able to reliably send other
1885 information, such as routing and session key information to somebody.
1888 TCP is a better alternative, because it already contains protection
1889 against information being lost, unlike UDP.
1891 So we establish two connections. One for the encrypted VPN data, and one
1892 for other information, the meta-data. Hence, we call the second
1893 connection the meta-connection. We can now be sure that the
1894 meta-information doesn't get lost on the way to another computer.
1896 @cindex data-protocol
1897 @cindex meta-protocol
1898 Like with any communication, we must have a protocol, so that everybody
1899 knows what everything stands for, and how she should react. Because we
1900 have two connections, we also have two protocols. The protocol used for
1901 the UDP data is the ``data-protocol,'' the other one is the
1904 The reason we don't use TCP for both protocols is that UDP is much
1905 better for encapsulation, even while it is less reliable. The real
1906 problem is that when TCP would be used to encapsulate a TCP stream
1907 that's on the private network, for every packet sent there would be
1908 three ACKs sent instead of just one. Furthermore, if there would be
1909 a timeout, both TCP streams would sense the timeout, and both would
1910 start re-sending packets.
1913 @c ==================================================================
1914 @node The meta-protocol
1915 @section The meta-protocol
1917 The meta protocol is used to tie all tinc daemons together, and
1918 exchange information about which tinc daemon serves which virtual
1921 The meta protocol consists of requests that can be sent to the other
1922 side. Each request has a unique number and several parameters. All
1923 requests are represented in the standard ASCII character set. It is
1924 possible to use tools such as telnet or netcat to connect to a tinc
1925 daemon started with the --bypass-security option
1926 and to read and write requests by hand, provided that one
1927 understands the numeric codes sent.
1929 The authentication scheme is described in @ref{Authentication protocol}. After a
1930 successful authentication, the server and the client will exchange all the
1931 information about other tinc daemons and subnets they know of, so that both
1932 sides (and all the other tinc daemons behind them) have their information
1939 ------------------------------------------------------------------
1940 ADD_EDGE node1 node2 21.32.43.54 655 222 0
1941 | | | | | +-> options
1942 | | | | +----> weight
1943 | | | +--------> UDP port of node2
1944 | | +----------------> real address of node2
1945 | +-------------------------> name of destination node
1946 +-------------------------------> name of source node
1948 ADD_SUBNET node 192.168.1.0/24
1949 | | +--> prefixlength
1950 | +--------> network address
1951 +------------------> owner of this subnet
1952 ------------------------------------------------------------------
1955 The ADD_EDGE messages are to inform other tinc daemons that a connection between
1956 two nodes exist. The address of the destination node is available so that
1957 VPN packets can be sent directly to that node.
1959 The ADD_SUBNET messages inform other tinc daemons that certain subnets belong
1960 to certain nodes. tinc will use it to determine to which node a VPN packet has
1967 ------------------------------------------------------------------
1968 DEL_EDGE node1 node2
1969 | +----> name of destination node
1970 +----------> name of source node
1972 DEL_SUBNET node 192.168.1.0/24
1973 | | +--> prefixlength
1974 | +--------> network address
1975 +------------------> owner of this subnet
1976 ------------------------------------------------------------------
1979 In case a connection between two daemons is closed or broken, DEL_EDGE messages
1980 are sent to inform the other daemons of that fact. Each daemon will calculate a
1981 new route to the the daemons, or mark them unreachable if there isn't any.
