1 \input texinfo @c -*-texinfo-*-
8 @include tincinclude.texi
11 @dircategory Networking tools
13 * tinc: (tinc). The tinc Manual.
16 This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
18 Copyright @copyright{} 1998-2013 Ivo Timmermans,
19 Guus Sliepen <guus@@tinc-vpn.org> and
20 Wessel Dankers <wsl@@tinc-vpn.org>.
22 Permission is granted to make and distribute verbatim copies of this
23 manual provided the copyright notice and this permission notice are
24 preserved on all copies.
26 Permission is granted to copy and distribute modified versions of this
27 manual under the conditions for verbatim copying, provided that the
28 entire resulting derived work is distributed under the terms of a
29 permission notice identical to this one.
39 @subtitle Setting up a Virtual Private Network with tinc
40 @author Ivo Timmermans and Guus Sliepen
43 @vskip 0pt plus 1filll
44 This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
46 Copyright @copyright{} 1998-2013 Ivo Timmermans,
47 Guus Sliepen <guus@@tinc-vpn.org> and
48 Wessel Dankers <wsl@@tinc-vpn.org>.
50 Permission is granted to make and distribute verbatim copies of this
51 manual provided the copyright notice and this permission notice are
52 preserved on all copies.
54 Permission is granted to copy and distribute modified versions of this
55 manual under the conditions for verbatim copying, provided that the
56 entire resulting derived work is distributed under the terms of a
57 permission notice identical to this one.
62 @c ==================================================================
73 * Technical information::
74 * Platform specific information::
76 * Concept Index:: All used terms explained
80 @c ==================================================================
85 Tinc is a Virtual Private Network (VPN) daemon that uses tunneling and
86 encryption to create a secure private network between hosts on the
89 Because the tunnel appears to the IP level network code as a normal
90 network device, there is no need to adapt any existing software.
91 The encrypted tunnels allows VPN sites to share information with each other
92 over the Internet without exposing any information to others.
94 This document is the manual for tinc. Included are chapters on how to
95 configure your computer to use tinc, as well as the configuration
96 process of tinc itself.
99 * Virtual Private Networks::
101 * Supported platforms::
104 @c ==================================================================
105 @node Virtual Private Networks
106 @section Virtual Private Networks
109 A Virtual Private Network or VPN is a network that can only be accessed
110 by a few elected computers that participate. This goal is achievable in
111 more than just one way.
114 Private networks can consist of a single stand-alone Ethernet LAN. Or
115 even two computers hooked up using a null-modem cable. In these cases,
117 obvious that the network is @emph{private}, no one can access it from the
118 outside. But if your computers are linked to the Internet, the network
119 is not private anymore, unless one uses firewalls to block all private
120 traffic. But then, there is no way to send private data to trusted
121 computers on the other end of the Internet.
124 This problem can be solved by using @emph{virtual} networks. Virtual
125 networks can live on top of other networks, but they use encapsulation to
126 keep using their private address space so they do not interfere with
127 the Internet. Mostly, virtual networks appear like a single LAN, even though
128 they can span the entire world. But virtual networks can't be secured
129 by using firewalls, because the traffic that flows through it has to go
130 through the Internet, where other people can look at it.
132 As is the case with either type of VPN, anybody could eavesdrop. Or
133 worse, alter data. Hence it's probably advisable to encrypt the data
134 that flows over the network.
136 When one introduces encryption, we can form a true VPN. Other people may
137 see encrypted traffic, but if they don't know how to decipher it (they
138 need to know the key for that), they cannot read the information that flows
139 through the VPN. This is what tinc was made for.
142 @c ==================================================================
147 I really don't quite remember what got us started, but it must have been
148 Guus' idea. He wrote a simple implementation (about 50 lines of C) that
149 used the ethertap device that Linux knows of since somewhere
150 about kernel 2.1.60. It didn't work immediately and he improved it a
151 bit. At this stage, the project was still simply called "vpnd".
153 Since then, a lot has changed---to say the least.
156 Tinc now supports encryption, it consists of a single daemon (tincd) for
157 both the receiving and sending end, it has become largely
158 runtime-configurable---in short, it has become a full-fledged
159 professional package.
161 @cindex traditional VPNs
163 Tinc also allows more than two sites to connect to eachother and form a single VPN.
164 Traditionally VPNs are created by making tunnels, which only have two endpoints.
165 Larger VPNs with more sites are created by adding more tunnels.
166 Tinc takes another approach: only endpoints are specified,
167 the software itself will take care of creating the tunnels.
168 This allows for easier configuration and improved scalability.
170 A lot can---and will be---changed. We have a number of things that we would like to
171 see in the future releases of tinc. Not everything will be available in
172 the near future. Our first objective is to make tinc work perfectly as
173 it stands, and then add more advanced features.
175 Meanwhile, we're always open-minded towards new ideas. And we're
179 @c ==================================================================
180 @node Supported platforms
181 @section Supported platforms
184 Tinc has been verified to work under Linux, FreeBSD, OpenBSD, NetBSD, MacOS/X (Darwin), Solaris, and Windows (both natively and in a Cygwin environment),
185 with various hardware architectures. These are some of the platforms
186 that are supported by the universal tun/tap device driver or other virtual network device drivers.
187 Without such a driver, tinc will most
188 likely compile and run, but it will not be able to send or receive data
192 For an up to date list of supported platforms, please check the list on
194 @uref{http://www.tinc-vpn.org/platforms/}.
202 @c Preparing your system
209 @c ==================================================================
211 @chapter Preparations
213 This chapter contains information on how to prepare your system to
217 * Configuring the kernel::
222 @c ==================================================================
223 @node Configuring the kernel
224 @section Configuring the kernel
227 * Configuration of Linux kernels::
228 * Configuration of FreeBSD kernels::
229 * Configuration of OpenBSD kernels::
230 * Configuration of NetBSD kernels::
231 * Configuration of Solaris kernels::
232 * Configuration of Darwin (MacOS/X) kernels::
233 * Configuration of Windows::
237 @c ==================================================================
238 @node Configuration of Linux kernels
239 @subsection Configuration of Linux kernels
241 @cindex Universal tun/tap
242 For tinc to work, you need a kernel that supports the Universal tun/tap device.
243 Most distributions come with kernels that already support this.
244 Here are the options you have to turn on when configuring a new kernel:
247 Code maturity level options
248 [*] Prompt for development and/or incomplete code/drivers
249 Network device support
250 <M> Universal tun/tap device driver support
253 It's not necessary to compile this driver as a module, even if you are going to
254 run more than one instance of tinc.
256 If you decide to build the tun/tap driver as a kernel module, add these lines
257 to @file{/etc/modules.conf}:
260 alias char-major-10-200 tun
264 @c ==================================================================
265 @node Configuration of FreeBSD kernels
266 @subsection Configuration of FreeBSD kernels
268 For FreeBSD version 4.1 and higher, tun and tap drivers are included in the default kernel configuration.
269 The tap driver can be loaded with @code{kldload if_tap}, or by adding @code{if_tap_load="YES"} to @file{/boot/loader.conf}.
272 @c ==================================================================
273 @node Configuration of OpenBSD kernels
274 @subsection Configuration of OpenBSD kernels
276 For OpenBSD version 2.9 and higher,
277 the tun driver is included in the default kernel configuration.
278 There is also a kernel patch from @uref{http://diehard.n-r-g.com/stuff/openbsd/}
279 which adds a tap device to OpenBSD which should work with tinc,
280 but with recent versions of OpenBSD,
281 a tun device can act as a tap device by setting the link0 option with ifconfig.
284 @c ==================================================================
285 @node Configuration of NetBSD kernels
286 @subsection Configuration of NetBSD kernels
288 For NetBSD version 1.5.2 and higher,
289 the tun driver is included in the default kernel configuration.
291 Tunneling IPv6 may not work on NetBSD's tun device.
294 @c ==================================================================
295 @node Configuration of Solaris kernels
296 @subsection Configuration of Solaris kernels
298 For Solaris 8 (SunOS 5.8) and higher,
299 the tun driver may or may not be included in the default kernel configuration.
300 If it isn't, the source can be downloaded from @uref{http://vtun.sourceforge.net/tun/}.
301 For x86 and sparc64 architectures, precompiled versions can be found at @uref{http://www.monkey.org/~dugsong/fragroute/}.
302 If the @file{net/if_tun.h} header file is missing, install it from the source package.
305 @c ==================================================================
306 @node Configuration of Darwin (MacOS/X) kernels
307 @subsection Configuration of Darwin (MacOS/X) kernels
309 Tinc on Darwin relies on a tunnel driver for its data acquisition from the kernel.
310 Tinc supports either the driver from @uref{http://tuntaposx.sourceforge.net/},
311 which supports both tun and tap style devices,
312 and also the driver from from @uref{http://chrisp.de/en/projects/tunnel.html}.
313 The former driver is recommended.
314 The tunnel driver must be loaded before starting tinc with the following command:
321 @c ==================================================================
322 @node Configuration of Windows
323 @subsection Configuration of Windows
325 You will need to install the latest TAP-Win32 driver from OpenVPN.
326 You can download it from @uref{http://openvpn.sourceforge.net}.
327 Using the Network Connections control panel,
328 configure the TAP-Win32 network interface in the same way as you would do from the tinc-up script,
329 as explained in the rest of the documentation.
332 @c ==================================================================
338 Before you can configure or build tinc, you need to have the OpenSSL, zlib,
339 lzo, curses and readline libraries installed on your system. If you try to
340 configure tinc without having them installed, configure will give you an error
352 @c ==================================================================
357 For all cryptography-related functions, tinc uses the functions provided
358 by the OpenSSL library.
360 If this library is not installed, you wil get an error when configuring
361 tinc for build. Support for running tinc with other cryptographic libraries
362 installed @emph{may} be added in the future.
364 You can use your operating system's package manager to install this if
365 available. Make sure you install the development AND runtime versions
368 If you have to install OpenSSL manually, you can get the source code
369 from @url{http://www.openssl.org/}. Instructions on how to configure,
370 build and install this package are included within the package. Please
371 make sure you build development and runtime libraries (which is the
374 If you installed the OpenSSL libraries from source, it may be necessary
375 to let configure know where they are, by passing configure one of the
376 --with-openssl-* parameters.
379 --with-openssl=DIR OpenSSL library and headers prefix
380 --with-openssl-include=DIR OpenSSL headers directory
381 (Default is OPENSSL_DIR/include)
382 --with-openssl-lib=DIR OpenSSL library directory
383 (Default is OPENSSL_DIR/lib)
387 @subsubheading License
390 The complete source code of tinc is covered by the GNU GPL version 2.
391 Since the license under which OpenSSL is distributed is not directly
392 compatible with the terms of the GNU GPL
393 @uref{http://www.openssl.org/support/faq.html#LEGAL2}, we
394 include an exemption to the GPL (see also the file COPYING.README) to allow
395 everyone to create a statically or dynamically linked executable:
398 This program is released under the GPL with the additional exemption
399 that compiling, linking, and/or using OpenSSL is allowed. You may
400 provide binary packages linked to the OpenSSL libraries, provided that
401 all other requirements of the GPL are met.
404 Since the LZO library used by tinc is also covered by the GPL,
405 we also present the following exemption:
408 Hereby I grant a special exception to the tinc VPN project
409 (http://www.tinc-vpn.org/) to link the LZO library with the OpenSSL library
410 (http://www.openssl.org).
412 Markus F.X.J. Oberhumer
416 @c ==================================================================
421 For the optional compression of UDP packets, tinc uses the functions provided
424 If this library is not installed, you wil get an error when running the
425 configure script. You can either install the zlib library, or disable support
426 for zlib compression by using the "--disable-zlib" option when running the
427 configure script. Note that if you disable support for zlib, the resulting
428 binary will not work correctly on VPNs where zlib compression is used.
430 You can use your operating system's package manager to install this if
431 available. Make sure you install the development AND runtime versions
434 If you have to install zlib manually, you can get the source code
435 from @url{http://www.gzip.org/zlib/}. Instructions on how to configure,
436 build and install this package are included within the package. Please
437 make sure you build development and runtime libraries (which is the
441 @c ==================================================================
446 Another form of compression is offered using the LZO library.
448 If this library is not installed, you wil get an error when running the
449 configure script. You can either install the LZO library, or disable support
450 for LZO compression by using the "--disable-lzo" option when running the
451 configure script. Note that if you disable support for LZO, the resulting
452 binary will not work correctly on VPNs where LZO compression is used.
454 You can use your operating system's package manager to install this if
455 available. Make sure you install the development AND runtime versions
458 If you have to install lzo manually, you can get the source code
459 from @url{http://www.oberhumer.com/opensource/lzo/}. Instructions on how to configure,
460 build and install this package are included within the package. Please
461 make sure you build development and runtime libraries (which is the
465 @c ==================================================================
467 @subsection libcurses
470 For the "tinc top" command, tinc requires a curses library.
472 If this library is not installed, you wil get an error when running the
473 configure script. You can either install a suitable curses library, or disable
474 all functionality that depends on a curses library by using the
475 "--disable-curses" option when running the configure script.
