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{} 1998-2012 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.
35 @subtitle Setting up a Virtual Private Network with tinc
36 @author Ivo Timmermans and Guus Sliepen
39 @vskip 0pt plus 1filll
40 This is the info manual for @value{PACKAGE} version @value{VERSION}, a Virtual Private Network daemon.
42 Copyright @copyright{} 1998-2012 Ivo Timmermans,
43 Guus Sliepen <guus@@tinc-vpn.org> and
44 Wessel Dankers <wsl@@tinc-vpn.org>.
46 Permission is granted to make and distribute verbatim copies of this
47 manual provided the copyright notice and this permission notice are
48 preserved on all copies.
50 Permission is granted to copy and distribute modified versions of this
51 manual under the conditions for verbatim copying, provided that the
52 entire resulting derived work is distributed under the terms of a
53 permission notice identical to this one.
58 @c ==================================================================
68 * Technical information::
69 * Platform specific information::
71 * Concept Index:: All used terms explained
75 @c ==================================================================
80 Tinc is a Virtual Private Network (VPN) daemon that uses tunneling and
81 encryption to create a secure private network between hosts on the
84 Because the tunnel appears to the IP level network code as a normal
85 network device, there is no need to adapt any existing software.
86 The encrypted tunnels allows VPN sites to share information with each other
87 over the Internet without exposing any information to others.
89 This document is the manual for tinc. Included are chapters on how to
90 configure your computer to use tinc, as well as the configuration
91 process of tinc itself.
94 * Virtual Private Networks::
96 * Supported platforms::
99 @c ==================================================================
100 @node Virtual Private Networks
101 @section Virtual Private Networks
104 A Virtual Private Network or VPN is a network that can only be accessed
105 by a few elected computers that participate. This goal is achievable in
106 more than just one way.
109 Private networks can consist of a single stand-alone Ethernet LAN. Or
110 even two computers hooked up using a null-modem cable. In these cases,
112 obvious that the network is @emph{private}, no one can access it from the
113 outside. But if your computers are linked to the Internet, the network
114 is not private anymore, unless one uses firewalls to block all private
115 traffic. But then, there is no way to send private data to trusted
116 computers on the other end of the Internet.
119 This problem can be solved by using @emph{virtual} networks. Virtual
120 networks can live on top of other networks, but they use encapsulation to
121 keep using their private address space so they do not interfere with
122 the Internet. Mostly, virtual networks appear like a single LAN, even though
123 they can span the entire world. But virtual networks can't be secured
124 by using firewalls, because the traffic that flows through it has to go
125 through the Internet, where other people can look at it.
127 As is the case with either type of VPN, anybody could eavesdrop. Or
128 worse, alter data. Hence it's probably advisable to encrypt the data
129 that flows over the network.
131 When one introduces encryption, we can form a true VPN. Other people may
132 see encrypted traffic, but if they don't know how to decipher it (they
133 need to know the key for that), they cannot read the information that flows
134 through the VPN. This is what tinc was made for.
137 @c ==================================================================
142 I really don't quite remember what got us started, but it must have been
143 Guus' idea. He wrote a simple implementation (about 50 lines of C) that
144 used the ethertap device that Linux knows of since somewhere
145 about kernel 2.1.60. It didn't work immediately and he improved it a
146 bit. At this stage, the project was still simply called "vpnd".
148 Since then, a lot has changed---to say the least.
151 Tinc now supports encryption, it consists of a single daemon (tincd) for
152 both the receiving and sending end, it has become largely
153 runtime-configurable---in short, it has become a full-fledged
154 professional package.
156 @cindex traditional VPNs
158 Tinc also allows more than two sites to connect to eachother and form a single VPN.
159 Traditionally VPNs are created by making tunnels, which only have two endpoints.
160 Larger VPNs with more sites are created by adding more tunnels.
161 Tinc takes another approach: only endpoints are specified,
162 the software itself will take care of creating the tunnels.
163 This allows for easier configuration and improved scalability.
165 A lot can---and will be---changed. We have a number of things that we would like to
166 see in the future releases of tinc. Not everything will be available in
167 the near future. Our first objective is to make tinc work perfectly as
168 it stands, and then add more advanced features.
170 Meanwhile, we're always open-minded towards new ideas. And we're
174 @c ==================================================================
175 @node Supported platforms
176 @section Supported platforms
179 Tinc has been verified to work under Linux, FreeBSD, OpenBSD, NetBSD, MacOS/X (Darwin), Solaris, and Windows (both natively and in a Cygwin environment),
180 with various hardware architectures. These are some of the platforms
181 that are supported by the universal tun/tap device driver or other virtual network device drivers.
182 Without such a driver, tinc will most
183 likely compile and run, but it will not be able to send or receive data
187 For an up to date list of supported platforms, please check the list on
189 @uref{http://www.tinc-vpn.org/platforms}.
197 @c Preparing your system
204 @c ==================================================================
206 @chapter Preparations
208 This chapter contains information on how to prepare your system to
212 * Configuring the kernel::
217 @c ==================================================================
218 @node Configuring the kernel
219 @section Configuring the kernel
222 * Configuration of Linux kernels::
223 * Configuration of FreeBSD kernels::
224 * Configuration of OpenBSD kernels::
225 * Configuration of NetBSD kernels::
226 * Configuration of Solaris kernels::
227 * Configuration of Darwin (MacOS/X) kernels::
228 * Configuration of Windows::
232 @c ==================================================================
233 @node Configuration of Linux kernels
234 @subsection Configuration of Linux kernels
236 @cindex Universal tun/tap
237 For tinc to work, you need a kernel that supports the Universal tun/tap device.
238 Most distributions come with kernels that already support this.
239 Here are the options you have to turn on when configuring a new kernel:
242 Code maturity level options
243 [*] Prompt for development and/or incomplete code/drivers
244 Network device support
245 <M> Universal tun/tap device driver support
248 It's not necessary to compile this driver as a module, even if you are going to
249 run more than one instance of tinc.
251 If you decide to build the tun/tap driver as a kernel module, add these lines
252 to @file{/etc/modules.conf}:
255 alias char-major-10-200 tun
259 @c ==================================================================
260 @node Configuration of FreeBSD kernels
261 @subsection Configuration of FreeBSD kernels
263 For FreeBSD version 4.1 and higher, tun and tap drivers are included in the default kernel configuration.
264 Using tap devices is recommended.
267 @c ==================================================================
268 @node Configuration of OpenBSD kernels
269 @subsection Configuration of OpenBSD kernels
271 For OpenBSD version 2.9 and higher,
272 the tun driver is included in the default kernel configuration.
273 There is also a kernel patch from @uref{http://diehard.n-r-g.com/stuff/openbsd/}
274 which adds a tap device to OpenBSD which should work with tinc,
275 but with recent versions of OpenBSD,
276 a tun device can act as a tap device by setting the link0 option with ifconfig.
278 @c ==================================================================
279 @node Configuration of NetBSD kernels
280 @subsection Configuration of NetBSD kernels
282 For NetBSD version 1.5.2 and higher,
283 the tun driver is included in the default kernel configuration.
285 Tunneling IPv6 may not work on NetBSD's tun device.
288 @c ==================================================================
289 @node Configuration of Solaris kernels
290 @subsection Configuration of Solaris kernels
292 For Solaris 8 (SunOS 5.8) and higher,
293 the tun driver may or may not be included in the default kernel configuration.
294 If it isn't, the source can be downloaded from @uref{http://vtun.sourceforge.net/tun/}.
295 For x86 and sparc64 architectures, precompiled versions can be found at @uref{http://www.monkey.org/~dugsong/fragroute/}.