1988 ------------------------------------------------------------------
1989 REQ_KEY origin destination
1990 | +--> name of the tinc daemon it wants the key from
1991 +----------> name of the daemon that wants the key
1993 ANS_KEY origin destination 4ae0b0a82d6e0078 91 64 4
1994 | | \______________/ | | +--> MAC length
1995 | | | | +-----> digest algorithm
1996 | | | +--------> cipher algorithm
1997 | | +--> 128 bits key
1998 | +--> name of the daemon that wants the key
1999 +----------> name of the daemon that uses this key
2002 +--> daemon that has changed it's packet key
2003 ------------------------------------------------------------------
2006 The keys used to encrypt VPN packets are not sent out directly. This is
2007 because it would generate a lot of traffic on VPNs with many daemons, and
2008 chances are that not every tinc daemon will ever send a packet to every
2009 other daemon. Instead, if a daemon needs a key it sends a request for it
2010 via the meta connection of the nearest hop in the direction of the
2017 ------------------------------------------------------------------
2020 ------------------------------------------------------------------
2023 There is also a mechanism to check if hosts are still alive. Since network
2024 failures or a crash can cause a daemon to be killed without properly
2025 shutting down the TCP connection, this is necessary to keep an up to date
2026 connection list. PINGs are sent at regular intervals, except when there
2027 is also some other traffic. A little bit of salt (random data) is added
2028 with each PING and PONG message, to make sure that long sequences of PING/PONG
2029 messages without any other traffic won't result in known plaintext.
2031 This basically covers what is sent over the meta connection by tinc.
2034 @c ==================================================================
2040 Tinc got its name from ``TINC,'' short for @emph{There Is No Cabal}; the
2041 alleged Cabal was/is an organisation that was said to keep an eye on the
2042 entire Internet. As this is exactly what you @emph{don't} want, we named
2043 the tinc project after TINC.
2046 But in order to be ``immune'' to eavesdropping, you'll have to encrypt
2047 your data. Because tinc is a @emph{Secure} VPN (SVPN) daemon, it does
2048 exactly that: encrypt.
2049 Tinc by default uses blowfish encryption with 128 bit keys in CBC mode, 32 bit
2050 sequence numbers and 4 byte long message authentication codes to make sure
2051 eavesdroppers cannot get and cannot change any information at all from the
2052 packets they can intercept. The encryption algorithm and message authentication
2053 algorithm can be changed in the configuration. The length of the message
2054 authentication codes is also adjustable. The length of the key for the
2055 encryption algorithm is always the default length used by OpenSSL.
2058 * Authentication protocol::
2059 * Encryption of network packets::
2064 @c ==================================================================
2065 @node Authentication protocol
2066 @subsection Authentication protocol
2068 @cindex authentication
2069 A new scheme for authentication in tinc has been devised, which offers some
2070 improvements over the protocol used in 1.0pre2 and 1.0pre3. Explanation is
2080 --------------------------------------------------------------------------
2081 client <attempts connection>
2083 server <accepts connection>
2087 +-------> name of tinc daemon
2091 +-------> name of tinc daemon
2093 client META_KEY 5f0823a93e35b69e...7086ec7866ce582b
2094 \_________________________________/
2095 +-> RSAKEYLEN bits totally random string S1,
2096 encrypted with server's public RSA key
2098 server META_KEY 6ab9c1640388f8f0...45d1a07f8a672630
2099 \_________________________________/
2100 +-> RSAKEYLEN bits totally random string S2,
2101 encrypted with client's public RSA key
2104 - the client will symmetrically encrypt outgoing traffic using S1
2105 - the server will symmetrically encrypt outgoing traffic using S2
2107 client CHALLENGE da02add1817c1920989ba6ae2a49cecbda0
2108 \_________________________________/
2109 +-> CHALLEN bits totally random string H1
2111 server CHALLENGE 57fb4b2ccd70d6bb35a64c142f47e61d57f
2112 \_________________________________/
2113 +-> CHALLEN bits totally random string H2
2115 client CHAL_REPLY 816a86
2116 +-> 160 bits SHA1 of H2
2118 server CHAL_REPLY 928ffe
2119 +-> 160 bits SHA1 of H1
2121 After the correct challenge replies are received, both ends have proved
2122 their identity. Further information is exchanged.
2124 client ACK 655 123 0
2126 | +----> estimated weight
2127 +--------> listening port of client
2129 server ACK 655 321 0
2131 | +----> estimated weight
2132 +--------> listening port of server
2133 --------------------------------------------------------------------------
2136 This new scheme has several improvements, both in efficiency and security.
2138 First of all, the server sends exactly the same kind of messages over the wire
2139 as the client. The previous versions of tinc first authenticated the client,
2140 and then the server. This scheme even allows both sides to send their messages
2141 simultaneously, there is no need to wait for the other to send something first.