477 There are several curses libraries. It is recommended that you install
478 "ncurses" (@url{http://invisible-island.net/ncurses/}),
479 however other curses libraries should also work.
480 In particular, "PDCurses" (@url{http://pdcurses.sourceforge.net/})
481 is recommended if you want to compile tinc for Windows.
483 You can use your operating system's package manager to install this if
484 available. Make sure you install the development AND runtime versions
488 @c ==================================================================
490 @subsection libreadline
493 For the "tinc" command's shell functionality, tinc uses the readline library.
495 If this library is not installed, you wil get an error when running the
496 configure script. You can either install a suitable readline library, or
497 disable all functionality that depends on a readline library by using the
498 "--disable-readline" option when running the configure script.
500 You can use your operating system's package manager to install this if
501 available. Make sure you install the development AND runtime versions
504 If you have to install libreadline manually, you can get the source code from
505 @url{http://www.gnu.org/software/readline/}. Instructions on how to configure,
506 build and install this package are included within the package. Please make
507 sure you build development and runtime libraries (which is the default).
519 @c ==================================================================
521 @chapter Installation
523 If you use Debian, you may want to install one of the
524 precompiled packages for your system. These packages are equipped with
525 system startup scripts and sample configurations.
527 If you cannot use one of the precompiled packages, or you want to compile tinc
528 for yourself, you can use the source. The source is distributed under
529 the GNU General Public License (GPL). Download the source from the
530 @uref{http://www.tinc-vpn.org/download/, download page}, which has
531 the checksums of these files listed; you may wish to check these with
532 md5sum before continuing.
534 Tinc comes in a convenient autoconf/automake package, which you can just
535 treat the same as any other package. Which is just untar it, type
536 `./configure' and then `make'.
537 More detailed instructions are in the file @file{INSTALL}, which is
538 included in the source distribution.
541 * Building and installing tinc::
546 @c ==================================================================
547 @node Building and installing tinc
548 @section Building and installing tinc
550 Detailed instructions on configuring the source, building tinc and installing tinc
551 can be found in the file called @file{INSTALL}.
553 @cindex binary package
554 If you happen to have a binary package for tinc for your distribution,
555 you can use the package management tools of that distribution to install tinc.
556 The documentation that comes along with your distribution will tell you how to do that.
559 * Darwin (MacOS/X) build environment::
560 * Cygwin (Windows) build environment::
561 * MinGW (Windows) build environment::
565 @c ==================================================================
566 @node Darwin (MacOS/X) build environment
567 @subsection Darwin (MacOS/X) build environment
569 In order to build tinc on Darwin, you need to install the MacOS/X Developer Tools
570 from @uref{http://developer.apple.com/tools/macosxtools.html} and
571 a recent version of Fink from @uref{http://www.finkproject.org/}.
573 After installation use fink to download and install the following packages:
574 autoconf25, automake, dlcompat, m4, openssl, zlib and lzo.
576 @c ==================================================================
577 @node Cygwin (Windows) build environment
578 @subsection Cygwin (Windows) build environment
580 If Cygwin hasn't already been installed, install it directly from
581 @uref{http://www.cygwin.com/}.
583 When tinc is compiled in a Cygwin environment, it can only be run in this environment,
584 but all programs, including those started outside the Cygwin environment, will be able to use the VPN.
585 It will also support all features.
587 @c ==================================================================
588 @node MinGW (Windows) build environment
589 @subsection MinGW (Windows) build environment
591 You will need to install the MinGW environment from @uref{http://www.mingw.org}.
593 When tinc is compiled using MinGW it runs natively under Windows,
594 it is not necessary to keep MinGW installed.
596 When detaching, tinc will install itself as a service,
597 which will be restarted automatically after reboots.
600 @c ==================================================================
602 @section System files
604 Before you can run tinc, you must make sure you have all the needed
605 files on your system.
613 @c ==================================================================
615 @subsection Device files
618 Most operating systems nowadays come with the necessary device files by default,
619 or they have a mechanism to create them on demand.
621 If you use Linux and do not have udev installed,
622 you may need to create the following device file if it does not exist:
625 mknod -m 600 /dev/net/tun c 10 200
629 @c ==================================================================
631 @subsection Other files
633 @subsubheading @file{/etc/networks}
635 You may add a line to @file{/etc/networks} so that your VPN will get a
636 symbolic name. For example:
642 @subsubheading @file{/etc/services}
645 You may add this line to @file{/etc/services}. The effect is that you
646 may supply a @samp{tinc} as a valid port number to some programs. The
647 number 655 is registered with the IANA.
652 # Ivo Timmermans <ivo@@tinc-vpn.org>
667 @c ==================================================================
669 @chapter Configuration
672 * Configuration introduction::
673 * Multiple networks::
674 * How connections work::
675 * Configuration files::
676 * Network interfaces::
677 * Example configuration::
680 @c ==================================================================
681 @node Configuration introduction
682 @section Configuration introduction
684 Before actually starting to configure tinc and editing files,
685 make sure you have read this entire section so you know what to expect.
686 Then, make it clear to yourself how you want to organize your VPN:
687 What are the nodes (computers running tinc)?
688 What IP addresses/subnets do they have?
689 What is the network mask of the entire VPN?
690 Do you need special firewall rules?
691 Do you have to set up masquerading or forwarding rules?
692 Do you want to run tinc in router mode or switch mode?
693 These questions can only be answered by yourself,
694 you will not find the answers in this documentation.
695 Make sure you have an adequate understanding of networks in general.
696 @cindex Network Administrators Guide
697 A good resource on networking is the
698 @uref{http://www.tldp.org/LDP/nag2/, Linux Network Administrators Guide}.
700 If you have everything clearly pictured in your mind,
701 proceed in the following order:
702 First, create the initial configuration files and public/private keypairs using the following command:
704 tinc -n @var{NETNAME} init @var{NAME}
706 Second, use @samp{tinc -n @var{NETNAME} add ...} to further configure tinc.
707 Finally, export your host configuration file using @samp{tinc -n @var{NETNAME} export} and send it to those
708 people or computers you want tinc to connect to.
709 They should send you their host configuration file back, which you can import using @samp{tinc -n @var{NETNAME} import}.
711 These steps are described in the subsections below.
714 @c ==================================================================
715 @node Multiple networks
716 @section Multiple networks
718 @cindex multiple networks
721 In order to allow you to run more than one tinc daemon on one computer,
722 for instance if your computer is part of more than one VPN,
723 you can assign a @var{netname} to your VPN.
724 It is not required if you only run one tinc daemon,
725 it doesn't even have to be the same on all the nodes of your VPN,
726 but it is recommended that you choose one anyway.
728 We will asume you use a netname throughout this document.
729 This means that you call tinc with the -n argument,
730 which will specify the netname.
732 The effect of this option is that tinc will set its configuration
733 root to @file{@value{sysconfdir}/tinc/@var{netname}/}, where @var{netname} is your argument to the -n option.
734 You will also notice that log messages it appears in syslog as coming from @file{tinc.@var{netname}},
735 and on Linux, unless specified otherwise, the name of the virtual network interface will be the same as the network name.
737 However, it is not strictly necessary that you call tinc with the -n
738 option. If you don not use it, the network name will just be empty, and
739 tinc will look for files in @file{@value{sysconfdir}/tinc/} instead of
740 @file{@value{sysconfdir}/tinc/@var{netname}/};
741 the configuration file will then be @file{@value{sysconfdir}/tinc/tinc.conf},
742 and the host configuration files are expected to be in @file{@value{sysconfdir}/tinc/hosts/}.
745 @c ==================================================================
746 @node How connections work
747 @section How connections work
749 When tinc starts up, it parses the command-line options and then
750 reads in the configuration file tinc.conf.
751 If it sees one or more `ConnectTo' values pointing to other tinc daemons in that file,
752 it will try to connect to those other daemons.
753 Whether this succeeds or not and whether `ConnectTo' is specified or not,
754 tinc will listen for incoming connection from other deamons.
755 If you did specify a `ConnectTo' value and the other side is not responding,
756 tinc will keep retrying.
757 This means that once started, tinc will stay running until you tell it to stop,
758 and failures to connect to other tinc daemons will not stop your tinc daemon
759 for trying again later.
760 This means you don't have to intervene if there are temporary network problems.
764 There is no real distinction between a server and a client in tinc.
765 If you wish, you can view a tinc daemon without a `ConnectTo' value as a server,
766 and one which does specify such a value as a client.
767 It does not matter if two tinc daemons have a `ConnectTo' value pointing to each other however.
769 Connections specified using `ConnectTo' are so-called meta-connections.
770 Tinc daemons exchange information about all other daemon they know about via these meta-connections.
771 After learning about all the daemons in the VPN,
772 tinc will create other connections as necessary in order to communicate with them.
773 For example, if there are three daemons named A, B and C, and A has @samp{ConnectTo = B} in its tinc.conf file,
774 and C has @samp{ConnectTo = B} in its tinc.conf file, then A will learn about C from B,
775 and will be able to exchange VPN packets with C without the need to have @samp{ConnectTo = C} in its tinc.conf file.
777 It could be that some daemons are located behind a Network Address Translation (NAT) device, or behind a firewall.
778 In the above scenario with three daemons, if A and C are behind a NAT,
779 B will automatically help A and C punch holes through their NAT,
780 in a way similar to the STUN protocol, so that A and C can still communicate with each other directly.
781 It is not always possible to do this however, and firewalls might also prevent direct communication.
782 In that case, VPN packets between A and C will be forwarded by B.
784 In effect, all nodes in the VPN will be able to talk to each other, as long as
785 their is a path of meta-connections between them, and whenever possible, two
786 nodes will communicate with each other directly.
789 @c ==================================================================
790 @node Configuration files
791 @section Configuration files
793 The actual configuration of the daemon is done in the file
794 @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf} and at least one other file in the directory
795 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/}.
797 An optionnal directory @file{@value{sysconfdir}/tinc/@var{netname}/conf.d} can be added from which
798 any .conf file will be read.
800 These file consists of comments (lines started with a #) or assignments
807 The variable names are case insensitive, and any spaces, tabs, newlines
808 and carriage returns are ignored. Note: it is not required that you put
809 in the `=' sign, but doing so improves readability. If you leave it
810 out, remember to replace it with at least one space character.
812 The server configuration is complemented with host specific configuration (see
813 the next section). Although all host configuration options for the local node
814 listed in this document can also be put in
815 @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf}, it is recommended to
816 put host specific configuration options in the host configuration file, as this
817 makes it easy to exchange with other nodes.
819 You can edit the config file manually, but it is recommended that you use
820 the tinc command to change configuration variables for you.
822 In the following two subsections all valid variables are listed in alphabetical order.
823 The default value is given between parentheses,
824 other comments are between square brackets.
827 * Main configuration variables::
828 * Host configuration variables::
834 @c ==================================================================
835 @node Main configuration variables
836 @subsection Main configuration variables
839 @cindex AddressFamily
840 @item AddressFamily = <ipv4|ipv6|any> (any)
841 This option affects the address family of listening and outgoing sockets.
842 If any is selected, then depending on the operating system
843 both IPv4 and IPv6 or just IPv6 listening sockets will be created.
846 @item AutoConnect = <count> (0) [experimental]
847 If set to a non-zero value,
848 tinc will try to only have count meta connections to other nodes,
849 by automatically making or breaking connections to known nodes.
850 Higher values increase redundancy but also increase meta data overhead.
851 When using this option, a good value is 3.
853 @cindex BindToAddress
854 @item BindToAddress = <@var{address}> [<@var{port}>]
855 This is the same as ListenAddress, however the address given with the BindToAddress option
856 will also be used for outgoing connections.
857 This is useful if your computer has more than one IPv4 or IPv6 address,
858 and you want tinc to only use a specific one for outgoing packets.
860 @cindex BindToInterface
861 @item BindToInterface = <@var{interface}> [experimental]
862 If you have more than one network interface in your computer, tinc will
863 by default listen on all of them for incoming connections. It is
864 possible to bind tinc to a single interface like eth0 or ppp0 with this
867 This option may not work on all platforms.
868 Also, on some platforms it will not actually bind to an interface,
869 but rather to the address that the interface has at the moment a socket is created.
872 @item Broadcast = <no | mst | direct> (mst) [experimental]
873 This option selects the way broadcast packets are sent to other daemons.
874 @emph{NOTE: all nodes in a VPN must use the same Broadcast mode, otherwise routing loops can form.}
878 Broadcast packets are never sent to other nodes.
881 Broadcast packets are sent and forwarded via the VPN's Minimum Spanning Tree.
882 This ensures broadcast packets reach all nodes.
885 Broadcast packets are sent directly to all nodes that can be reached directly.
886 Broadcast packets received from other nodes are never forwarded.
887 If the IndirectData option is also set, broadcast packets will only be sent to nodes which we have a meta connection to.