296 If the @file{net/if_tun.h} header file is missing, install it from the source package.
299 @c ==================================================================
300 @node Configuration of Darwin (MacOS/X) kernels
301 @subsection Configuration of Darwin (MacOS/X) kernels
303 Tinc on Darwin relies on a tunnel driver for its data acquisition from the kernel.
304 Tinc supports either the driver from @uref{http://tuntaposx.sourceforge.net/},
305 which supports both tun and tap style devices,
306 and also the driver from from @uref{http://chrisp.de/en/projects/tunnel.html}.
307 The former driver is recommended.
308 The tunnel driver must be loaded before starting tinc with the following command:
315 @c ==================================================================
316 @node Configuration of Windows
317 @subsection Configuration of Windows
319 You will need to install the latest TAP-Win32 driver from OpenVPN.
320 You can download it from @uref{http://openvpn.sourceforge.net}.
321 Using the Network Connections control panel,
322 configure the TAP-Win32 network interface in the same way as you would do from the tinc-up script,
323 as explained in the rest of the documentation.
326 @c ==================================================================
332 Before you can configure or build tinc, you need to have the OpenSSL,
333 zlib and lzo libraries installed on your system. If you try to configure tinc without
334 having them installed, configure will give you an error message, and stop.
343 @c ==================================================================
348 For all cryptography-related functions, tinc uses the functions provided
349 by the OpenSSL library.
351 If this library is not installed, you wil get an error when configuring
352 tinc for build. Support for running tinc without having OpenSSL
353 installed @emph{may} be added in the future.
355 You can use your operating system's package manager to install this if
356 available. Make sure you install the development AND runtime versions
359 If you have to install OpenSSL manually, you can get the source code
360 from @url{http://www.openssl.org/}. Instructions on how to configure,
361 build and install this package are included within the package. Please
362 make sure you build development and runtime libraries (which is the
365 If you installed the OpenSSL libraries from source, it may be necessary
366 to let configure know where they are, by passing configure one of the
367 --with-openssl-* parameters.
370 --with-openssl=DIR OpenSSL library and headers prefix
371 --with-openssl-include=DIR OpenSSL headers directory
372 (Default is OPENSSL_DIR/include)
373 --with-openssl-lib=DIR OpenSSL library directory
374 (Default is OPENSSL_DIR/lib)
378 @subsubheading License
381 The complete source code of tinc is covered by the GNU GPL version 2.
382 Since the license under which OpenSSL is distributed is not directly
383 compatible with the terms of the GNU GPL
384 @uref{http://www.openssl.org/support/faq.html#LEGAL2}, we
385 include an exemption to the GPL (see also the file COPYING.README) to allow
386 everyone to create a statically or dynamically linked executable:
389 This program is released under the GPL with the additional exemption
390 that compiling, linking, and/or using OpenSSL is allowed. You may
391 provide binary packages linked to the OpenSSL libraries, provided that
392 all other requirements of the GPL are met.
395 Since the LZO library used by tinc is also covered by the GPL,
396 we also present the following exemption:
399 Hereby I grant a special exception to the tinc VPN project
400 (http://www.tinc-vpn.org/) to link the LZO library with the OpenSSL library
401 (http://www.openssl.org).
403 Markus F.X.J. Oberhumer
407 @c ==================================================================
412 For the optional compression of UDP packets, tinc uses the functions provided
415 If this library is not installed, you wil get an error when configuring
416 tinc for build. Support for running tinc without having zlib
417 installed @emph{may} be added in the future.
419 You can use your operating system's package manager to install this if
420 available. Make sure you install the development AND runtime versions
423 If you have to install zlib manually, you can get the source code
424 from @url{http://www.gzip.org/zlib/}. Instructions on how to configure,
425 build and install this package are included within the package. Please
426 make sure you build development and runtime libraries (which is the
430 @c ==================================================================
435 Another form of compression is offered using the lzo library.
437 If this library is not installed, you wil get an error when configuring
438 tinc for build. Support for running tinc without having lzo
439 installed @emph{may} be added in the future.
441 You can use your operating system's package manager to install this if
442 available. Make sure you install the development AND runtime versions
445 If you have to install lzo manually, you can get the source code
446 from @url{http://www.oberhumer.com/opensource/lzo/}. Instructions on how to configure,
447 build and install this package are included within the package. Please
448 make sure you build development and runtime libraries (which is the
461 @c ==================================================================
463 @chapter Installation
465 If you use Debian, you may want to install one of the
466 precompiled packages for your system. These packages are equipped with
467 system startup scripts and sample configurations.
469 If you cannot use one of the precompiled packages, or you want to compile tinc
470 for yourself, you can use the source. The source is distributed under
471 the GNU General Public License (GPL). Download the source from the
472 @uref{http://www.tinc-vpn.org/download, download page}, which has
473 the checksums of these files listed; you may wish to check these with
474 md5sum before continuing.
476 Tinc comes in a convenient autoconf/automake package, which you can just
477 treat the same as any other package. Which is just untar it, type
478 `./configure' and then `make'.
479 More detailed instructions are in the file @file{INSTALL}, which is
480 included in the source distribution.
483 * Building and installing tinc::
488 @c ==================================================================
489 @node Building and installing tinc
490 @section Building and installing tinc
492 Detailed instructions on configuring the source, building tinc and installing tinc
493 can be found in the file called @file{INSTALL}.
495 @cindex binary package
496 If you happen to have a binary package for tinc for your distribution,
497 you can use the package management tools of that distribution to install tinc.
498 The documentation that comes along with your distribution will tell you how to do that.
501 * Darwin (MacOS/X) build environment::
502 * Cygwin (Windows) build environment::
503 * MinGW (Windows) build environment::
507 @c ==================================================================
508 @node Darwin (MacOS/X) build environment
509 @subsection Darwin (MacOS/X) build environment
511 In order to build tinc on Darwin, you need to install the MacOS/X Developer Tools
512 from @uref{http://developer.apple.com/tools/macosxtools.html} and
513 a recent version of Fink from @uref{http://fink.sourceforge.net/}.
515 After installation use fink to download and install the following packages:
516 autoconf25, automake, dlcompat, m4, openssl, zlib and lzo.
518 @c ==================================================================
519 @node Cygwin (Windows) build environment
520 @subsection Cygwin (Windows) build environment
522 If Cygwin hasn't already been installed, install it directly from
523 @uref{http://www.cygwin.com/}.
525 When tinc is compiled in a Cygwin environment, it can only be run in this environment,
526 but all programs, including those started outside the Cygwin environment, will be able to use the VPN.
527 It will also support all features.
529 @c ==================================================================
530 @node MinGW (Windows) build environment
531 @subsection MinGW (Windows) build environment
533 You will need to install the MinGW environment from @uref{http://www.mingw.org}.
535 When tinc is compiled using MinGW it runs natively under Windows,
536 it is not necessary to keep MinGW installed.
538 When detaching, tinc will install itself as a service,
539 which will be restarted automatically after reboots.
542 @c ==================================================================
544 @section System files
546 Before you can run tinc, you must make sure you have all the needed
547 files on your system.
555 @c ==================================================================
557 @subsection Device files
560 Most operating systems nowadays come with the necessary device files by default,
561 or they have a mechanism to create them on demand.
563 If you use Linux and do not have udev installed,
564 you may need to create the following device file if it does not exist:
567 mknod -m 600 /dev/net/tun c 10 200
571 @c ==================================================================
573 @subsection Other files
575 @subsubheading @file{/etc/networks}
577 You may add a line to @file{/etc/networks} so that your VPN will get a
578 symbolic name. For example:
584 @subsubheading @file{/etc/services}
587 You may add this line to @file{/etc/services}. The effect is that you
588 may supply a @samp{tinc} as a valid port number to some programs. The
589 number 655 is registered with the IANA.