2142 This means that any calculations that need to be done upon sending or receiving
2143 a message can also be done in parallel. This is especially important when doing
2144 RSA encryption/decryption. Given that these calculations are the main part of
2145 the CPU time spent for the authentication, speed is improved by a factor 2.
2147 Second, only one RSA encrypted message is sent instead of two. This reduces the
2148 amount of information attackers can see (and thus use for a cryptographic
2149 attack). It also improves speed by a factor two, making the total speedup a
2152 Third, and most important:
2153 The symmetric cipher keys are exchanged first, the challenge is done
2154 afterwards. In the previous authentication scheme, because a man-in-the-middle
2155 could pass the challenge/chal_reply phase (by just copying the messages between
2156 the two real tinc daemons), but no information was exchanged that was really
2157 needed to read the rest of the messages, the challenge/chal_reply phase was of
2158 no real use. The man-in-the-middle was only stopped by the fact that only after
2159 the ACK messages were encrypted with the symmetric cipher. Potentially, it
2160 could even send it's own symmetric key to the server (if it knew the server's
2161 public key) and read some of the metadata the server would send it (it was
2162 impossible for the mitm to read actual network packets though). The new scheme
2163 however prevents this.
2165 This new scheme makes sure that first of all, symmetric keys are exchanged. The
2166 rest of the messages are then encrypted with the symmetric cipher. Then, each
2167 side can only read received messages if they have their private key. The
2168 challenge is there to let the other side know that the private key is really
2169 known, because a challenge reply can only be sent back if the challenge is
2170 decrypted correctly, and that can only be done with knowledge of the private
2173 Fourth: the first thing that is sent via the symmetric cipher encrypted
2174 connection is a totally random string, so that there is no known plaintext (for
2175 an attacker) in the beginning of the encrypted stream.
2178 @c ==================================================================
2179 @node Encryption of network packets
2180 @subsection Encryption of network packets
2183 A data packet can only be sent if the encryption key is known to both
2184 parties, and the connection is activated. If the encryption key is not
2185 known, a request is sent to the destination using the meta connection
2186 to retrieve it. The packet is stored in a queue while waiting for the
2190 The UDP packet containing the network packet from the VPN has the following layout:
2193 ... | IP header | UDP header | seqno | VPN packet | MAC | UDP trailer
2194 \___________________/\_____/
2196 V +---> digest algorithm
2197 Encrypted with symmetric cipher
2200 So, the entire VPN packet is encrypted using a symmetric cipher, including a 32 bits
2201 sequence number that is added in front of the actual VPN packet, to act as a unique
2202 IV for each packet and to prevent replay attacks. A message authentication code
2203 is added to the UDP packet to prevent alteration of packets. By default the
2204 first 4 bytes of the digest are used for this, but this can be changed using
2205 the MACLength configuration variable.
2207 @c ==================================================================
2208 @node Security issues
2209 @subsection Security issues
2211 In August 2000, we discovered the existence of a security hole in all versions
2212 of tinc up to and including 1.0pre2. This had to do with the way we exchanged
2213 keys. Since then, we have been working on a new authentication scheme to make
2214 tinc as secure as possible. The current version uses the OpenSSL library and
2215 uses strong authentication with RSA keys.
2217 On the 29th of December 2001, Jerome Etienne posted a security analysis of tinc
2218 1.0pre4. Due to a lack of sequence numbers and a message authentication code
2219 for each packet, an attacker could possibly disrupt certain network services or
2220 launch a denial of service attack by replaying intercepted packets. The current
2221 version adds sequence numbers and message authentication codes to prevent such
2224 On the 15th of September 2003, Peter Gutmann posted a security analysis of tinc
2225 1.0.1. He argues that the 32 bit sequence number used by tinc is not a good IV,
2226 that tinc's default length of 4 bytes for the MAC is too short, and he doesn't
2227 like tinc's use of RSA during authentication. We do not know of a security hole
2228 in this version of tinc, but tinc's security is not as strong as TLS or IPsec.