891 @item ConnectTo = <@var{name}>
892 Specifies which other tinc daemon to connect to on startup.
893 Multiple ConnectTo variables may be specified,
894 in which case outgoing connections to each specified tinc daemon are made.
895 The names should be known to this tinc daemon
896 (i.e., there should be a host configuration file for the name on the ConnectTo line).
898 If you don't specify a host with ConnectTo,
899 tinc won't try to connect to other daemons at all,
900 and will instead just listen for incoming connections.
903 @item DecrementTTL = <yes | no> (no) [experimental]
904 When enabled, tinc will decrement the Time To Live field in IPv4 packets, or the Hop Limit field in IPv6 packets,
905 before forwarding a received packet to the virtual network device or to another node,
906 and will drop packets that have a TTL value of zero,
907 in which case it will send an ICMP Time Exceeded packet back.
909 Do not use this option if you use switch mode and want to use IPv6.
912 @item Device = <@var{device}> (@file{/dev/tap0}, @file{/dev/net/tun} or other depending on platform)
913 The virtual network device to use.
914 Tinc will automatically detect what kind of device it is.
915 Note that you can only use one device per daemon.
916 Under Windows, use @var{Interface} instead of @var{Device}.
917 Note that you can only use one device per daemon.
918 See also @ref{Device files}.
921 @item DeviceType = <@var{type}> (platform dependent)
922 The type of the virtual network device.
923 Tinc will normally automatically select the right type of tun/tap interface, and this option should not be used.
924 However, this option can be used to select one of the special interface types, if support for them is compiled in.
929 Use a dummy interface.
930 No packets are ever read or written to a virtual network device.
931 Useful for testing, or when setting up a node that only forwards packets for other nodes.
935 Open a raw socket, and bind it to a pre-existing
936 @var{Interface} (eth0 by default).
937 All packets are read from this interface.
938 Packets received for the local node are written to the raw socket.
939 However, at least on Linux, the operating system does not process IP packets destined for the local host.
943 Open a multicast UDP socket and bind it to the address and port (separated by spaces) and optionally a TTL value specified using @var{Device}.
944 Packets are read from and written to this multicast socket.
945 This can be used to connect to UML, QEMU or KVM instances listening on the same multicast address.
946 Do NOT connect multiple tinc daemons to the same multicast address, this will very likely cause routing loops.
947 Also note that this can cause decrypted VPN packets to be sent out on a real network if misconfigured.
950 @item uml (not compiled in by default)
951 Create a UNIX socket with the filename specified by
952 @var{Device}, or @file{@value{localstatedir}/run/@var{netname}.umlsocket}
954 Tinc will wait for a User Mode Linux instance to connect to this socket.
957 @item vde (not compiled in by default)
958 Uses the libvdeplug library to connect to a Virtual Distributed Ethernet switch,
959 using the UNIX socket specified by
960 @var{Device}, or @file{@value{localstatedir}/run/vde.ctl}
964 Also, in case tinc does not seem to correctly interpret packets received from the virtual network device,
965 it can be used to change the way packets are interpreted:
968 @item tun (BSD and Linux)
970 Depending on the platform, this can either be with or without an address family header (see below).
973 @item tunnohead (BSD)
974 Set type to tun without an address family header.
975 Tinc will expect packets read from the virtual network device to start with an IP header.
976 On some platforms IPv6 packets cannot be read from or written to the device in this mode.
979 @item tunifhead (BSD)
980 Set type to tun with an address family header.
981 Tinc will expect packets read from the virtual network device
982 to start with a four byte header containing the address family,
983 followed by an IP header.
984 This mode should support both IPv4 and IPv6 packets.
986 @item tap (BSD and Linux)
988 Tinc will expect packets read from the virtual network device
989 to start with an Ethernet header.
993 @item DirectOnly = <yes|no> (no) [experimental]
994 When this option is enabled, packets that cannot be sent directly to the destination node,
995 but which would have to be forwarded by an intermediate node, are dropped instead.
996 When combined with the IndirectData option,
997 packets for nodes for which we do not have a meta connection with are also dropped.
999 @cindex ECDSAPrivateKeyFile
1000 @item ECDSAPrivateKeyFile = <@var{path}> (@file{@value{sysconfdir}/tinc/@var{netname}/ecdsa_key.priv})
1001 The file in which the private ECDSA key of this tinc daemon resides.
1002 This is only used if ExperimentalProtocol is enabled.
1004 @cindex ExperimentalProtocol
1005 @item ExperimentalProtocol = <yes|no> (yes)
1006 When this option is enabled, the SPTPS protocol will be used when connecting to nodes that also support it.
1007 Ephemeral ECDH will be used for key exchanges,
1008 and ECDSA will be used instead of RSA for authentication.
1009 When enabled, an ECDSA key must have been generated before with
1010 @samp{tinc generate-ecdsa-keys}.
1013 @item Forwarding = <off|internal|kernel> (internal) [experimental]
1014 This option selects the way indirect packets are forwarded.
1018 Incoming packets that are not meant for the local node,
1019 but which should be forwarded to another node, are dropped.
1022 Incoming packets that are meant for another node are forwarded by tinc internally.
1024 This is the default mode, and unless you really know you need another forwarding mode, don't change it.
1027 Incoming packets are always sent to the TUN/TAP device, even if the packets are not for the local node.
1028 This is less efficient, but allows the kernel to apply its routing and firewall rules on them,
1029 and can also help debugging.
1033 @item Hostnames = <yes|no> (no)
1034 This option selects whether IP addresses (both real and on the VPN)
1035 should be resolved. Since DNS lookups are blocking, it might affect
1036 tinc's efficiency, even stopping the daemon for a few seconds everytime
1037 it does a lookup if your DNS server is not responding.
1039 This does not affect resolving hostnames to IP addresses from the
1040 configuration file, but whether hostnames should be resolved while logging.
1043 @item Interface = <@var{interface}>
1044 Defines the name of the interface corresponding to the virtual network device.
1045 Depending on the operating system and the type of device this may or may not actually set the name of the interface.
1046 Under Windows, this variable is used to select which network interface will be used.
1047 If you specified a Device, this variable is almost always already correctly set.
1049 @cindex ListenAddress
1050 @item ListenAddress = <@var{address}> [<@var{port}>]
1051 If your computer has more than one IPv4 or IPv6 address, tinc
1052 will by default listen on all of them for incoming connections.
1053 This option can be used to restrict which addresses tinc listens on.
1054 Multiple ListenAddress variables may be specified,
1055 in which case listening sockets for each specified address are made.
1057 If no @var{port} is specified, the socket will listen on the port specified by the Port option,
1058 or to port 655 if neither is given.
1059 To only listen on a specific port but not to a specific address, use "*" for the @var{address}.
1061 @cindex LocalDiscovery
1062 @item LocalDiscovery = <yes | no> (no)
1063 When enabled, tinc will try to detect peers that are on the same local network.
1064 This will allow direct communication using LAN addresses, even if both peers are behind a NAT
1065 and they only ConnectTo a third node outside the NAT,
1066 which normally would prevent the peers from learning each other's LAN address.
1068 Currently, local discovery is implemented by sending broadcast packets to the LAN during path MTU discovery.
1069 This feature may not work in all possible situations.
1071 @cindex LocalDiscoveryAddress
1072 @item LocalDiscoveryAddress <@var{address}>
1073 If this variable is specified, local discovery packets are sent to the given @var{address}.
1076 @item Mode = <router|switch|hub> (router)
1077 This option selects the way packets are routed to other daemons.
1083 variables in the host configuration files will be used to form a routing table.
1084 Only packets of routable protocols (IPv4 and IPv6) are supported in this mode.
1086 This is the default mode, and unless you really know you need another mode, don't change it.
1090 In this mode the MAC addresses of the packets on the VPN will be used to
1091 dynamically create a routing table just like an Ethernet switch does.
1092 Unicast, multicast and broadcast packets of every protocol that runs over Ethernet are supported in this mode
1093 at the cost of frequent broadcast ARP requests and routing table updates.
1095 This mode is primarily useful if you want to bridge Ethernet segments.
1099 This mode is almost the same as the switch mode, but instead
1100 every packet will be broadcast to the other daemons
1101 while no routing table is managed.
1105 @item KeyExpire = <@var{seconds}> (3600)
1106 This option controls the time the encryption keys used to encrypt the data
1107 are valid. It is common practice to change keys at regular intervals to
1108 make it even harder for crackers, even though it is thought to be nearly
1109 impossible to crack a single key.
1112 @item MACExpire = <@var{seconds}> (600)
1113 This option controls the amount of time MAC addresses are kept before they are removed.
1114 This only has effect when Mode is set to "switch".
1116 @cindex MaxConnectionBurst
1117 @item MaxConnectionBurst = <@var{count}> (100)
1118 This option controls how many connections tinc accepts in quick succession.
1119 If there are more connections than the given number in a short time interval,
1120 tinc will reduce the number of accepted connections to only one per second,
1121 until the burst has passed.
1124 @item Name = <@var{name}> [required]
1125 This is a symbolic name for this connection.
1126 The name should consist only of alfanumeric and underscore characters (a-z, A-Z, 0-9 and _), and is case sensitive.
1128 If Name starts with a $, then the contents of the environment variable that follows will be used.
1129 In that case, invalid characters will be converted to underscores.
1130 If Name is $HOST, but no such environment variable exist,
1131 the hostname will be read using the gethostname() system call.
1133 @cindex PingInterval
1134 @item PingInterval = <@var{seconds}> (60)
1135 The number of seconds of inactivity that tinc will wait before sending a
1136 probe to the other end.
1139 @item PingTimeout = <@var{seconds}> (5)
1140 The number of seconds to wait for a response to pings or to allow meta
1141 connections to block. If the other end doesn't respond within this time,
1142 the connection is terminated, and the others will be notified of this.
1144 @cindex PriorityInheritance
1145 @item PriorityInheritance = <yes|no> (no) [experimental]
1146 When this option is enabled the value of the TOS field of tunneled IPv4 packets
1147 will be inherited by the UDP packets that are sent out.
1150 @item PrivateKey = <@var{key}> [obsolete]
1151 This is the RSA private key for tinc. However, for safety reasons it is
1152 advised to store private keys of any kind in separate files. This prevents
1153 accidental eavesdropping if you are editting the configuration file.
1155 @cindex PrivateKeyFile
1156 @item PrivateKeyFile = <@var{path}> (@file{@value{sysconfdir}/tinc/@var{netname}/rsa_key.priv})
1157 This is the full path name of the RSA private key file that was
1158 generated by @samp{tinc generate-keys}. It must be a full path, not a
1161 @cindex ProcessPriority
1162 @item ProcessPriority = <low|normal|high>
1163 When this option is used the priority of the tincd process will be adjusted.
1164 Increasing the priority may help to reduce latency and packet loss on the VPN.
1167 @item Proxy = socks4 | socks5 | http | exec @var{...} [experimental]
1168 Use a proxy when making outgoing connections.
1169 The following proxy types are currently supported:
1173 @item socks4 <@var{address}> <@var{port}> [<@var{username}>]
1174 Connects to the proxy using the SOCKS version 4 protocol.
1175 Optionally, a @var{username} can be supplied which will be passed on to the proxy server.
1178 @item socks5 <@var{address}> <@var{port}> [<@var{username}> <@var{password}>]
1179 Connect to the proxy using the SOCKS version 5 protocol.
1180 If a @var{username} and @var{password} are given, basic username/password authentication will be used,
1181 otherwise no authentication will be used.
1184 @item http <@var{address}> <@var{port}>
1185 Connects to the proxy and sends a HTTP CONNECT request.
1188 @item exec <@var{command}>
1189 Executes the given command which should set up the outgoing connection.
1190 The environment variables @env{NAME}, @env{NODE}, @env{REMOTEADDRES} and @env{REMOTEPORT} are available.
1193 @cindex ReplayWindow
1194 @item ReplayWindow = <bytes> (16)
1195 This is the size of the replay tracking window for each remote node, in bytes.
1196 The window is a bitfield which tracks 1 packet per bit, so for example
1197 the default setting of 16 will track up to 128 packets in the window. In high
1198 bandwidth scenarios, setting this to a higher value can reduce packet loss from
1199 the interaction of replay tracking with underlying real packet loss and/or
1200 reordering. Setting this to zero will disable replay tracking completely and
1201 pass all traffic, but leaves tinc vulnerable to replay-based attacks on your
1204 @cindex StrictSubnets
1205 @item StrictSubnets = <yes|no> (no) [experimental]
1206 When this option is enabled tinc will only use Subnet statements which are
1207 present in the host config files in the local
1208 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
1209 Subnets learned via connections to other nodes and which are not
1210 present in the local host config files are ignored.