594 # Ivo Timmermans <ivo@@tinc-vpn.org>
609 @c ==================================================================
611 @chapter Configuration
614 * Configuration introduction::
615 * Multiple networks::
616 * How connections work::
617 * Configuration files::
618 * Generating keypairs::
619 * Network interfaces::
620 * Example configuration::
623 @c ==================================================================
624 @node Configuration introduction
625 @section Configuration introduction
627 Before actually starting to configure tinc and editing files,
628 make sure you have read this entire section so you know what to expect.
629 Then, make it clear to yourself how you want to organize your VPN:
630 What are the nodes (computers running tinc)?
631 What IP addresses/subnets do they have?
632 What is the network mask of the entire VPN?
633 Do you need special firewall rules?
634 Do you have to set up masquerading or forwarding rules?
635 Do you want to run tinc in router mode or switch mode?
636 These questions can only be answered by yourself,
637 you will not find the answers in this documentation.
638 Make sure you have an adequate understanding of networks in general.
639 @cindex Network Administrators Guide
640 A good resource on networking is the
641 @uref{http://www.linuxdoc.org/LDP/nag2/, Linux Network Administrators Guide}.
643 If you have everything clearly pictured in your mind,
644 proceed in the following order:
645 First, generate the configuration files (@file{tinc.conf}, your host configuration file, @file{tinc-up} and perhaps @file{tinc-down}).
646 Then generate the keypairs.
647 Finally, distribute the host configuration files.
648 These steps are described in the subsections below.
651 @c ==================================================================
652 @node Multiple networks
653 @section Multiple networks
655 @cindex multiple networks
657 In order to allow you to run more than one tinc daemon on one computer,
658 for instance if your computer is part of more than one VPN,
659 you can assign a @var{netname} to your VPN.
660 It is not required if you only run one tinc daemon,
661 it doesn't even have to be the same on all the sites of your VPN,
662 but it is recommended that you choose one anyway.
664 We will asume you use a netname throughout this document.
665 This means that you call tincd with the -n argument,
666 which will assign a netname to this daemon.
668 The effect of this is that the daemon will set its configuration
669 root to @file{@value{sysconfdir}/tinc/@var{netname}/}, where @var{netname} is your argument to the -n
670 option. You'll notice that it appears in syslog as @file{tinc.@var{netname}}.
672 However, it is not strictly necessary that you call tinc with the -n
673 option. In this case, the network name would just be empty, and it will
674 be used as such. tinc now looks for files in @file{@value{sysconfdir}/tinc/}, instead of
675 @file{@value{sysconfdir}/tinc/@var{netname}/}; the configuration file should be @file{@value{sysconfdir}/tinc/tinc.conf},
676 and the host configuration files are now expected to be in @file{@value{sysconfdir}/tinc/hosts/}.
678 But it is highly recommended that you use this feature of tinc, because
679 it will be so much clearer whom your daemon talks to. Hence, we will
680 assume that you use it.
683 @c ==================================================================
684 @node How connections work
685 @section How connections work
687 When tinc starts up, it parses the command-line options and then
688 reads in the configuration file tinc.conf.
689 If it sees one or more `ConnectTo' values pointing to other tinc daemons in that file,
690 it will try to connect to those other daemons.
691 Whether this succeeds or not and whether `ConnectTo' is specified or not,
692 tinc will listen for incoming connection from other deamons.
693 If you did specify a `ConnectTo' value and the other side is not responding,
694 tinc will keep retrying.
695 This means that once started, tinc will stay running until you tell it to stop,
696 and failures to connect to other tinc daemons will not stop your tinc daemon
697 for trying again later.
698 This means you don't have to intervene if there are temporary network problems.
702 There is no real distinction between a server and a client in tinc.
703 If you wish, you can view a tinc daemon without a `ConnectTo' value as a server,
704 and one which does specify such a value as a client.
705 It does not matter if two tinc daemons have a `ConnectTo' value pointing to each other however.
708 @c ==================================================================
709 @node Configuration files
710 @section Configuration files
712 The actual configuration of the daemon is done in the file
713 @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf} and at least one other file in the directory
714 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/}.
716 These file consists of comments (lines started with a #) or assignments
723 The variable names are case insensitive, and any spaces, tabs, newlines
724 and carriage returns are ignored. Note: it is not required that you put
725 in the `=' sign, but doing so improves readability. If you leave it
726 out, remember to replace it with at least one space character.
728 The server configuration is complemented with host specific configuration (see
729 the next section). Although all host configuration options for the local node
730 listed in this document can also be put in
731 @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf}, it is recommended to
732 put host specific configuration options in the host configuration file, as this
733 makes it easy to exchange with other nodes.
735 In this section all valid variables are listed in alphabetical order.
736 The default value is given between parentheses,
737 other comments are between square brackets.
740 * Main configuration variables::
741 * Host configuration variables::
747 @c ==================================================================
748 @node Main configuration variables
749 @subsection Main configuration variables
752 @cindex AddressFamily
753 @item AddressFamily = <ipv4|ipv6|any> (any)
754 This option affects the address family of listening and outgoing sockets.
755 If any is selected, then depending on the operating system
756 both IPv4 and IPv6 or just IPv6 listening sockets will be created.
758 @cindex BindToAddress
759 @item BindToAddress = <@var{address}> [<@var{port}>] [experimental]
760 If your computer has more than one IPv4 or IPv6 address, tinc
761 will by default listen on all of them for incoming connections.
762 Multiple BindToAddress variables may be specified,
763 in which case listening sockets for each specified address are made.
765 If no @var{port} is specified, the socket will be bound to the port specified by the Port option,
766 or to port 655 if neither is given.
767 To only bind to a specific port but not to a specific address, use "*" for the @var{address}.
769 This option may not work on all platforms.
771 @cindex BindToInterface
772 @item BindToInterface = <@var{interface}> [experimental]
773 If you have more than one network interface in your computer, tinc will
774 by default listen on all of them for incoming connections. It is
775 possible to bind tinc to a single interface like eth0 or ppp0 with this
778 This option may not work on all platforms.
781 @item Broadcast = <yes | no> (yes) [experimental]
782 When disabled, tinc will drop all broadcast and multicast packets, in both router and switch mode.
785 @item ConnectTo = <@var{name}>
786 Specifies which other tinc daemon to connect to on startup.
787 Multiple ConnectTo variables may be specified,
788 in which case outgoing connections to each specified tinc daemon are made.
789 The names should be known to this tinc daemon
790 (i.e., there should be a host configuration file for the name on the ConnectTo line).
792 If you don't specify a host with ConnectTo,
793 tinc won't try to connect to other daemons at all,
794 and will instead just listen for incoming connections.
797 @item DecrementTTL = <yes | no> (yes)
798 When enabled, tinc will decrement the Time To Live field in IPv4 packets, or the Hop Limit field in IPv6 packets,
799 before forwarding a received packet to the virtual network device or to another node,
800 and will drop packets that have a TTL value of zero,
801 in which case it will send an ICMP Time Exceeded packet back.
804 @item Device = <@var{device}> (@file{/dev/tap0}, @file{/dev/net/tun} or other depending on platform)
805 The virtual network device to use.
806 Tinc will automatically detect what kind of device it is.
807 Note that you can only use one device per daemon.
808 Under Windows, use @var{Interface} instead of @var{Device}.
809 Note that you can only use one device per daemon.
810 See also @ref{Device files}.
813 @item DeviceType = <@var{type}> (platform dependent)
814 The type of the virtual network device.
815 Tinc will normally automatically select the right type of tun/tap interface, and this option should not be used.
816 However, this option can be used to select one of the special interface types, if support for them is compiled in.
821 Use a dummy interface.
822 No packets are ever read or written to a virtual network device.
823 Useful for testing, or when setting up a node that only forwards packets for other nodes.
827 Open a raw socket, and bind it to a pre-existing
828 @var{Interface} (eth0 by default).