2229 We will address these issues in tinc 2.0.
2231 Cryptography is a hard thing to get right. We cannot make any
2232 guarantees. Time, review and feedback are the only things that can
2233 prove the security of any cryptographic product. If you wish to review
2234 tinc or give us feedback, you are stronly encouraged to do so.
2237 @c ==================================================================
2238 @node Platform specific information
2239 @chapter Platform specific information
2242 * Interface configuration::
2246 @c ==================================================================
2247 @node Interface configuration
2248 @section Interface configuration
2250 When configuring an interface, one normally assigns it an address and a
2251 netmask. The address uniquely identifies the host on the network attached to
2252 the interface. The netmask, combined with the address, forms a subnet. It is
2253 used to add a route to the routing table instructing the kernel to send all
2254 packets which fall into that subnet to that interface. Because all packets for
2255 the entire VPN should go to the virtual network interface used by tinc, the
2256 netmask should be such that it encompasses the entire VPN.
2260 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2262 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2263 @item Linux iproute2
2264 @tab @code{ip addr add} @var{address}@code{/}@var{prefixlength} @code{dev} @var{interface}
2266 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2268 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2270 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2272 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2273 @item Darwin (MacOS/X)
2274 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2276 @tab @code{netsh interface ip set address} @var{interface} @code{static} @var{address} @var{netmask}
2282 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2284 @tab @code{ifconfig} @var{interface} @code{add} @var{address}@code{/}@var{prefixlength}
2286 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2288 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2290 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2292 @tab @code{ifconfig} @var{interface} @code{inet6 plumb up}
2294 @tab @code{ifconfig} @var{interface} @code{inet6 addif} @var{address} @var{address}
2295 @item Darwin (MacOS/X)
2296 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2298 @tab @code{netsh interface ipv6 add address} @var{interface} @code{static} @var{address}/@var{prefixlength}
2302 @c ==================================================================
2306 In some cases it might be necessary to add more routes to the virtual network
2307 interface. There are two ways to indicate which interface a packet should go
2308 to, one is to use the name of the interface itself, another way is to specify
2309 the (local) address that is assigned to that interface (@var{local_address}). The
2310 former way is unambiguous and therefore preferable, but not all platforms
2313 Adding routes to IPv4 subnets:
2315 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2317 @tab @code{route add -net} @var{network_address} @code{netmask} @var{netmask} @var{interface}
2318 @item Linux iproute2
2319 @tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
2321 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2323 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2325 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2327 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
2328 @item Darwin (MacOS/X)
2329 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2331 @tab @code{netsh routing ip add persistentroute} @var{network_address} @var{netmask} @var{interface} @var{local_address}
2334 Adding routes to IPv6 subnets:
2336 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2338 @tab @code{route add -A inet6} @var{network_address}@code{/}@var{prefixlength} @var{interface}
2339 @item Linux iproute2
2340 @tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
2342 @tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2344 @tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
2346 @tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
2348 @tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
2349 @item Darwin (MacOS/X)
2352 @tab @code{netsh interface ipv6 add route} @var{network address}/@var{prefixlength} @var{interface}
2356 @c ==================================================================
2362 * Contact information::
2367 @c ==================================================================
2368 @node Contact information
2369 @section Contact information
2372 Tinc's website is at @url{http://www.tinc-vpn.org/},
2373 this server is located in the Netherlands.
2376 We have an IRC channel on the FreeNode and OFTC IRC networks. Connect to
2377 @uref{http://www.freenode.net/, irc.freenode.net}
2379 @uref{http://www.oftc.net/, irc.oftc.net}
2380 and join channel #tinc.
2383 @c ==================================================================
2388 @item Ivo Timmermans (zarq) (@email{ivo@@tinc-vpn.org})
2389 @item Guus Sliepen (guus) (@email{guus@@tinc-vpn.org})
2392 We have received a lot of valuable input from users. With their help,
2393 tinc has become the flexible and robust tool that it is today. We have
2394 composed a list of contributions, in the file called @file{THANKS} in
2395 the source distribution.
2398 @c ==================================================================
2400 @unnumbered Concept Index
2402 @c ==================================================================
2406 @c ==================================================================