1212 @cindex TunnelServer
1213 @item TunnelServer = <yes|no> (no) [experimental]
1214 When this option is enabled tinc will no longer forward information between other tinc daemons,
1215 and will only allow connections with nodes for which host config files are present in the local
1216 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
1217 Setting this options also implicitly sets StrictSubnets.
1220 @item UDPRcvBuf = <bytes> (OS default)
1221 Sets the socket receive buffer size for the UDP socket, in bytes.
1222 If unset, the default buffer size will be used by the operating system.
1225 @item UDPSndBuf = <bytes> Pq OS default
1226 Sets the socket send buffer size for the UDP socket, in bytes.
1227 If unset, the default buffer size will be used by the operating system.
1232 @c ==================================================================
1233 @node Host configuration variables
1234 @subsection Host configuration variables
1238 @item Address = <@var{IP address}|@var{hostname}> [<port>] [recommended]
1239 This variable is only required if you want to connect to this host. It
1240 must resolve to the external IP address where the host can be reached,
1241 not the one that is internal to the VPN.
1242 If no port is specified, the default Port is used.
1243 Multiple Address variables can be specified, in which case each address will be
1244 tried until a working connection has been established.
1247 @item Cipher = <@var{cipher}> (blowfish)
1248 The symmetric cipher algorithm used to encrypt UDP packets using the legacy protocol.
1249 Any cipher supported by OpenSSL is recognized.
1250 Furthermore, specifying "none" will turn off packet encryption.
1251 It is best to use only those ciphers which support CBC mode.
1252 This option has no effect for connections using the SPTPS protocol, which always use AES-256-CTR.
1255 @item ClampMSS = <yes|no> (yes)
1256 This option specifies whether tinc should clamp the maximum segment size (MSS)
1257 of TCP packets to the path MTU. This helps in situations where ICMP
1258 Fragmentation Needed or Packet too Big messages are dropped by firewalls.
1261 @item Compression = <@var{level}> (0)
1262 This option sets the level of compression used for UDP packets.
1263 Possible values are 0 (off), 1 (fast zlib) and any integer up to 9 (best zlib),
1264 10 (fast lzo) and 11 (best lzo).
1267 @item Digest = <@var{digest}> (sha1)
1268 The digest algorithm used to authenticate UDP packets using the legacy protocol.
1269 Any digest supported by OpenSSL is recognized.
1270 Furthermore, specifying "none" will turn off packet authentication.
1271 This option has no effect for connections using the SPTPS protocol, which always use HMAC-SHA-256.
1273 @cindex IndirectData
1274 @item IndirectData = <yes|no> (no)
1275 When set to yes, other nodes which do not already have a meta connection to you
1276 will not try to establish direct communication with you.
1277 It is best to leave this option out or set it to no.
1280 @item MACLength = <@var{bytes}> (4)
1281 The length of the message authentication code used to authenticate UDP packets using the legacy protocol.
1282 Can be anything from 0
1283 up to the length of the digest produced by the digest algorithm.
1284 This option has no effect for connections using the SPTPS protocol, which never truncate MACs.
1287 @item PMTU = <@var{mtu}> (1514)
1288 This option controls the initial path MTU to this node.
1290 @cindex PMTUDiscovery
1291 @item PMTUDiscovery = <yes|no> (yes)
1292 When this option is enabled, tinc will try to discover the path MTU to this node.
1293 After the path MTU has been discovered, it will be enforced on the VPN.
1296 @item Port = <@var{port}> (655)
1297 This is the port this tinc daemon listens on.
1298 You can use decimal portnumbers or symbolic names (as listed in @file{/etc/services}).
1301 @item PublicKey = <@var{key}> [obsolete]
1302 This is the RSA public key for this host.
1304 @cindex PublicKeyFile
1305 @item PublicKeyFile = <@var{path}> [obsolete]
1306 This is the full path name of the RSA public key file that was generated
1307 by @samp{tinc generate-keys}. It must be a full path, not a relative
1311 From version 1.0pre4 on tinc will store the public key directly into the
1312 host configuration file in PEM format, the above two options then are not
1313 necessary. Either the PEM format is used, or exactly
1314 @strong{one of the above two options} must be specified
1315 in each host configuration file, if you want to be able to establish a
1316 connection with that host.
1319 @item Subnet = <@var{address}[/@var{prefixlength}[#@var{weight}]]>
1320 The subnet which this tinc daemon will serve.
1321 Tinc tries to look up which other daemon it should send a packet to by searching the appropiate subnet.
1322 If the packet matches a subnet,
1323 it will be sent to the daemon who has this subnet in his host configuration file.
1324 Multiple subnet lines can be specified for each daemon.
1326 Subnets can either be single MAC, IPv4 or IPv6 addresses,
1327 in which case a subnet consisting of only that single address is assumed,
1328 or they can be a IPv4 or IPv6 network address with a prefixlength.
1329 For example, IPv4 subnets must be in a form like 192.168.1.0/24,
1330 where 192.168.1.0 is the network address and 24 is the number of bits set in the netmask.
1331 Note that subnets like 192.168.1.1/24 are invalid!
1332 Read a networking HOWTO/FAQ/guide if you don't understand this.
1333 IPv6 subnets are notated like fec0:0:0:1::/64.
1334 MAC addresses are notated like 0:1a:2b:3c:4d:5e.
1336 @cindex CIDR notation
1337 Prefixlength is the number of bits set to 1 in the netmask part; for
1338 example: netmask 255.255.255.0 would become /24, 255.255.252.0 becomes
1339 /22. This conforms to standard CIDR notation as described in
1340 @uref{http://www.ietf.org/rfc/rfc1519.txt, RFC1519}
1342 A Subnet can be given a weight to indicate its priority over identical Subnets
1343 owned by different nodes. The default weight is 10. Lower values indicate
1344 higher priority. Packets will be sent to the node with the highest priority,
1345 unless that node is not reachable, in which case the node with the next highest
1346 priority will be tried, and so on.
1349 @item TCPonly = <yes|no> (no)
1350 If this variable is set to yes, then the packets are tunnelled over a
1351 TCP connection instead of a UDP connection. This is especially useful
1352 for those who want to run a tinc daemon from behind a masquerading
1353 firewall, or if UDP packet routing is disabled somehow.
1354 Setting this options also implicitly sets IndirectData.
1358 @c ==================================================================
1363 Apart from reading the server and host configuration files,
1364 tinc can also run scripts at certain moments.
1365 Under Windows (not Cygwin), the scripts should have the extension @file{.bat} or @file{.cmd}.
1369 @item @value{sysconfdir}/tinc/@var{netname}/tinc-up
1370 This is the most important script.
1371 If it is present it will be executed right after the tinc daemon has been
1372 started and has connected to the virtual network device.
1373 It should be used to set up the corresponding network interface,
1374 but can also be used to start other things.
1375 Under Windows you can use the Network Connections control panel instead of creating this script.
1378 @item @value{sysconfdir}/tinc/@var{netname}/tinc-down
1379 This script is started right before the tinc daemon quits.
1381 @item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-up
1382 This script is started when the tinc daemon with name @var{host} becomes reachable.
1384 @item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-down
1385 This script is started when the tinc daemon with name @var{host} becomes unreachable.
1387 @item @value{sysconfdir}/tinc/@var{netname}/host-up
1388 This script is started when any host becomes reachable.
1390 @item @value{sysconfdir}/tinc/@var{netname}/host-down
1391 This script is started when any host becomes unreachable.
1393 @item @value{sysconfdir}/tinc/@var{netname}/subnet-up
1394 This script is started when a Subnet becomes reachable.
1395 The Subnet and the node it belongs to are passed in environment variables.
1397 @item @value{sysconfdir}/tinc/@var{netname}/subnet-down
1398 This script is started when a Subnet becomes unreachable.
1400 @item @value{sysconfdir}/tinc/@var{netname}/invitation-created
1401 This script is started when a new invitation has been created.
1403 @item @value{sysconfdir}/tinc/@var{netname}/invitation-accepted
1404 This script is started when an invitation has been used.
1408 @cindex environment variables
1409 The scripts are started without command line arguments,
1410 but can make use of certain environment variables.
1411 Under UNIX like operating systems the names of environment variables must be preceded by a $ in scripts.
1412 Under Windows, in @file{.bat} or @file{.cmd} files, they have to be put between % signs.
1417 If a netname was specified, this environment variable contains it.
1421 Contains the name of this tinc daemon.
1425 Contains the name of the virtual network device that tinc uses.
1429 Contains the name of the virtual network interface that tinc uses.
1430 This should be used for commands like ifconfig.
1434 When a host becomes (un)reachable, this is set to its name.
1435 If a subnet becomes (un)reachable, this is set to the owner of that subnet.
1437 @cindex REMOTEADDRESS
1439 When a host becomes (un)reachable, this is set to its real address.
1443 When a host becomes (un)reachable,
1444 this is set to the port number it uses for communication with other tinc daemons.
1448 When a subnet becomes (un)reachable, this is set to the subnet.
1452 When a subnet becomes (un)reachable, this is set to the subnet weight.
1454 @cindex INVITATION_FILE
1455 @item INVITATION_FILE
1456 When the @file{invitation-created} script is called,
1457 this is set to the file where the invitation details will be stored.
1459 @cindex INVITATION_URL
1460 @item INVITATION_URL
1461 When the @file{invitation-created} script is called,
1462 this is set to the invitation URL that has been created.
1465 Do not forget that under UNIX operating systems,
1466 you have to make the scripts executable, using the command @samp{chmod a+x script}.
1469 @c ==================================================================
1470 @node How to configure
1471 @subsection How to configure
1473 @subsubheading Step 1. Creating initial configuration files.
1475 The initial directory structure, configuration files and public/private keypairs are created using the following command:
1478 tinc -n @var{netname} init @var{name}
1481 (You will need to run this as root, or use "sudo".)
1482 This will create the configuration directory @file{@value{sysconfdir}/tinc/@var{netname}.},
1483 and inside it will create another directory named @file{hosts/}.
1484 In the configuration directory, it will create the file @file{tinc.conf} with the following contents:
1490 It will also create private RSA and ECDSA keys, which will be stored in the files @file{rsa_key.priv} and @file{ecdsa_key.priv}.
1491 It will also create a host configuration file @file{hosts/@var{name}},
1492 which will contain the corresponding public RSA and ECDSA keys.
1494 Finally, on UNIX operating systems, it will create an executable script @file{tinc-up},
1495 which will initially not do anything except warning that you should edit it.
1497 @subsubheading Step 2. Modifying the initial configuration.
1499 Unless you want to use tinc in switch mode,
1500 you should now configure which range of addresses you will use on the VPN.
1501 Let's assume you will be part of a VPN which uses the address range 192.168.0.0/16,
1502 and you yourself have a smaller portion of that range: 192.168.2.0/24.
1503 Then you should run the following command:
1506 tinc -n @var{netname} add subnet 192.168.2.0/24
1509 This will add a Subnet statement to your host configuration file.
1510 Try opening the file @file{@value{sysconfdir}/tinc/@var{netname}/hosts/@var{name}} in an editor.
1511 You should now see a file containing the public RSA and ECDSA keys (which looks like a bunch of random characters),
1512 and the following line at the bottom:
1515 Subnet = 192.168.2.0/24
1518 If you will use more than one address range, you can add more Subnets.
1519 For example, if you also use the IPv6 subnet fec0:0:0:2::/64, you can add it as well:
1522 tinc -n @var{netname} add subnet fec0:0:0:2::/24
1525 This will add another line to the file @file{hosts/@var{name}}.
1526 If you make a mistake, you can undo it by simply using @samp{del} instead of @samp{add}.
1528 If you want other tinc daemons to create meta-connections to your daemon,
1529 you should add your public IP address or hostname to your host configuration file.
1530 For example, if your hostname is foo.example.org, run:
1533 tinc -n @var{netname} add address foo.example.org
1536 If you already know to which daemons your daemon should make meta-connections,
1537 you should configure that now as well.
1538 Suppose you want to connect to a daemon named "bar", run:
1541 tinc -n @var{netname} add connectto bar
1544 Note that you specify the Name of the other daemon here, not an IP address or hostname!
1545 When you start tinc, and it tries to make a connection to "bar",
1546 it will look for a host configuration file named @file{hosts/bar},
1547 and will read Address statements and public keys from that file.
1549 @subsubheading Step 2. Exchanging configuration files.
1551 If your daemon has a ConnectTo = bar statement in its @file{tinc.conf} file,
1552 or if bar has a ConnectTo your daemon, then you both need each other's host configuration files.
1553 You should send @file{hosts/@var{name}} to bar, and bar should send you his file which you should move to @file{hosts/bar}.
1554 If you are on a UNIX platform, you can easily send an email containing the necessary information using the following command
1555 (assuming the owner of bar has the email address bar@@example.org):
1558 tinc -n @var{netname} export | mail -s "My config file" bar@@example.org
1561 If the owner of bar does the same to send his host configuration file to you,
1562 you can probably pipe his email through the following command,
1563 or you can just start this command in a terminal and copy&paste the email:
1566 tinc -n @var{netname} import
1569 If you are the owner of bar yourself, and you have SSH access to that computer,
1570 you can also swap the host configuration files using the following command:
1573 tinc -n @var{netname} export \
1574 | ssh bar.example.org tinc -n @var{netname} exchange \
1575 | tinc -n @var{netname} import
1578 You should repeat this for all nodes you ConnectTo, or which ConnectTo you.
1579 However, remember that you do not need to ConnectTo all nodes in the VPN;
1580 it is only necessary to create one or a few meta-connections,
1581 after the connections are made tinc will learn about all the other nodes in the VPN,
1582 and will automatically make other connections as necessary.