829 All packets are read from this interface.
830 Packets received for the local node are written to the raw socket.
831 However, at least on Linux, the operating system does not process IP packets destined for the local host.
834 @item uml (not compiled in by default)
835 Create a UNIX socket with the filename specified by
836 @var{Device}, or @file{@value{localstatedir}/run/@var{netname}.umlsocket}
838 Tinc will wait for a User Mode Linux instance to connect to this socket.
841 @item vde (not compiled in by default)
842 Uses the libvdeplug library to connect to a Virtual Distributed Ethernet switch,
843 using the UNIX socket specified by
844 @var{Device}, or @file{@value{localstatedir}/run/vde.ctl}
848 Also, in case tinc does not seem to correctly interpret packets received from the virtual network device,
849 it can be used to change the way packets are interpreted:
852 @item tun (BSD and Linux)
854 Depending on the platform, this can either be with or without an address family header (see below).
857 @item tunnohead (BSD)
858 Set type to tun without an address family header.
859 Tinc will expect packets read from the virtual network device to start with an IP header.
860 On some platforms IPv6 packets cannot be read from or written to the device in this mode.
863 @item tunifhead (BSD)
864 Set type to tun with an address family header.
865 Tinc will expect packets read from the virtual network device
866 to start with a four byte header containing the address family,
867 followed by an IP header.
868 This mode should support both IPv4 and IPv6 packets.
870 @item tap (BSD and Linux)
872 Tinc will expect packets read from the virtual network device
873 to start with an Ethernet header.
877 @item DirectOnly = <yes|no> (no) [experimental]
878 When this option is enabled, packets that cannot be sent directly to the destination node,
879 but which would have to be forwarded by an intermediate node, are dropped instead.
880 When combined with the IndirectData option,
881 packets for nodes for which we do not have a meta connection with are also dropped.
884 @item Forwarding = <off|internal|kernel> (internal) [experimental]
885 This option selects the way indirect packets are forwarded.
889 Incoming packets that are not meant for the local node,
890 but which should be forwarded to another node, are dropped.
893 Incoming packets that are meant for another node are forwarded by tinc internally.
895 This is the default mode, and unless you really know you need another forwarding mode, don't change it.
898 Incoming packets are always sent to the TUN/TAP device, even if the packets are not for the local node.
899 This is less efficient, but allows the kernel to apply its routing and firewall rules on them,
900 and can also help debugging.
903 @cindex GraphDumpFile
904 @item GraphDumpFile = <@var{filename}> [experimental]
905 If this option is present,
906 tinc will dump the current network graph to the file @var{filename}
907 every minute, unless there were no changes to the graph.
908 The file is in a format that can be read by graphviz tools.
909 If @var{filename} starts with a pipe symbol |,
910 then the rest of the filename is interpreted as a shell command
911 that is executed, the graph is then sent to stdin.
914 @item Hostnames = <yes|no> (no)
915 This option selects whether IP addresses (both real and on the VPN)
916 should be resolved. Since DNS lookups are blocking, it might affect
917 tinc's efficiency, even stopping the daemon for a few seconds everytime
918 it does a lookup if your DNS server is not responding.
920 This does not affect resolving hostnames to IP addresses from the
924 @item Interface = <@var{interface}>
925 Defines the name of the interface corresponding to the virtual network device.
926 Depending on the operating system and the type of device this may or may not actually set the name of the interface.
927 Under Windows, this variable is used to select which network interface will be used.
928 If you specified a Device, this variable is almost always already correctly set.
930 @cindex LocalDiscovery
931 @item LocalDiscovery = <yes | no> (no) [experimental]
932 When enabled, tinc will try to detect peers that are on the same local network.
933 This will allow direct communication using LAN addresses, even if both peers are behind a NAT
934 and they only ConnectTo a third node outside the NAT,
935 which normally would prevent the peers from learning each other's LAN address.
937 Currently, local discovery is implemented by sending broadcast packets to the LAN during path MTU discovery.
938 This feature may not work in all possible situations.
941 @item Mode = <router|switch|hub> (router)
942 This option selects the way packets are routed to other daemons.
948 variables in the host configuration files will be used to form a routing table.
949 Only unicast packets of routable protocols (IPv4 and IPv6) are supported in this mode.
951 This is the default mode, and unless you really know you need another mode, don't change it.
955 In this mode the MAC addresses of the packets on the VPN will be used to
956 dynamically create a routing table just like an Ethernet switch does.
957 Unicast, multicast and broadcast packets of every protocol that runs over Ethernet are supported in this mode
958 at the cost of frequent broadcast ARP requests and routing table updates.
960 This mode is primarily useful if you want to bridge Ethernet segments.
964 This mode is almost the same as the switch mode, but instead
965 every packet will be broadcast to the other daemons
966 while no routing table is managed.
970 @item KeyExpire = <@var{seconds}> (3600)
971 This option controls the time the encryption keys used to encrypt the data
972 are valid. It is common practice to change keys at regular intervals to
973 make it even harder for crackers, even though it is thought to be nearly
974 impossible to crack a single key.
977 @item MACExpire = <@var{seconds}> (600)
978 This option controls the amount of time MAC addresses are kept before they are removed.
979 This only has effect when Mode is set to "switch".
982 @item Name = <@var{name}> [required]
983 This is a symbolic name for this connection.
984 The name should consist only of alfanumeric and underscore characters (a-z, A-Z, 0-9 and _).
987 @item PingInterval = <@var{seconds}> (60)
988 The number of seconds of inactivity that tinc will wait before sending a
989 probe to the other end.
992 @item PingTimeout = <@var{seconds}> (5)
993 The number of seconds to wait for a response to pings or to allow meta
994 connections to block. If the other end doesn't respond within this time,
995 the connection is terminated, and the others will be notified of this.
997 @cindex PriorityInheritance
998 @item PriorityInheritance = <yes|no> (no) [experimental]
999 When this option is enabled the value of the TOS field of tunneled IPv4 packets
1000 will be inherited by the UDP packets that are sent out.
1003 @item PrivateKey = <@var{key}> [obsolete]
1004 This is the RSA private key for tinc. However, for safety reasons it is
1005 advised to store private keys of any kind in separate files. This prevents
1006 accidental eavesdropping if you are editting the configuration file.
1008 @cindex PrivateKeyFile
1009 @item PrivateKeyFile = <@var{path}> (@file{@value{sysconfdir}/tinc/@var{netname}/rsa_key.priv})
1010 This is the full path name of the RSA private key file that was
1011 generated by @samp{tincd --generate-keys}. It must be a full path, not a
1014 Note that there must be exactly one of PrivateKey
1016 specified in the configuration file.
1018 @cindex ProcessPriority
1019 @item ProcessPriority = <low|normal|high>
1020 When this option is used the priority of the tincd process will be adjusted.
1021 Increasing the priority may help to reduce latency and packet loss on the VPN.
1023 @cindex ReplayWindow
1024 @item ReplayWindow = <bytes> (16)
1025 This is the size of the replay tracking window for each remote node, in bytes.
1026 The window is a bitfield which tracks 1 packet per bit, so for example
1027 the default setting of 16 will track up to 128 packets in the window. In high
1028 bandwidth scenarios, setting this to a higher value can reduce packet loss from
1029 the interaction of replay tracking with underlying real packet loss and/or
1030 reordering. Setting this to zero will disable replay tracking completely and
1031 pass all traffic, but leaves tinc vulnerable to replay-based attacks on your
1035 @cindex StrictSubnets
1036 @item StrictSubnets <yes|no> (no) [experimental]
1037 When this option is enabled tinc will only use Subnet statements which are
1038 present in the host config files in the local
1039 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
1041 @cindex TunnelServer
1042 @item TunnelServer = <yes|no> (no) [experimental]
1043 When this option is enabled tinc will no longer forward information between other tinc daemons,
1044 and will only allow connections with nodes for which host config files are present in the local
1045 @file{@value{sysconfdir}/tinc/@var{netname}/hosts/} directory.