1585 @c ==================================================================
1586 @node Network interfaces
1587 @section Network interfaces
1589 Before tinc can start transmitting data over the tunnel, it must
1590 set up the virtual network interface.
1592 First, decide which IP addresses you want to have associated with these
1593 devices, and what network mask they must have.
1595 Tinc will open a virtual network device (@file{/dev/tun}, @file{/dev/tap0} or similar),
1596 which will also create a network interface called something like @samp{tun0}, @samp{tap0}.
1597 If you are using the Linux tun/tap driver, the network interface will by default have the same name as the @var{netname}.
1598 Under Windows you can change the name of the network interface from the Network Connections control panel.
1601 You can configure the network interface by putting ordinary ifconfig, route, and other commands
1602 to a script named @file{@value{sysconfdir}/tinc/@var{netname}/tinc-up}.
1603 When tinc starts, this script will be executed. When tinc exits, it will execute the script named
1604 @file{@value{sysconfdir}/tinc/@var{netname}/tinc-down}, but normally you don't need to create that script.
1605 You can manually open the script in an editor, or use the following command:
1608 tinc -n @var{netname} edit tinc-up
1611 An example @file{tinc-up} script, that would be appropriate for the scenario in the previous section, is:
1615 ifconfig $INTERFACE 192.168.2.1 netmask 255.255.0.0
1616 ip addr add fec0:0:0:2::/48 dev $INTERFACE
1619 The first command gives the interface an IPv4 address and a netmask.
1620 The kernel will also automatically add an IPv4 route to this interface, so normally you don't need
1621 to add route commands to the @file{tinc-up} script.
1622 The kernel will also bring the interface up after this command.
1624 The netmask is the mask of the @emph{entire} VPN network, not just your
1626 The second command gives the interface an IPv6 address and netmask,
1627 which will also automatically add an IPv6 route.
1628 If you only want to use "ip addr" commands on Linux, don't forget that it doesn't bring the interface up, unlike ifconfig,
1629 so you need to add @samp{ip link set $INTERFACE up} in that case.
1631 The exact syntax of the ifconfig and route commands differs from platform to platform.
1632 You can look up the commands for setting addresses and adding routes in @ref{Platform specific information},
1633 but it is best to consult the manpages of those utilities on your platform.
1636 @c ==================================================================
1637 @node Example configuration
1638 @section Example configuration
1642 Imagine the following situation. Branch A of our example `company' wants to connect
1643 three branch offices in B, C and D using the Internet. All four offices
1644 have a 24/7 connection to the Internet.
1646 A is going to serve as the center of the network. B and C will connect
1647 to A, and D will connect to C. Each office will be assigned their own IP
1651 A: net 10.1.0.0 mask 255.255.0.0 gateway 10.1.54.1 internet IP 1.2.3.4
1652 B: net 10.2.0.0 mask 255.255.0.0 gateway 10.2.1.12 internet IP 2.3.4.5
1653 C: net 10.3.0.0 mask 255.255.0.0 gateway 10.3.69.254 internet IP 3.4.5.6
1654 D: net 10.4.0.0 mask 255.255.0.0 gateway 10.4.3.32 internet IP 4.5.6.7
1657 Here, ``gateway'' is the VPN IP address of the machine that is running the
1658 tincd, and ``internet IP'' is the IP address of the firewall, which does not
1659 need to run tincd, but it must do a port forwarding of TCP and UDP on port
1660 655 (unless otherwise configured).
1662 In this example, it is assumed that eth0 is the interface that points to
1663 the inner (physical) LAN of the office, although this could also be the
1664 same as the interface that leads to the Internet. The configuration of
1665 the real interface is also shown as a comment, to give you an idea of
1666 how these example host is set up. All branches use the netname `company'
1667 for this particular VPN.
1669 Each branch is set up using the @samp{tinc init} and @samp{tinc config} commands,
1670 here we just show the end results:
1672 @subsubheading For Branch A
1674 @emph{BranchA} would be configured like this:
1676 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1681 # Real interface of internal network:
1682 # ifconfig eth0 10.1.54.1 netmask 255.255.0.0
1684 ifconfig $INTERFACE 10.1.54.1 netmask 255.0.0.0
1687 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1693 On all hosts, @file{@value{sysconfdir}/tinc/company/hosts/BranchA} contains:
1696 Subnet = 10.1.0.0/16
1699 -----BEGIN RSA PUBLIC KEY-----
1701 -----END RSA PUBLIC KEY-----
1704 Note that the IP addresses of eth0 and the VPN interface are the same.
1705 This is quite possible, if you make sure that the netmasks of the interfaces are different.
1706 It is in fact recommended to give both real internal network interfaces and VPN interfaces the same IP address,
1707 since that will make things a lot easier to remember and set up.
1710 @subsubheading For Branch B
1712 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1717 # Real interface of internal network:
1718 # ifconfig eth0 10.2.43.8 netmask 255.255.0.0
1720 ifconfig $INTERFACE 10.2.1.12 netmask 255.0.0.0
1723 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1730 Note here that the internal address (on eth0) doesn't have to be the
1731 same as on the VPN interface. Also, ConnectTo is given so that this node will
1732 always try to connect to BranchA.
1734 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchB}:
1737 Subnet = 10.2.0.0/16
1740 -----BEGIN RSA PUBLIC KEY-----
1742 -----END RSA PUBLIC KEY-----
1746 @subsubheading For Branch C
1748 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1753 # Real interface of internal network:
1754 # ifconfig eth0 10.3.69.254 netmask 255.255.0.0
1756 ifconfig $INTERFACE 10.3.69.254 netmask 255.0.0.0
1759 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1766 C already has another daemon that runs on port 655, so they have to
1767 reserve another port for tinc. It knows the portnumber it has to listen on
1768 from it's own host configuration file.
1770 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchC}:
1774 Subnet = 10.3.0.0/16
1777 -----BEGIN RSA PUBLIC KEY-----
1779 -----END RSA PUBLIC KEY-----
1783 @subsubheading For Branch D
1785 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1790 # Real interface of internal network:
1791 # ifconfig eth0 10.4.3.32 netmask 255.255.0.0
1793 ifconfig $INTERFACE 10.4.3.32 netmask 255.0.0.0
1796 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1803 D will be connecting to C, which has a tincd running for this network on
1804 port 2000. It knows the port number from the host configuration file.
1806 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchD}:
1809 Subnet = 10.4.0.0/16
1812 -----BEGIN RSA PUBLIC KEY-----
1814 -----END RSA PUBLIC KEY-----
1817 @subsubheading Key files
1819 A, B, C and D all have their own public/private keypairs:
1821 The private RSA key is stored in @file{@value{sysconfdir}/tinc/company/rsa_key.priv},
1822 the private ECDSA key is stored in @file{@value{sysconfdir}/tinc/company/ecdsa_key.priv},
1823 and the public RSA and ECDSA keys are put into the host configuration file in the @file{@value{sysconfdir}/tinc/company/hosts/} directory.
1825 @subsubheading Starting
1827 After each branch has finished configuration and they have distributed
1828 the host configuration files amongst them, they can start their tinc daemons.
1829 They don't necessarily have to wait for the other branches to have started
1830 their daemons, tinc will try connecting until they are available.
1833 @c ==================================================================
1835 @chapter Running tinc
1837 If everything else is done, you can start tinc by typing the following command:
1840 tinc -n @var{netname} start
1844 Tinc will detach from the terminal and continue to run in the background like a good daemon.
1845 If there are any problems however you can try to increase the debug level
1846 and look in the syslog to find out what the problems are.
1852 * Solving problems::
1854 * Sending bug reports::
1858 @c ==================================================================
1859 @node Runtime options
1860 @section Runtime options
1862 Besides the settings in the configuration file, tinc also accepts some
1863 command line options.
1865 @cindex command line
1866 @cindex runtime options
1870 @item -c, --config=@var{path}
1871 Read configuration options from the directory @var{path}. The default is
1872 @file{@value{sysconfdir}/tinc/@var{netname}/}.
1874 @item -D, --no-detach
1875 Don't fork and detach.
1876 This will also disable the automatic restart mechanism for fatal errors.
1879 @item -d, --debug=@var{level}
1880 Set debug level to @var{level}. The higher the debug level, the more gets
1881 logged. Everything goes via syslog.
1883 @item -n, --net=@var{netname}
1884 Use configuration for net @var{netname}.
1885 This will let tinc read all configuration files from
1886 @file{@value{sysconfdir}/tinc/@var{netname}/}.
1887 Specifying . for @var{netname} is the same as not specifying any @var{netname}.
1888 @xref{Multiple networks}.
1890 @item --pidfile=@var{filename}
1891 Store a cookie in @var{filename} which allows tinc to authenticate.
1892 If unspecified, the default is
1893 @file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
1895 @item -o, --option=[@var{HOST}.]@var{KEY}=@var{VALUE}
1896 Without specifying a @var{HOST}, this will set server configuration variable @var{KEY} to @var{VALUE}.
1897 If specified as @var{HOST}.@var{KEY}=@var{VALUE},
1898 this will set the host configuration variable @var{KEY} of the host named @var{HOST} to @var{VALUE}.
1899 This option can be used more than once to specify multiple configuration variables.
1902 Lock tinc into main memory.
1903 This will prevent sensitive data like shared private keys to be written to the system swap files/partitions.
1905 This option is not supported on all platforms.
1907 @item --logfile[=@var{file}]
1908 Write log entries to a file instead of to the system logging facility.
1909 If @var{file} is omitted, the default is @file{@value{localstatedir}/log/tinc.@var{netname}.log}.
1911 @item --bypass-security
1912 Disables encryption and authentication.
1913 Only useful for debugging.
1916 Change process root directory to the directory where the config file is
1917 located (@file{@value{sysconfdir}/tinc/@var{netname}/} as determined by
1918 -n/--net option or as given by -c/--config option), for added security.
1919 The chroot is performed after all the initialization is done, after
1920 writing pid files and opening network sockets.
1922 Note that this option alone does not do any good without -U/--user, below.
1924 Note also that tinc can't run scripts anymore (such as tinc-down or host-up),
1925 unless it's setup to be runnable inside chroot environment.
1927 This option is not supported on all platforms.
1928 @item -U, --user=@var{user}
1929 Switch to the given @var{user} after initialization, at the same time as
1930 chroot is performed (see --chroot above). With this option tinc drops
1931 privileges, for added security.
1933 This option is not supported on all platforms.
1936 Display a short reminder of these runtime options and terminate.
1939 Output version information and exit.
1943 @c ==================================================================
1948 You can also send the following signals to a running tincd process:
1954 Forces tinc to try to connect to all uplinks immediately.
1955 Usually tinc attempts to do this itself,
1956 but increases the time it waits between the attempts each time it failed,
1957 and if tinc didn't succeed to connect to an uplink the first time after it started,
1958 it defaults to the maximum time of 15 minutes.
1961 Partially rereads configuration files.
1962 Connections to hosts whose host config file are removed are closed.
1963 New outgoing connections specified in @file{tinc.conf} will be made.
1964 If the --logfile option is used, this will also close and reopen the log file,
1965 useful when log rotation is used.
1969 @c ==================================================================
1971 @section Debug levels
1973 @cindex debug levels
1974 The tinc daemon can send a lot of messages to the syslog.
1975 The higher the debug level, the more messages it will log.
1976 Each level inherits all messages of the previous level:
1982 This will log a message indicating tinc has started along with a version number.
1983 It will also log any serious error.
1986 This will log all connections that are made with other tinc daemons.
1989 This will log status and error messages from scripts and other tinc daemons.
1992 This will log all requests that are exchanged with other tinc daemons. These include
1993 authentication, key exchange and connection list updates.
1996 This will log a copy of everything received on the meta socket.
1999 This will log all network traffic over the virtual private network.
2003 @c ==================================================================
2004 @node Solving problems
2005 @section Solving problems
2007 If tinc starts without problems, but if the VPN doesn't work, you will have to find the cause of the problem.
2008 The first thing to do is to start tinc with a high debug level in the foreground,
2009 so you can directly see everything tinc logs:
2012 tincd -n @var{netname} -d5 -D
2015 If tinc does not log any error messages, then you might want to check the following things:
2018 @item @file{tinc-up} script
2019 Does this script contain the right commands?
2020 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.
2023 Does the Subnet (or Subnets) in the host configuration file of this host match the portion of the VPN that belongs to this host?
2025 @item Firewalls and NATs
2026 Do you have a firewall or a NAT device (a masquerading firewall or perhaps an ADSL router that performs masquerading)?
2027 If so, check that it allows TCP and UDP traffic on port 655.
2028 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.
2029 You can add @samp{TCPOnly = yes} to your host config file to force tinc to only use a single TCP connection,
2030 this works through most firewalls and NATs.
2035 @c ==================================================================
2036 @node Error messages
2037 @section Error messages
2039 What follows is a list of the most common error messages you might find in the logs.
2040 Some of them will only be visible if the debug level is high enough.
2043 @item Could not open /dev/tap0: No such device
2046 @item You forgot to `modprobe netlink_dev' or `modprobe ethertap'.
2047 @item You forgot to compile `Netlink device emulation' in the kernel.
2050 @item Can't write to /dev/net/tun: No such device
2053 @item You forgot to `modprobe tun'.
2054 @item You forgot to compile `Universal TUN/TAP driver' in the kernel.
2055 @item The tun device is located somewhere else in @file{/dev/}.
2058 @item Network address and prefix length do not match!
2061 @item The Subnet field must contain a @emph{network} address, trailing bits should be 0.
2062 @item If you only want to use one IP address, set the netmask to /32.
2065 @item Error reading RSA key file `rsa_key.priv': No such file or directory
2068 @item You forgot to create a public/private keypair.
2069 @item Specify the complete pathname to the private key file with the @samp{PrivateKeyFile} option.
2072 @item Warning: insecure file permissions for RSA private key file `rsa_key.priv'!
2075 @item The private key file is readable by users other than root.
2076 Use chmod to correct the file permissions.
2079 @item Creating metasocket failed: Address family not supported
2082 @item By default tinc tries to create both IPv4 and IPv6 sockets.
2083 On some platforms this might not be implemented.
2084 If the logs show @samp{Ready} later on, then at least one metasocket was created,
2085 and you can ignore this message.
2086 You can add @samp{AddressFamily = ipv4} to @file{tinc.conf} to prevent this from happening.
2089 @item Cannot route packet: unknown IPv4 destination 1.2.3.4
2092 @item You try to send traffic to a host on the VPN for which no Subnet is known.
2093 @item If it is a broadcast address (ending in .255), it probably is a samba server or a Windows host sending broadcast packets.
2097 @item Cannot route packet: ARP request for unknown address 1.2.3.4
2100 @item You try to send traffic to a host on the VPN for which no Subnet is known.
2103 @item Packet with destination 1.2.3.4 is looping back to us!
2106 @item Something is not configured right. Packets are being sent out to the
2107 virtual network device, but according to the Subnet directives in your host configuration
2108 file, those packets should go to your own host. Most common mistake is that
2109 you have a Subnet line in your host configuration file with a prefix length which is
2110 just as large as the prefix of the virtual network interface. The latter should in almost all
2111 cases be larger. Rethink your configuration.
2112 Note that you will only see this message if you specified a debug
2113 level of 5 or higher!
2114 @item Chances are that a @samp{Subnet = ...} line in the host configuration file of this tinc daemon is wrong.
2115 Change it to a subnet that is accepted locally by another interface,
2116 or if that is not the case, try changing the prefix length into /32.
2119 @item Node foo (1.2.3.4) is not reachable
2122 @item Node foo does not have a connection anymore, its tinc daemon is not running or its connection to the Internet is broken.
2125 @item Received UDP packet from unknown source 1.2.3.4 (port 12345)
2128 @item If you see this only sporadically, it is harmless and caused by a node sending packets using an old key.
2129 @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.
2130 You can add @samp{TCPOnly = yes} to host configuration files to force all VPN traffic to go over a TCP connection.
2133 @item Got bad/bogus/unauthorized REQUEST from foo (1.2.3.4 port 12345)
2136 @item Node foo does not have the right public/private keypair.
2137 Generate new keypairs and distribute them again.
2138 @item An attacker tries to gain access to your VPN.
2139 @item A network error caused corruption of metadata sent from foo.
2144 @c ==================================================================
2145 @node Sending bug reports
2146 @section Sending bug reports
2148 If you really can't find the cause of a problem, or if you suspect tinc is not working right,
2149 you can send us a bugreport, see @ref{Contact information}.
2150 Be sure to include the following information in your bugreport:
2153 @item A clear description of what you are trying to achieve and what the problem is.
2154 @item What platform (operating system, version, hardware architecture) and which version of tinc you use.
2155 @item If compiling tinc fails, a copy of @file{config.log} and the error messages you get.
2156 @item Otherwise, a copy of @file{tinc.conf}, @file{tinc-up} and all files in the @file{hosts/} directory.
2157 @item The output of the commands @samp{ifconfig -a} and @samp{route -n} (or @samp{netstat -rn} if that doesn't work).
2158 @item The output of any command that fails to work as it should (like ping or traceroute).
2161 @c ==================================================================
2162 @node Controlling tinc
2163 @chapter Controlling tinc
2165 @cindex command line interface
2166 You can start, stop, control and inspect a running tincd through the tinc
2167 command. A quick example:
2170 tinc -n @var{netname} reload
2174 If tinc is started without a command, it will act as a shell; it will display a
2175 prompt, and commands can be entered on the prompt. If tinc is compiled with
2176 libreadline, history and command completion are available on the prompt. One
2177 can also pipe a script containing commands through tinc. In that case, lines
2178 starting with a # symbol will be ignored.
2181 * tinc runtime options::
2182 * tinc environment variables::
2189 @c ==================================================================
2190 @node tinc runtime options
2191 @section tinc runtime options
2195 @item -c, --config=@var{path}
2196 Read configuration options from the directory @var{path}. The default is
2197 @file{@value{sysconfdir}/tinc/@var{netname}/}.
2199 @item -n, --net=@var{netname}
2200 Use configuration for net @var{netname}. @xref{Multiple networks}.
2202 @item --pidfile=@var{filename}
2203 Use the cookie from @var{filename} to authenticate with a running tinc daemon.
2204 If unspecified, the default is
2205 @file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
2208 Display a short reminder of runtime options and commands, then terminate.
2211 Output version information and exit.
2215 @c ==================================================================
2216 @node tinc environment variables
2217 @section tinc environment variables
2222 If no netname is specified on the command line with the @option{-n} option,
2223 the value of this environment variable is used.
2226 @c ==================================================================
2228 @section tinc commands
2234 @item init [@var{name}]
2235 Create initial configuration files and RSA and ECDSA keypairs with default length.
2236 If no @var{name} for this node is given, it will be asked for.
2239 @item get @var{variable}
2240 Print the current value of configuration variable @var{variable}.
2241 If more than one variable with the same name exists,
2242 the value of each of them will be printed on a separate line.
2245 @item set @var{variable} @var{value}
2246 Set configuration variable @var{variable} to the given @var{value}.
2247 All previously existing configuration variables with the same name are removed.
2248 To set a variable for a specific host, use the notation @var{host}.@var{variable}.
2251 @item add @var{variable} @var{value}
2252 As above, but without removing any previously existing configuration variables.
2255 @item del @var{variable} [@var{value}]
2256 Remove configuration variables with the same name and @var{value}.
2257 If no @var{value} is given, all configuration variables with the same name will be removed.
2260 @item edit @var{filename}
2261 Start an editor for the given configuration file.
2262 You do not need to specify the full path to the file.
2266 Export the host configuration file of the local node to standard output.
2270 Export all host configuration files to standard output.
2273 @item import [--force]
2274 Import host configuration file(s) generated by the tinc export command from standard input.
2275 Already existing host configuration files are not overwritten unless the option --force is used.
2278 @item exchange [--force]
2279 The same as export followed by import.
2281 @cindex exchange-all
2282 @item exchange-all [--force]
2283 The same as export-all followed by import.
2286 @item invite @var{name}
2287 Prepares an invitation for a new node with the given @var{name},
2288 and prints a short invitation URL that can be used with the join command.
2291 @item join [@var{URL}]
2292 Join an existing VPN using an invitation URL created using the invite command.
2293 If no @var{URL} is given, it will be read from standard input.
2296 @item start [tincd options]
2297 Start @samp{tincd}, optionally with the given extra options.
2304 @item restart [tincd options]
2305 Restart @samp{tincd}, optionally with the given extra options.
2309 Partially rereads configuration files. Connections to hosts whose host
2310 config files are removed are closed. New outgoing connections specified
2311 in @file{tinc.conf} will be made.
2315 Shows the PID of the currently running @samp{tincd}.
2317 @cindex generate-keys
2318 @item generate-keys [@var{bits}]
2319 Generate both RSA and ECDSA keypairs (see below) and exit.
2320 tinc will ask where you want to store the files, but will default to the
2321 configuration directory (you can use the -c or -n option).
2323 @cindex generate-ecdsa-keys
2324 @item generate-ecdsa-keys
2325 Generate public/private ECDSA keypair and exit.
2327 @cindex generate-rsa-keys
2328 @item generate-rsa-keys [@var{bits}]
2329 Generate public/private RSA keypair and exit. If @var{bits} is omitted, the
2330 default length will be 2048 bits. When saving keys to existing files, tinc
2331 will not delete the old keys; you have to remove them manually.
2334 @item dump [reachable] nodes
2335 Dump a list of all known nodes in the VPN.
2336 If the reachable keyword is used, only lists reachable nodes.
2339 Dump a list of all known connections in the VPN.
2342 Dump a list of all known subnets in the VPN.
2344 @item dump connections
2345 Dump a list of all meta connections with ourself.
2348 @item dump graph | digraph
2349 Dump a graph of the VPN in dotty format.
2350 Nodes are colored according to their reachability:
2351 red nodes are unreachable, orange nodes are indirectly reachable, green nodes are directly reachable.
2352 Black nodes are either directly or indirectly reachable, but direct reachability has not been tried yet.
2355 @item info @var{node} | @var{subnet} | @var{address}
2356 Show information about a particular @var{node}, @var{subnet} or @var{address}.
2357 If an @var{address} is given, any matching subnet will be shown.
2361 Purges all information remembered about unreachable nodes.
2364 @item debug @var{level}
2365 Sets debug level to @var{level}.
2368 @item log [@var{level}]
2369 Capture log messages from a running tinc daemon.
2370 An optional debug level can be given that will be applied only for log messages sent to tinc.
2374 Forces tinc to try to connect to all uplinks immediately.
2375 Usually tinc attempts to do this itself,
2376 but increases the time it waits between the attempts each time it failed,
2377 and if tinc didn't succeed to connect to an uplink the first time after it started,
2378 it defaults to the maximum time of 15 minutes.
2381 @item disconnect @var{node}
2382 Closes the meta connection with the given @var{node}.
2386 If tinc is compiled with libcurses support, this will display live traffic statistics for all the known nodes,
2387 similar to the UNIX top command.
2388 See below for more information.
2392 Dump VPN traffic going through the local tinc node in pcap-savefile format to standard output,
2393 from where it can be redirected to a file or piped through a program that can parse it directly,
2398 @c ==================================================================
2400 @section tinc examples
2402 Examples of some commands:
2405 tinc -n vpn dump graph | circo -Txlib
2406 tinc -n vpn pcap | tcpdump -r -
2410 Examples of changing the configuration using tinc:
2413 tinc -n vpn init foo
2414 tinc -n vpn add Subnet 192.168.1.0/24
2415 tinc -n vpn add bar.Address bar.example.com
2416 tinc -n vpn add ConnectTo bar
2417 tinc -n vpn export | gpg --clearsign | mail -s "My config" vpnmaster@@example.com
2420 @c ==================================================================
2425 The top command connects to a running tinc daemon and repeatedly queries its per-node traffic counters.
2426 It displays a list of all the known nodes in the left-most column,
2427 and the amount of bytes and packets read from and sent to each node in the other columns.
2428 By default, the information is updated every second.
2429 The behaviour of the top command can be changed using the following keys:
2434 Change the interval between updates.
2435 After pressing the @key{s} key, enter the desired interval in seconds, followed by enter.
2436 Fractional seconds are honored.
2437 Intervals lower than 0.1 seconds are not allowed.
2440 Toggle between displaying current traffic rates (in packets and bytes per second)
2441 and cummulative traffic (total packets and bytes since the tinc daemon started).
2444 Sort the list of nodes by name.
2447 Sort the list of nodes by incoming amount of bytes.
2450 Sort the list of nodes by incoming amount of packets.
2453 Sort the list of nodes by outgoing amount of bytes.
2456 Sort the list of nodes by outgoing amount of packets.
2459 Sort the list of nodes by sum of incoming and outgoing amount of bytes.
2462 Sort the list of nodes by sum of incoming and outgoing amount of packets.
2465 Show amount of traffic in bytes.
2468 Show amount of traffic in kilobytes.
2471 Show amount of traffic in megabytes.
2474 Show amount of traffic in gigabytes.
2482 @c ==================================================================
2483 @node Technical information
2484 @chapter Technical information
2489 * The meta-protocol::
2494 @c ==================================================================
2495 @node The connection
2496 @section The connection
2499 Tinc is a daemon that takes VPN data and transmit that to another host
2500 computer over the existing Internet infrastructure.