1046 Setting this options also implicitly sets StrictSubnets.
1049 @item UDPRcvBuf = <bytes> (OS default)
1050 Sets the socket receive buffer size for the UDP socket, in bytes.
1051 If unset, the default buffer size will be used by the operating system.
1054 @item UDPSndBuf = <bytes> Pq OS default
1055 Sets the socket send buffer size for the UDP socket, in bytes.
1056 If unset, the default buffer size will be used by the operating system.
1061 @c ==================================================================
1062 @node Host configuration variables
1063 @subsection Host configuration variables
1067 @item Address = <@var{IP address}|@var{hostname}> [<port>] [recommended]
1068 This variable is only required if you want to connect to this host. It
1069 must resolve to the external IP address where the host can be reached,
1070 not the one that is internal to the VPN.
1071 If no port is specified, the default Port is used.
1074 @item Cipher = <@var{cipher}> (blowfish)
1075 The symmetric cipher algorithm used to encrypt UDP packets.
1076 Any cipher supported by OpenSSL is recognized.
1077 Furthermore, specifying "none" will turn off packet encryption.
1078 It is best to use only those ciphers which support CBC mode.
1081 @item ClampMSS = <yes|no> (yes)
1082 This option specifies whether tinc should clamp the maximum segment size (MSS)
1083 of TCP packets to the path MTU. This helps in situations where ICMP
1084 Fragmentation Needed or Packet too Big messages are dropped by firewalls.
1087 @item Compression = <@var{level}> (0)
1088 This option sets the level of compression used for UDP packets.
1089 Possible values are 0 (off), 1 (fast zlib) and any integer up to 9 (best zlib),
1090 10 (fast lzo) and 11 (best lzo).
1093 @item Digest = <@var{digest}> (sha1)
1094 The digest algorithm used to authenticate UDP packets.
1095 Any digest supported by OpenSSL is recognized.
1096 Furthermore, specifying "none" will turn off packet authentication.
1098 @cindex IndirectData
1099 @item IndirectData = <yes|no> (no)
1100 This option specifies whether other tinc daemons besides the one you
1101 specified with ConnectTo can make a direct connection to you. This is
1102 especially useful if you are behind a firewall and it is impossible to
1103 make a connection from the outside to your tinc daemon. Otherwise, it
1104 is best to leave this option out or set it to no.
1107 @item MACLength = <@var{bytes}> (4)
1108 The length of the message authentication code used to authenticate UDP packets.
1109 Can be anything from 0
1110 up to the length of the digest produced by the digest algorithm.
1113 @item PMTU = <@var{mtu}> (1514)
1114 This option controls the initial path MTU to this node.
1116 @cindex PMTUDiscovery
1117 @item PMTUDiscovery = <yes|no> (yes)
1118 When this option is enabled, tinc will try to discover the path MTU to this node.
1119 After the path MTU has been discovered, it will be enforced on the VPN.
1122 @item Port = <@var{port}> (655)
1123 This is the port this tinc daemon listens on.
1124 You can use decimal portnumbers or symbolic names (as listed in @file{/etc/services}).
1127 @item PublicKey = <@var{key}> [obsolete]
1128 This is the RSA public key for this host.
1130 @cindex PublicKeyFile
1131 @item PublicKeyFile = <@var{path}> [obsolete]
1132 This is the full path name of the RSA public key file that was generated
1133 by @samp{tincd --generate-keys}. It must be a full path, not a relative
1137 From version 1.0pre4 on tinc will store the public key directly into the
1138 host configuration file in PEM format, the above two options then are not
1139 necessary. Either the PEM format is used, or exactly
1140 @strong{one of the above two options} must be specified
1141 in each host configuration file, if you want to be able to establish a
1142 connection with that host.
1145 @item Subnet = <@var{address}[/@var{prefixlength}[#@var{weight}]]>
1146 The subnet which this tinc daemon will serve.
1147 Tinc tries to look up which other daemon it should send a packet to by searching the appropiate subnet.
1148 If the packet matches a subnet,
1149 it will be sent to the daemon who has this subnet in his host configuration file.
1150 Multiple subnet lines can be specified for each daemon.
1152 Subnets can either be single MAC, IPv4 or IPv6 addresses,
1153 in which case a subnet consisting of only that single address is assumed,
1154 or they can be a IPv4 or IPv6 network address with a prefixlength.
1155 Shorthand notations are not supported.
1156 For example, IPv4 subnets must be in a form like 192.168.1.0/24,
1157 where 192.168.1.0 is the network address and 24 is the number of bits set in the netmask.
1158 Note that subnets like 192.168.1.1/24 are invalid!
1159 Read a networking HOWTO/FAQ/guide if you don't understand this.
1160 IPv6 subnets are notated like fec0:0:0:1:0:0:0:0/64.
1161 MAC addresses are notated like 0:1a:2b:3c:4d:5e.
1163 @cindex CIDR notation
1164 Prefixlength is the number of bits set to 1 in the netmask part; for
1165 example: netmask 255.255.255.0 would become /24, 255.255.252.0 becomes
1166 /22. This conforms to standard CIDR notation as described in
1167 @uref{ftp://ftp.isi.edu/in-notes/rfc1519.txt, RFC1519}
1169 @cindex Subnet weight
1170 A Subnet can be given a weight to indicate its priority over identical Subnets
1171 owned by different nodes. The default weight is 10. Lower values indicate
1172 higher priority. Packets will be sent to the node with the highest priority,
1173 unless that node is not reachable, in which case the node with the next highest
1174 priority will be tried, and so on.
1177 @item TCPonly = <yes|no> (no) [deprecated]
1178 If this variable is set to yes, then the packets are tunnelled over a
1179 TCP connection instead of a UDP connection. This is especially useful
1180 for those who want to run a tinc daemon from behind a masquerading
1181 firewall, or if UDP packet routing is disabled somehow.
1182 Setting this options also implicitly sets IndirectData.
1184 Since version 1.0.10, tinc will automatically detect whether communication via
1185 UDP is possible or not.
1189 @c ==================================================================
1194 Apart from reading the server and host configuration files,
1195 tinc can also run scripts at certain moments.
1196 Under Windows (not Cygwin), the scripts should have the extension .bat.
1200 @item @value{sysconfdir}/tinc/@var{netname}/tinc-up
1201 This is the most important script.
1202 If it is present it will be executed right after the tinc daemon has been
1203 started and has connected to the virtual network device.
1204 It should be used to set up the corresponding network interface,
1205 but can also be used to start other things.
1206 Under Windows you can use the Network Connections control panel instead of creating this script.
1209 @item @value{sysconfdir}/tinc/@var{netname}/tinc-down
1210 This script is started right before the tinc daemon quits.
1212 @item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-up
1213 This script is started when the tinc daemon with name @var{host} becomes reachable.
1215 @item @value{sysconfdir}/tinc/@var{netname}/hosts/@var{host}-down
1216 This script is started when the tinc daemon with name @var{host} becomes unreachable.
1218 @item @value{sysconfdir}/tinc/@var{netname}/host-up
1219 This script is started when any host becomes reachable.
1221 @item @value{sysconfdir}/tinc/@var{netname}/host-down
1222 This script is started when any host becomes unreachable.
1224 @item @value{sysconfdir}/tinc/@var{netname}/subnet-up
1225 This script is started when a Subnet becomes reachable.
1226 The Subnet and the node it belongs to are passed in environment variables.
1228 @item @value{sysconfdir}/tinc/@var{netname}/subnet-down
1229 This script is started when a Subnet becomes unreachable.
1232 @cindex environment variables
1233 The scripts are started without command line arguments,
1234 but can make use of certain environment variables.