2504 * The meta-connection::
2508 @c ==================================================================
2509 @node The UDP tunnel
2510 @subsection The UDP tunnel
2512 @cindex virtual network device
2514 The data itself is read from a character device file, the so-called
2515 @emph{virtual network device}. This device is associated with a network
2516 interface. Any data sent to this interface can be read from the device,
2517 and any data written to the device gets sent from the interface.
2518 There are two possible types of virtual network devices:
2519 `tun' style, which are point-to-point devices which can only handle IPv4 and/or IPv6 packets,
2520 and `tap' style, which are Ethernet devices and handle complete Ethernet frames.
2522 So when tinc reads an Ethernet frame from the device, it determines its
2523 type. When tinc is in it's default routing mode, it can handle IPv4 and IPv6
2524 packets. Depending on the Subnet lines, it will send the packets off to their destination IP address.
2525 In the `switch' and `hub' mode, tinc will use broadcasts and MAC address discovery
2526 to deduce the destination of the packets.
2527 Since the latter modes only depend on the link layer information,
2528 any protocol that runs over Ethernet is supported (for instance IPX and Appletalk).
2529 However, only `tap' style devices provide this information.
2531 After the destination has been determined,
2532 the packet will be compressed (optionally),
2533 a sequence number will be added to the packet,
2534 the packet will then be encrypted
2535 and a message authentication code will be appended.
2537 @cindex encapsulating
2539 When that is done, time has come to actually transport the
2540 packet to the destination computer. We do this by sending the packet
2541 over an UDP connection to the destination host. This is called
2542 @emph{encapsulating}, the VPN packet (though now encrypted) is
2543 encapsulated in another IP datagram.
2545 When the destination receives this packet, the same thing happens, only
2546 in reverse. So it checks the message authentication code, decrypts the contents of the UDP datagram,
2547 checks the sequence number
2548 and writes the decrypted information to its own virtual network device.
2550 If the virtual network device is a `tun' device (a point-to-point tunnel),
2551 there is no problem for the kernel to accept a packet.
2552 However, if it is a `tap' device (this is the only available type on FreeBSD),
2553 the destination MAC address must match that of the virtual network interface.
2554 If tinc is in it's default routing mode, ARP does not work, so the correct destination MAC
2555 can not be known by the sending host.
2556 Tinc solves this by letting the receiving end detect the MAC address of its own virtual network interface
2557 and overwriting the destination MAC address of the received packet.
2559 In switch or hub modes ARP does work so the sender already knows the correct destination MAC address.
2560 In those modes every interface should have a unique MAC address, so make sure they are not the same.
2561 Because switch and hub modes rely on MAC addresses to function correctly,
2562 these modes cannot be used on the following operating systems which don't have a `tap' style virtual network device:
2563 OpenBSD, NetBSD, Darwin and Solaris.
2566 @c ==================================================================
2567 @node The meta-connection
2568 @subsection The meta-connection
2570 Having only a UDP connection available is not enough. Though suitable
2571 for transmitting data, we want to be able to reliably send other
2572 information, such as routing and session key information to somebody.
2575 TCP is a better alternative, because it already contains protection
2576 against information being lost, unlike UDP.
2578 So we establish two connections. One for the encrypted VPN data, and one
2579 for other information, the meta-data. Hence, we call the second
2580 connection the meta-connection. We can now be sure that the
2581 meta-information doesn't get lost on the way to another computer.
2583 @cindex data-protocol
2584 @cindex meta-protocol
2585 Like with any communication, we must have a protocol, so that everybody
2586 knows what everything stands for, and how she should react. Because we
2587 have two connections, we also have two protocols. The protocol used for
2588 the UDP data is the ``data-protocol,'' the other one is the
2591 The reason we don't use TCP for both protocols is that UDP is much
2592 better for encapsulation, even while it is less reliable. The real
2593 problem is that when TCP would be used to encapsulate a TCP stream
2594 that's on the private network, for every packet sent there would be
2595 three ACKs sent instead of just one. Furthermore, if there would be
2596 a timeout, both TCP streams would sense the timeout, and both would
2597 start re-sending packets.
2600 @c ==================================================================
2601 @node The meta-protocol
2602 @section The meta-protocol
2604 The meta protocol is used to tie all tinc daemons together, and
2605 exchange information about which tinc daemon serves which virtual
2608 The meta protocol consists of requests that can be sent to the other
2609 side. Each request has a unique number and several parameters. All
2610 requests are represented in the standard ASCII character set. It is
2611 possible to use tools such as telnet or netcat to connect to a tinc
2612 daemon started with the --bypass-security option
2613 and to read and write requests by hand, provided that one
2614 understands the numeric codes sent.
2616 The authentication scheme is described in @ref{Security}. After a
2617 successful authentication, the server and the client will exchange all the
2618 information about other tinc daemons and subnets they know of, so that both
2619 sides (and all the other tinc daemons behind them) have their information
2626 ------------------------------------------------------------------
2627 ADD_EDGE node1 node2 21.32.43.54 655 222 0
2628 | | | | | +-> options
2629 | | | | +----> weight
2630 | | | +--------> UDP port of node2
2631 | | +----------------> real address of node2
2632 | +-------------------------> name of destination node
2633 +-------------------------------> name of source node
2635 ADD_SUBNET node 192.168.1.0/24
2636 | | +--> prefixlength
2637 | +--------> network address
2638 +------------------> owner of this subnet
2639 ------------------------------------------------------------------
2642 The ADD_EDGE messages are to inform other tinc daemons that a connection between
2643 two nodes exist. The address of the destination node is available so that
2644 VPN packets can be sent directly to that node.
2646 The ADD_SUBNET messages inform other tinc daemons that certain subnets belong
2647 to certain nodes. tinc will use it to determine to which node a VPN packet has
2654 ------------------------------------------------------------------
2655 DEL_EDGE node1 node2
2656 | +----> name of destination node
2657 +----------> name of source node
2659 DEL_SUBNET node 192.168.1.0/24
2660 | | +--> prefixlength
2661 | +--------> network address
2662 +------------------> owner of this subnet
2663 ------------------------------------------------------------------
2666 In case a connection between two daemons is closed or broken, DEL_EDGE messages
2667 are sent to inform the other daemons of that fact. Each daemon will calculate a
2668 new route to the the daemons, or mark them unreachable if there isn't any.
2675 ------------------------------------------------------------------
2676 REQ_KEY origin destination
2677 | +--> name of the tinc daemon it wants the key from
2678 +----------> name of the daemon that wants the key
2680 ANS_KEY origin destination 4ae0b0a82d6e0078 91 64 4
2681 | | \______________/ | | +--> MAC length
2682 | | | | +-----> digest algorithm
2683 | | | +--------> cipher algorithm
2684 | | +--> 128 bits key
2685 | +--> name of the daemon that wants the key
2686 +----------> name of the daemon that uses this key
2689 +--> daemon that has changed it's packet key
2690 ------------------------------------------------------------------
2693 The keys used to encrypt VPN packets are not sent out directly. This is
2694 because it would generate a lot of traffic on VPNs with many daemons, and
2695 chances are that not every tinc daemon will ever send a packet to every
2696 other daemon. Instead, if a daemon needs a key it sends a request for it
2697 via the meta connection of the nearest hop in the direction of the
2704 ------------------------------------------------------------------
2707 ------------------------------------------------------------------
2710 There is also a mechanism to check if hosts are still alive. Since network
2711 failures or a crash can cause a daemon to be killed without properly
2712 shutting down the TCP connection, this is necessary to keep an up to date
2713 connection list. PINGs are sent at regular intervals, except when there
2714 is also some other traffic. A little bit of salt (random data) is added
2715 with each PING and PONG message, to make sure that long sequences of PING/PONG
2716 messages without any other traffic won't result in known plaintext.
2718 This basically covers what is sent over the meta connection by tinc.
2721 @c ==================================================================
2727 Tinc got its name from ``TINC,'' short for @emph{There Is No Cabal}; the
2728 alleged Cabal was/is an organisation that was said to keep an eye on the
2729 entire Internet. As this is exactly what you @emph{don't} want, we named
2730 the tinc project after TINC.
2733 But in order to be ``immune'' to eavesdropping, you'll have to encrypt
2734 your data. Because tinc is a @emph{Secure} VPN (SVPN) daemon, it does
2735 exactly that: encrypt.
2736 However, encryption in itself does not prevent an attacker from modifying the encrypted data.
2737 Therefore, tinc also authenticates the data.
2738 Finally, tinc uses sequence numbers (which themselves are also authenticated) to prevent an attacker from replaying valid packets.
2740 Since version 1.1pre3, tinc has two protocols used to protect your data; the legacy protocol, and the new Simple Peer-to-Peer Security (SPTPS) protocol.
2741 The SPTPS protocol is designed to address some weaknesses in the legacy protocol.
2742 The new authentication protocol is used when two nodes connect to each other that both have the ExperimentalProtocol option set to yes,
2743 otherwise the legacy protocol will be used.
2746 * Legacy authentication protocol::
2747 * Simple Peer-to-Peer Security::
2748 * Encryption of network packets::
2753 @c ==================================================================
2754 @node Legacy authentication protocol
2755 @subsection Legacy authentication protocol
2757 @cindex legacy authentication protocol
2766 --------------------------------------------------------------------------
2767 client <attempts connection>
2769 server <accepts connection>
2771 client ID client 17.2
2772 | | +-> minor protocol version
2773 | +----> major protocol version
2774 +--------> name of tinc daemon
2776 server ID server 17.2
2777 | | +-> minor protocol version
2778 | +----> major protocol version
2779 +--------> name of tinc daemon
2781 client META_KEY 94 64 0 0 5f0823a93e35b69e...7086ec7866ce582b
2782 | | | | \_________________________________/
2783 | | | | +-> RSAKEYLEN bits totally random string S1,
2784 | | | | encrypted with server's public RSA key
2785 | | | +-> compression level
2786 | | +---> MAC length
2787 | +------> digest algorithm NID
2788 +---------> cipher algorithm NID
2790 server META_KEY 94 64 0 0 6ab9c1640388f8f0...45d1a07f8a672630
2791 | | | | \_________________________________/
2792 | | | | +-> RSAKEYLEN bits totally random string S2,
2793 | | | | encrypted with client's public RSA key
2794 | | | +-> compression level
2795 | | +---> MAC length
2796 | +------> digest algorithm NID
2797 +---------> cipher algorithm NID
2798 --------------------------------------------------------------------------
2801 The protocol allows each side to specify encryption algorithms and parameters,
2802 but in practice they are always fixed, since older versions of tinc did not
2803 allow them to be different from the default values. The cipher is always
2804 Blowfish in OFB mode, the digest is SHA1, but the MAC length is zero and no
2805 compression is used.
2809 @item the client will symmetrically encrypt outgoing traffic using S1
2810 @item the server will symmetrically encrypt outgoing traffic using S2
2814 --------------------------------------------------------------------------
2815 client CHALLENGE da02add1817c1920989ba6ae2a49cecbda0
2816 \_________________________________/
2817 +-> CHALLEN bits totally random string H1
2819 server CHALLENGE 57fb4b2ccd70d6bb35a64c142f47e61d57f
2820 \_________________________________/
2821 +-> CHALLEN bits totally random string H2
2823 client CHAL_REPLY 816a86
2824 +-> 160 bits SHA1 of H2
2826 server CHAL_REPLY 928ffe
2827 +-> 160 bits SHA1 of H1
2829 After the correct challenge replies are received, both ends have proved
2830 their identity. Further information is exchanged.
2832 client ACK 655 123 0
2834 | +----> estimated weight
2835 +--------> listening port of client
2837 server ACK 655 321 0
2839 | +----> estimated weight
2840 +--------> listening port of server
2841 --------------------------------------------------------------------------
2844 This legacy authentication protocol has several weaknesses, pointed out by security export Peter Gutmann.
2845 First, data is encrypted with RSA without padding.
2846 Padding schemes are designed to prevent attacks when the size of the plaintext is not equal to the size of the RSA key.
2847 Tinc always encrypts random nonces that have the same size as the RSA key, so we do not believe this leads to a break of the security.
2848 There might be timing or other side-channel attacks against RSA encryption and decryption, tinc does not employ any protection against those.
2849 Furthermore, both sides send identical messages to each other, there is no distinction between server and client,
2850 which could make a MITM attack easier.
2851 However, no exploit is known in which a third party who is not already trusted by other nodes in the VPN could gain access.
2852 Finally, the RSA keys are used to directly encrypt the session keys, which means that if the RSA keys are compromised, it is possible to decrypt all previous VPN traffic.
2853 In other words, the legacy protocol does not provide perfect forward secrecy.
2855 @c ==================================================================
2856 @node Simple Peer-to-Peer Security
2857 @subsection Simple Peer-to-Peer Security
2860 The SPTPS protocol is designed to address the weaknesses in the legacy protocol.
2861 SPTPS is based on TLS 1.2, but has been simplified: there is no support for exchanging public keys, and there is no cipher suite negotiation.