1235 Under UNIX like operating systems the names of environment variables must be preceded by a $ in scripts.
1236 Under Windows, in @file{.bat} files, they have to be put between % signs.
1241 If a netname was specified, this environment variable contains it.
1245 Contains the name of this tinc daemon.
1249 Contains the name of the virtual network device that tinc uses.
1253 Contains the name of the virtual network interface that tinc uses.
1254 This should be used for commands like ifconfig.
1258 When a host becomes (un)reachable, this is set to its name.
1259 If a subnet becomes (un)reachable, this is set to the owner of that subnet.
1261 @cindex REMOTEADDRESS
1263 When a host becomes (un)reachable, this is set to its real address.
1267 When a host becomes (un)reachable,
1268 this is set to the port number it uses for communication with other tinc daemons.
1272 When a subnet becomes (un)reachable, this is set to the subnet.
1276 When a subnet becomes (un)reachable, this is set to the subnet weight.
1281 @c ==================================================================
1282 @node How to configure
1283 @subsection How to configure
1285 @subsubheading Step 1. Creating the main configuration file
1287 The main configuration file will be called @file{@value{sysconfdir}/tinc/@var{netname}/tinc.conf}.
1288 Adapt the following example to create a basic configuration file:
1291 Name = @var{yourname}
1292 Device = @file{/dev/tap0}
1295 Then, if you know to which other tinc daemon(s) yours is going to connect,
1296 add `ConnectTo' values.
1298 @subsubheading Step 2. Creating your host configuration file
1300 If you added a line containing `Name = yourname' in the main configuarion file,
1301 you will need to create a host configuration file @file{@value{sysconfdir}/tinc/@var{netname}/hosts/yourname}.
1302 Adapt the following example to create a host configuration file:
1305 Address = your.real.hostname.org
1306 Subnet = 192.168.1.0/24
1309 You can also use an IP address instead of a hostname.
1310 The `Subnet' specifies the address range that is local for @emph{your part of the VPN only}.
1311 If you have multiple address ranges you can specify more than one `Subnet'.
1312 You might also need to add a `Port' if you want your tinc daemon to run on a different port number than the default (655).
1315 @c ==================================================================
1316 @node Generating keypairs
1317 @section Generating keypairs
1319 @cindex key generation
1320 Now that you have already created the main configuration file and your host configuration file,
1321 you can easily create a public/private keypair by entering the following command:
1324 tincd -n @var{netname} -K
1327 Tinc will generate a public and a private key and ask you where to put them.
1328 Just press enter to accept the defaults.
1331 @c ==================================================================
1332 @node Network interfaces
1333 @section Network interfaces
1335 Before tinc can start transmitting data over the tunnel, it must
1336 set up the virtual network interface.
1338 First, decide which IP addresses you want to have associated with these
1339 devices, and what network mask they must have.
1341 Tinc will open a virtual network device (@file{/dev/tun}, @file{/dev/tap0} or similar),
1342 which will also create a network interface called something like @samp{tun0}, @samp{tap0}.
1343 If you are using the Linux tun/tap driver, the network interface will by default have the same name as the @var{netname}.
1344 Under Windows you can change the name of the network interface from the Network Connections control panel.
1347 You can configure the network interface by putting ordinary ifconfig, route, and other commands
1348 to a script named @file{@value{sysconfdir}/tinc/@var{netname}/tinc-up}.
1349 When tinc starts, this script will be executed. When tinc exits, it will execute the script named
1350 @file{@value{sysconfdir}/tinc/@var{netname}/tinc-down}, but normally you don't need to create that script.
1352 An example @file{tinc-up} script:
1356 ifconfig $INTERFACE 192.168.1.1 netmask 255.255.0.0
1359 This script gives the interface an IP address and a netmask.
1360 The kernel will also automatically add a route to this interface, so normally you don't need
1361 to add route commands to the @file{tinc-up} script.
1362 The kernel will also bring the interface up after this command.
1364 The netmask is the mask of the @emph{entire} VPN network, not just your
1367 The exact syntax of the ifconfig and route commands differs from platform to platform.
1368 You can look up the commands for setting addresses and adding routes in @ref{Platform specific information},
1369 but it is best to consult the manpages of those utilities on your platform.
1372 @c ==================================================================
1373 @node Example configuration
1374 @section Example configuration
1378 Imagine the following situation. Branch A of our example `company' wants to connect
1379 three branch offices in B, C and D using the Internet. All four offices
1380 have a 24/7 connection to the Internet.
1382 A is going to serve as the center of the network. B and C will connect
1383 to A, and D will connect to C. Each office will be assigned their own IP
1387 A: net 10.1.0.0 mask 255.255.0.0 gateway 10.1.54.1 internet IP 1.2.3.4
1388 B: net 10.2.0.0 mask 255.255.0.0 gateway 10.2.1.12 internet IP 2.3.4.5
1389 C: net 10.3.0.0 mask 255.255.0.0 gateway 10.3.69.254 internet IP 3.4.5.6
1390 D: net 10.4.0.0 mask 255.255.0.0 gateway 10.4.3.32 internet IP 4.5.6.7
1393 Here, ``gateway'' is the VPN IP address of the machine that is running the
1394 tincd, and ``internet IP'' is the IP address of the firewall, which does not
1395 need to run tincd, but it must do a port forwarding of TCP and UDP on port
1396 655 (unless otherwise configured).
1398 In this example, it is assumed that eth0 is the interface that points to
1399 the inner (physical) LAN of the office, although this could also be the
1400 same as the interface that leads to the Internet. The configuration of
1401 the real interface is also shown as a comment, to give you an idea of
1402 how these example host is set up. All branches use the netname `company'
1403 for this particular VPN.
1405 @subsubheading For Branch A
1407 @emph{BranchA} would be configured like this:
1409 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1412 # Real interface of internal network:
1413 # ifconfig eth0 10.1.54.1 netmask 255.255.0.0
1415 ifconfig $INTERFACE 10.1.54.1 netmask 255.0.0.0
1418 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1425 On all hosts, @file{@value{sysconfdir}/tinc/company/hosts/BranchA} contains:
1428 Subnet = 10.1.0.0/16
1431 -----BEGIN RSA PUBLIC KEY-----
1433 -----END RSA PUBLIC KEY-----
1436 Note that the IP addresses of eth0 and tap0 are the same.
1437 This is quite possible, if you make sure that the netmasks of the interfaces are different.
1438 It is in fact recommended to give both real internal network interfaces and tap interfaces the same IP address,
1439 since that will make things a lot easier to remember and set up.
1442 @subsubheading For Branch B
1444 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1447 # Real interface of internal network:
1448 # ifconfig eth0 10.2.43.8 netmask 255.255.0.0
1450 ifconfig $INTERFACE 10.2.1.12 netmask 255.0.0.0
1453 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1460 Note here that the internal address (on eth0) doesn't have to be the
1461 same as on the tap0 device. Also, ConnectTo is given so that this node will
1462 always try to connect to BranchA.
1464 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchB}:
1467 Subnet = 10.2.0.0/16
1470 -----BEGIN RSA PUBLIC KEY-----
1472 -----END RSA PUBLIC KEY-----
1476 @subsubheading For Branch C
1478 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1481 # Real interface of internal network:
1482 # ifconfig eth0 10.3.69.254 netmask 255.255.0.0
1484 ifconfig $INTERFACE 10.3.69.254 netmask 255.0.0.0
1487 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1495 C already has another daemon that runs on port 655, so they have to
1496 reserve another port for tinc. It knows the portnumber it has to listen on
1497 from it's own host configuration file.
1499 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchC}:
1503 Subnet = 10.3.0.0/16
1506 -----BEGIN RSA PUBLIC KEY-----
1508 -----END RSA PUBLIC KEY-----
1512 @subsubheading For Branch D
1514 In @file{@value{sysconfdir}/tinc/company/tinc-up}:
1517 # Real interface of internal network:
1518 # ifconfig eth0 10.4.3.32 netmask 255.255.0.0
1520 ifconfig $INTERFACE 10.4.3.32 netmask 255.0.0.0
1523 and in @file{@value{sysconfdir}/tinc/company/tinc.conf}:
1528 Device = /dev/net/tun
1531 D will be connecting to C, which has a tincd running for this network on
1532 port 2000. It knows the port number from the host configuration file.
1533 Also note that since D uses the tun/tap driver, the network interface
1534 will not be called `tun' or `tap0' or something like that, but will
1535 have the same name as netname.
1537 On all hosts, in @file{@value{sysconfdir}/tinc/company/hosts/BranchD}:
1540 Subnet = 10.4.0.0/16
1543 -----BEGIN RSA PUBLIC KEY-----
1545 -----END RSA PUBLIC KEY-----
1548 @subsubheading Key files
1550 A, B, C and D all have generated a public/private keypair with the following command:
1556 The private key is stored in @file{@value{sysconfdir}/tinc/company/rsa_key.priv},
1557 the public key is put into the host configuration file in the @file{@value{sysconfdir}/tinc/company/hosts/} directory.
1558 During key generation, tinc automatically guesses the right filenames based on the -n option and
1559 the Name directive in the @file{tinc.conf} file (if it is available).
1561 @subsubheading Starting
1563 After each branch has finished configuration and they have distributed
1564 the host configuration files amongst them, they can start their tinc daemons.
1565 They don't necessarily have to wait for the other branches to have started
1566 their daemons, tinc will try connecting until they are available.
1569 @c ==================================================================
1571 @chapter Running tinc
1573 If everything else is done, you can start tinc by typing the following command:
1576 tincd -n @var{netname}
1580 Tinc will detach from the terminal and continue to run in the background like a good daemon.
1581 If there are any problems however you can try to increase the debug level
1582 and look in the syslog to find out what the problems are.
1588 * Solving problems::
1590 * Sending bug reports::
1594 @c ==================================================================
1595 @node Runtime options
1596 @section Runtime options
1598 Besides the settings in the configuration file, tinc also accepts some
1599 command line options.
1601 @cindex command line
1602 @cindex runtime options
1606 @item -c, --config=@var{path}
1607 Read configuration options from the directory @var{path}. The default is
1608 @file{@value{sysconfdir}/tinc/@var{netname}/}.
1610 @item -D, --no-detach
1611 Don't fork and detach.
1612 This will also disable the automatic restart mechanism for fatal errors.
1615 @item -d, --debug=@var{level}
1616 Set debug level to @var{level}. The higher the debug level, the more gets
1617 logged. Everything goes via syslog.
1619 @item -k, --kill[=@var{signal}]
1620 Attempt to kill a running tincd (optionally with the specified @var{signal} instead of SIGTERM) and exit.
1621 Use it in conjunction with the -n option to make sure you kill the right tinc daemon.
1622 Under native Windows the optional argument is ignored,
1623 the service will always be stopped and removed.
1625 @item -n, --net=@var{netname}
1626 Use configuration for net @var{netname}.
1627 This will let tinc read all configuration files from
1628 @file{@value{sysconfdir}/tinc/@var{netname}/}.
1629 Specifying . for @var{netname} is the same as not specifying any @var{netname}.
1630 @xref{Multiple networks}.
1632 @item -K, --generate-keys[=@var{bits}]
1633 Generate public/private keypair of @var{bits} length. If @var{bits} is not specified,
1634 2048 is the default. tinc will ask where you want to store the files,
1635 but will default to the configuration directory (you can use the -c or -n option
1636 in combination with -K). After that, tinc will quit.
1638 @item -o, --option=[@var{HOST}.]@var{KEY}=@var{VALUE}
1639 Without specifying a @var{HOST}, this will set server configuration variable @var{KEY} to @var{VALUE}.
1640 If specified as @var{HOST}.@var{KEY}=@var{VALUE},
1641 this will set the host configuration variable @var{KEY} of the host named @var{HOST} to @var{VALUE}.
1642 This option can be used more than once to specify multiple configuration variables.
1645 Lock tinc into main memory.
1646 This will prevent sensitive data like shared private keys to be written to the system swap files/partitions.
1648 @item --logfile[=@var{file}]
1649 Write log entries to a file instead of to the system logging facility.
1650 If @var{file} is omitted, the default is @file{@value{localstatedir}/log/tinc.@var{netname}.log}.
1652 @item --pidfile=@var{file}
1653 Write PID to @var{file} instead of @file{@value{localstatedir}/run/tinc.@var{netname}.pid}.
1655 @item --bypass-security
1656 Disables encryption and authentication.
1657 Only useful for debugging.
1660 Change process root directory to the directory where the config file is
1661 located (@file{@value{sysconfdir}/tinc/@var{netname}/} as determined by
1662 -n/--net option or as given by -c/--config option), for added security.
1663 The chroot is performed after all the initialization is done, after
1664 writing pid files and opening network sockets.
1666 Note that this option alone does not do any good without -U/--user, below.
1668 Note also that tinc can't run scripts anymore (such as tinc-down or host-up),
1669 unless it's setup to be runnable inside chroot environment.
1671 @item -U, --user=@var{user}
1672 Switch to the given @var{user} after initialization, at the same time as
1673 chroot is performed (see --chroot above). With this option tinc drops
1674 privileges, for added security.
1677 Display a short reminder of these runtime options and terminate.
1680 Output version information and exit.
1684 @c ==================================================================
1689 You can also send the following signals to a running tincd process:
1695 Forces tinc to try to connect to all uplinks immediately.
1696 Usually tinc attempts to do this itself,
1697 but increases the time it waits between the attempts each time it failed,
1698 and if tinc didn't succeed to connect to an uplink the first time after it started,
1699 it defaults to the maximum time of 15 minutes.
1702 Partially rereads configuration files.
1703 Connections to hosts whose host config file are removed are closed.
1704 New outgoing connections specified in @file{tinc.conf} will be made.
1705 If the --logfile option is used, this will also close and reopen the log file,
1706 useful when log rotation is used.
1709 Temporarily increases debug level to 5.
1710 Send this signal again to revert to the original level.
1713 Dumps the connection list to syslog.
1716 Dumps virtual network device statistics, all known nodes, edges and subnets to syslog.
1719 Purges all information remembered about unreachable nodes.
1723 @c ==================================================================
1725 @section Debug levels
1727 @cindex debug levels
1728 The tinc daemon can send a lot of messages to the syslog.
1729 The higher the debug level, the more messages it will log.
1730 Each level inherits all messages of the previous level:
1736 This will log a message indicating tinc has started along with a version number.
1737 It will also log any serious error.
1740 This will log all connections that are made with other tinc daemons.
1743 This will log status and error messages from scripts and other tinc daemons.
1746 This will log all requests that are exchanged with other tinc daemons. These include
1747 authentication, key exchange and connection list updates.
1750 This will log a copy of everything received on the meta socket.
1753 This will log all network traffic over the virtual private network.
1757 @c ==================================================================
1758 @node Solving problems
1759 @section Solving problems
1761 If tinc starts without problems, but if the VPN doesn't work, you will have to find the cause of the problem.
1762 The first thing to do is to start tinc with a high debug level in the foreground,
1763 so you can directly see everything tinc logs:
1766 tincd -n @var{netname} -d5 -D
1769 If tinc does not log any error messages, then you might want to check the following things:
1772 @item @file{tinc-up} script
1773 Does this script contain the right commands?
1774 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.
1777 Does the Subnet (or Subnets) in the host configuration file of this host match the portion of the VPN that belongs to this host?
1779 @item Firewalls and NATs
1780 Do you have a firewall or a NAT device (a masquerading firewall or perhaps an ADSL router that performs masquerading)?
1781 If so, check that it allows TCP and UDP traffic on port 655.
1782 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.