2862 Instead, SPTPS always uses a very strong cipher suite:
2863 peers authenticate each other using 521 bits ECC keys,
2864 Diffie-Hellman using ephemeral 521 bits ECC keys is used to provide perfect forward secrecy (PFS),
2865 AES-256-CTR is used for encryption, and HMAC-SHA-256 for message authentication.
2867 Similar to TLS, messages are split up in records.
2868 A complete logical record contains the following information:
2871 @item uint32_t seqno (network byte order)
2872 @item uint16_t length (network byte order)
2874 @item opaque data[length]
2875 @item opaque hmac[HMAC_SIZE] (HMAC over all preceding fields)
2878 Depending on whether SPTPS records are sent via TCP or UDP, either the seqno or the length field is omitted on the wire
2879 (but they are still included in the calculation of the HMAC);
2880 for TCP packets are guaranteed to arrive in-order so we can infer the seqno, but packets can be split or merged, so we still need the length field to determine the boundaries between records;
2881 for UDP packets we know that there is exactly one record per packet, and we know the length of a packet, but packets can be dropped, duplicated and/or reordered, so we need to include the seqno.
2883 The type field is used to distinguish between application records or handshake records.
2884 Types 0 to 127 are application records, type 128 is a handshake record, and types 129 to 255 are reserved.
2886 Before the initial handshake, no fields are encrypted, and the HMAC field is not present.
2887 After the authentication handshake, the length (if present), type and data fields are encrypted, and the HMAC field is present.
2888 For UDP packets, the seqno field is not encrypted, as it is used to determine the value of the counter used for encryption.
2890 The authentication consists of an exchange of Key EXchange, SIGnature and ACKnowledge messages, transmitted using type 128 records.
2896 ---------------------
2902 ...encrypt and HMAC using session keys from now on...
2909 ...key renegotiation starts here...
2918 ...encrypt and HMAC using new session keys from now on...
2924 ---------------------
2927 Note that the responder does not need to wait before it receives the first KEX message,
2928 it can immediately send its own once it has accepted an incoming connection.
2930 Key EXchange message:
2933 @item uint8_t kex_version (always 0 in this version of SPTPS)
2934 @item opaque nonce[32] (random number)
2935 @item opaque ecdh_key[ECDH_SIZE]
2941 @item opaque ecdsa_signature[ECDSA_SIZE]
2944 ACKnowledge message:
2947 @item empty (only sent after key renegotiation)
2953 @item At the start, both peers generate a random nonce and an Elliptic Curve public key and send it to the other in the KEX message.
2954 @item After receiving the other's KEX message, both KEX messages are concatenated (see below),
2955 and the result is signed using ECDSA.
2956 The result is sent to the other.
2957 @item After receiving the other's SIG message, the signature is verified.
2958 If it is correct, the shared secret is calculated from the public keys exchanged in the KEX message using the Elliptic Curve Diffie-Helman algorithm.
2959 @item The shared secret key is expanded using a PRF.
2960 Both nonces and the application specific label are also used as input for the PRF.
2961 @item An ACK message is sent only when doing key renegotiation, and is sent using the old encryption keys.
2962 @item The expanded key is used to key the encryption and HMAC algorithms.
2965 The signature is calculated over this string:
2968 @item uint8_t initiator (0 = local peer, 1 = remote peer is initiator)
2969 @item opaque remote_kex_message[1 + 32 + ECDH_SIZE]
2970 @item opaque local_kex_message[1 + 32 + ECDH_SIZE]
2971 @item opaque label[label_length]
2974 The PRF is calculated as follows:
2977 @item A HMAC using SHA512 is used, the shared secret is used as the key.
2978 @item For each block of 64 bytes, a HMAC is calculated. For block n: hmac[n] =
2979 HMAC_SHA512(hmac[n - 1] + seed)
2980 @item For the first block (n = 1), hmac[0] is given by HMAC_SHA512(zeroes + seed),
2981 where zeroes is a block of 64 zero bytes.
2984 The seed is as follows:
2987 @item const char[13] "key expansion"
2988 @item opaque responder_nonce[32]
2989 @item opaque initiator_nonce[32]
2990 @item opaque label[label_length]
2993 The expanded key is used as follows:
2996 @item opaque responder_cipher_key[CIPHER_KEYSIZE]
2997 @item opaque responder_digest_key[DIGEST_KEYSIZE]
2998 @item opaque initiator_cipher_key[CIPHER_KEYSIZE]
2999 @item opaque initiator_digest_key[DIGEST_KEYSIZE]
3002 Where initiator_cipher_key is the key used by session initiator to encrypt
3003 messages sent to the responder.
3005 When using 521 bits EC keys, the AES-256-CTR cipher and HMAC-SHA-256 digest algorithm,
3006 the sizes are as follows:
3009 ECDH_SIZE: 67 (= ceil(521/8) + 1)
3010 ECDSA_SIZE: 141 (= 2 * ceil(521/8) + 9)
3011 CIPHER_KEYSIZE: 48 (= 256/8 + 128/8)
3012 DIGEST_KEYSIZE: 32 (= 256/8)
3015 Note that the cipher key also includes the initial value for the counter.
3017 @c ==================================================================
3018 @node Encryption of network packets
3019 @subsection Encryption of network packets
3022 A data packet can only be sent if the encryption key is known to both
3023 parties, and the connection is activated. If the encryption key is not
3024 known, a request is sent to the destination using the meta connection
3028 The UDP packets can be either encrypted with the legacy protocol or with SPTPS.
3029 In case of the legacy protocol, the UDP packet containing the network packet from the VPN has the following layout:
3032 ... | IP header | UDP header | seqno | VPN packet | MAC | UDP trailer
3033 \___________________/\_____/
3035 V +---> digest algorithm
3036 Encrypted with symmetric cipher
3042 So, the entire VPN packet is encrypted using a symmetric cipher, including a 32 bits
3043 sequence number that is added in front of the actual VPN packet, to act as a unique
3044 IV for each packet and to prevent replay attacks. A message authentication code
3045 is added to the UDP packet to prevent alteration of packets.
3046 Tinc by default encrypts network packets using Blowfish with 128 bit keys in CBC mode
3047 and uses 4 byte long message authentication codes to make sure
3048 eavesdroppers cannot get and cannot change any information at all from the
3049 packets they can intercept. The encryption algorithm and message authentication
3050 algorithm can be changed in the configuration. The length of the message
3051 authentication codes is also adjustable. The length of the key for the
3052 encryption algorithm is always the default length used by OpenSSL.
3054 The SPTPS protocol is described in @ref{Simple Peer-to-Peer Security}.
3055 For comparison, this is how SPTPS UDP packets look:
3058 ... | IP header | UDP header | seqno | type | VPN packet | MAC | UDP trailer
3059 \__________________/\_____/
3061 V +---> digest algorithm
3062 Encrypted with symmetric cipher
3065 The difference is that the seqno is not encrypted, since the encryption cipher is used in CTR mode,
3066 and therefore the seqno must be known before the packet can be decrypted.
3067 Furthermore, the MAC is never truncated.
3068 The SPTPS protocol always uses the AES-256-CTR cipher and HMAC-SHA-256 digest,
3069 this cannot be changed.
3072 @c ==================================================================
3073 @node Security issues
3074 @subsection Security issues
3076 In August 2000, we discovered the existence of a security hole in all versions
3077 of tinc up to and including 1.0pre2. This had to do with the way we exchanged
3078 keys. Since then, we have been working on a new authentication scheme to make
3079 tinc as secure as possible. The current version uses the OpenSSL library and
3080 uses strong authentication with RSA keys.
3082 On the 29th of December 2001, Jerome Etienne posted a security analysis of tinc
3083 1.0pre4. Due to a lack of sequence numbers and a message authentication code
3084 for each packet, an attacker could possibly disrupt certain network services or
3085 launch a denial of service attack by replaying intercepted packets. The current
3086 version adds sequence numbers and message authentication codes to prevent such
3089 On the 15th of September 2003, Peter Gutmann posted a security analysis of tinc
3090 1.0.1. He argues that the 32 bit sequence number used by tinc is not a good IV,
3091 that tinc's default length of 4 bytes for the MAC is too short, and he doesn't
3092 like tinc's use of RSA during authentication. We do not know of a security hole
3093 in the legacy protocol of tinc, but it is not as strong as TLS or IPsec.
3095 This version of tinc comes with an improved protocol, called Simple Peer-to-Peer Security,
3096 which aims to be as strong as TLS with one of the strongest cipher suites.
3098 Cryptography is a hard thing to get right. We cannot make any
3099 guarantees. Time, review and feedback are the only things that can
3100 prove the security of any cryptographic product. If you wish to review
3101 tinc or give us feedback, you are stronly encouraged to do so.
3104 @c ==================================================================
3105 @node Platform specific information
3106 @chapter Platform specific information
3109 * Interface configuration::
3113 @c ==================================================================
3114 @node Interface configuration
3115 @section Interface configuration
3117 When configuring an interface, one normally assigns it an address and a
3118 netmask. The address uniquely identifies the host on the network attached to
3119 the interface. The netmask, combined with the address, forms a subnet. It is
3120 used to add a route to the routing table instructing the kernel to send all
3121 packets which fall into that subnet to that interface. Because all packets for
3122 the entire VPN should go to the virtual network interface used by tinc, the
3123 netmask should be such that it encompasses the entire VPN.
3127 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
3129 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
3130 @item Linux iproute2
3131 @tab @code{ip addr add} @var{address}@code{/}@var{prefixlength} @code{dev} @var{interface}
3133 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
3135 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
3137 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
3139 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
3140 @item Darwin (MacOS/X)
3141 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
3143 @tab @code{netsh interface ip set address} @var{interface} @code{static} @var{address} @var{netmask}
3148 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
3150 @tab @code{ifconfig} @var{interface} @code{add} @var{address}@code{/}@var{prefixlength}
3152 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
3154 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
3156 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
3158 @tab @code{ifconfig} @var{interface} @code{inet6 plumb up}
3160 @tab @code{ifconfig} @var{interface} @code{inet6 addif} @var{address} @var{address}
3161 @item Darwin (MacOS/X)
3162 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
3164 @tab @code{netsh interface ipv6 add address} @var{interface} @code{static} @var{address}/@var{prefixlength}
3167 On some platforms, when running tinc in switch mode, the VPN interface must be set to tap mode with an ifconfig command:
3169 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
3171 @tab @code{ifconfig} @var{interface} @code{link0}
3174 On Linux, it is possible to create a persistent tun/tap interface which will
3175 continue to exist even if tinc quit, although this is normally not required.
3176 It can be useful to set up a tun/tap interface owned by a non-root user, so
3177 tinc can be started without needing any root privileges at all.
3179 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
3181 @tab @code{ip tuntap add dev} @var{interface} @code{mode} @var{tun|tap} @code{user} @var{username}
3184 @c ==================================================================
3188 In some cases it might be necessary to add more routes to the virtual network
3189 interface. There are two ways to indicate which interface a packet should go
3190 to, one is to use the name of the interface itself, another way is to specify
3191 the (local) address that is assigned to that interface (@var{local_address}). The
3192 former way is unambiguous and therefore preferable, but not all platforms
3195 Adding routes to IPv4 subnets:
3197 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
3199 @tab @code{route add -net} @var{network_address} @code{netmask} @var{netmask} @var{interface}
3200 @item Linux iproute2
3201 @tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
3203 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
3205 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
3207 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
3209 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
3210 @item Darwin (MacOS/X)
3211 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
3213 @tab @code{netsh routing ip add persistentroute} @var{network_address} @var{netmask} @var{interface} @var{local_address}
3216 Adding routes to IPv6 subnets:
3218 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
3220 @tab @code{route add -A inet6} @var{network_address}@code{/}@var{prefixlength} @var{interface}
3221 @item Linux iproute2
3222 @tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
3224 @tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
3226 @tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
3228 @tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
3230 @tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
3231 @item Darwin (MacOS/X)
3234 @tab @code{netsh interface ipv6 add route} @var{network address}/@var{prefixlength} @var{interface}
3238 @c ==================================================================
3244 * Contact information::
3249 @c ==================================================================
3250 @node Contact information
3251 @section Contact information
3254 Tinc's website is at @url{http://www.tinc-vpn.org/},
3255 this server is located in the Netherlands.
3258 We have an IRC channel on the FreeNode and OFTC IRC networks. Connect to
3259 @uref{http://www.freenode.net/, irc.freenode.net}
3261 @uref{http://www.oftc.net/, irc.oftc.net}
3262 and join channel #tinc.
3265 @c ==================================================================
3270 @item Ivo Timmermans (zarq)
3271 @item Guus Sliepen (guus) (@email{guus@@tinc-vpn.org})
3274 We have received a lot of valuable input from users. With their help,
3275 tinc has become the flexible and robust tool that it is today. We have
3276 composed a list of contributions, in the file called @file{THANKS} in
3277 the source distribution.
3280 @c ==================================================================
3282 @unnumbered Concept Index
3284 @c ==================================================================
3288 @c ==================================================================