1783 You can add @samp{TCPOnly = yes} to your host config file to force tinc to only use a single TCP connection,
1784 this works through most firewalls and NATs. Since version 1.0.10, tinc will automatically fall back to TCP if direct communication via UDP is not possible.
1789 @c ==================================================================
1790 @node Error messages
1791 @section Error messages
1793 What follows is a list of the most common error messages you might find in the logs.
1794 Some of them will only be visible if the debug level is high enough.
1797 @item Could not open /dev/tap0: No such device
1800 @item You forgot to `modprobe netlink_dev' or `modprobe ethertap'.
1801 @item You forgot to compile `Netlink device emulation' in the kernel.
1804 @item Can't write to /dev/net/tun: No such device
1807 @item You forgot to `modprobe tun'.
1808 @item You forgot to compile `Universal TUN/TAP driver' in the kernel.
1809 @item The tun device is located somewhere else in @file{/dev/}.
1812 @item Network address and prefix length do not match!
1815 @item The Subnet field must contain a @emph{network} address, trailing bits should be 0.
1816 @item If you only want to use one IP address, set the netmask to /32.
1819 @item Error reading RSA key file `rsa_key.priv': No such file or directory
1822 @item You forgot to create a public/private keypair.
1823 @item Specify the complete pathname to the private key file with the @samp{PrivateKeyFile} option.
1826 @item Warning: insecure file permissions for RSA private key file `rsa_key.priv'!
1829 @item The private key file is readable by users other than root.
1830 Use chmod to correct the file permissions.
1833 @item Creating metasocket failed: Address family not supported
1836 @item By default tinc tries to create both IPv4 and IPv6 sockets.
1837 On some platforms this might not be implemented.
1838 If the logs show @samp{Ready} later on, then at least one metasocket was created,
1839 and you can ignore this message.
1840 You can add @samp{AddressFamily = ipv4} to @file{tinc.conf} to prevent this from happening.
1843 @item Cannot route packet: unknown IPv4 destination 1.2.3.4
1846 @item You try to send traffic to a host on the VPN for which no Subnet is known.
1847 @item If it is a broadcast address (ending in .255), it probably is a samba server or a Windows host sending broadcast packets.
1851 @item Cannot route packet: ARP request for unknown address 1.2.3.4
1854 @item You try to send traffic to a host on the VPN for which no Subnet is known.
1857 @item Packet with destination 1.2.3.4 is looping back to us!
1860 @item Something is not configured right. Packets are being sent out to the
1861 virtual network device, but according to the Subnet directives in your host configuration
1862 file, those packets should go to your own host. Most common mistake is that
1863 you have a Subnet line in your host configuration file with a prefix length which is
1864 just as large as the prefix of the virtual network interface. The latter should in almost all
1865 cases be larger. Rethink your configuration.
1866 Note that you will only see this message if you specified a debug
1867 level of 5 or higher!
1868 @item Chances are that a @samp{Subnet = ...} line in the host configuration file of this tinc daemon is wrong.
1869 Change it to a subnet that is accepted locally by another interface,
1870 or if that is not the case, try changing the prefix length into /32.
1873 @item Node foo (1.2.3.4) is not reachable
1876 @item Node foo does not have a connection anymore, its tinc daemon is not running or its connection to the Internet is broken.
1879 @item Received UDP packet from unknown source 1.2.3.4 (port 12345)
1882 @item If you see this only sporadically, it is harmless and caused by a node sending packets using an old key.
1885 @item Got bad/bogus/unauthorized REQUEST from foo (1.2.3.4 port 12345)
1888 @item Node foo does not have the right public/private keypair.
1889 Generate new keypairs and distribute them again.
1890 @item An attacker tries to gain access to your VPN.
1891 @item A network error caused corruption of metadata sent from foo.
1896 @c ==================================================================
1897 @node Sending bug reports
1898 @section Sending bug reports
1900 If you really can't find the cause of a problem, or if you suspect tinc is not working right,
1901 you can send us a bugreport, see @ref{Contact information}.
1902 Be sure to include the following information in your bugreport:
1905 @item A clear description of what you are trying to achieve and what the problem is.
1906 @item What platform (operating system, version, hardware architecture) and which version of tinc you use.
1907 @item If compiling tinc fails, a copy of @file{config.log} and the error messages you get.
1908 @item Otherwise, a copy of @file{tinc.conf}, @file{tinc-up} and all files in the @file{hosts/} directory.
1909 @item The output of the commands @samp{ifconfig -a} and @samp{route -n} (or @samp{netstat -rn} if that doesn't work).
1910 @item The output of any command that fails to work as it should (like ping or traceroute).
1913 @c ==================================================================
1914 @node Technical information
1915 @chapter Technical information
1920 * The meta-protocol::
1925 @c ==================================================================
1926 @node The connection
1927 @section The connection
1930 Tinc is a daemon that takes VPN data and transmit that to another host
1931 computer over the existing Internet infrastructure.
1935 * The meta-connection::
1939 @c ==================================================================
1940 @node The UDP tunnel
1941 @subsection The UDP tunnel
1943 @cindex virtual network device
1945 The data itself is read from a character device file, the so-called
1946 @emph{virtual network device}. This device is associated with a network
1947 interface. Any data sent to this interface can be read from the device,
1948 and any data written to the device gets sent from the interface.
1949 There are two possible types of virtual network devices:
1950 `tun' style, which are point-to-point devices which can only handle IPv4 and/or IPv6 packets,
1951 and `tap' style, which are Ethernet devices and handle complete Ethernet frames.
1953 So when tinc reads an Ethernet frame from the device, it determines its
1954 type. When tinc is in it's default routing mode, it can handle IPv4 and IPv6
1955 packets. Depending on the Subnet lines, it will send the packets off to their destination IP address.
1956 In the `switch' and `hub' mode, tinc will use broadcasts and MAC address discovery
1957 to deduce the destination of the packets.
1958 Since the latter modes only depend on the link layer information,
1959 any protocol that runs over Ethernet is supported (for instance IPX and Appletalk).
1960 However, only `tap' style devices provide this information.
1962 After the destination has been determined,
1963 the packet will be compressed (optionally),
1964 a sequence number will be added to the packet,
1965 the packet will then be encrypted
1966 and a message authentication code will be appended.
1968 @cindex encapsulating
1970 When that is done, time has come to actually transport the
1971 packet to the destination computer. We do this by sending the packet
1972 over an UDP connection to the destination host. This is called
1973 @emph{encapsulating}, the VPN packet (though now encrypted) is
1974 encapsulated in another IP datagram.
1976 When the destination receives this packet, the same thing happens, only
1977 in reverse. So it checks the message authentication code, decrypts the contents of the UDP datagram,
1978 checks the sequence number
1979 and writes the decrypted information to its own virtual network device.
1981 If the virtual network device is a `tun' device (a point-to-point tunnel),
1982 there is no problem for the kernel to accept a packet.
1983 However, if it is a `tap' device (this is the only available type on FreeBSD),
1984 the destination MAC address must match that of the virtual network interface.
1985 If tinc is in it's default routing mode, ARP does not work, so the correct destination MAC
1986 can not be known by the sending host.
1987 Tinc solves this by letting the receiving end detect the MAC address of its own virtual network interface
1988 and overwriting the destination MAC address of the received packet.
1990 In switch or hub modes ARP does work so the sender already knows the correct destination MAC address.
1991 In those modes every interface should have a unique MAC address, so make sure they are not the same.
1992 Because switch and hub modes rely on MAC addresses to function correctly,
1993 these modes cannot be used on the following operating systems which don't have a `tap' style virtual network device:
1994 OpenBSD, NetBSD, Darwin and Solaris.
1997 @c ==================================================================
1998 @node The meta-connection
1999 @subsection The meta-connection
2001 Having only a UDP connection available is not enough. Though suitable
2002 for transmitting data, we want to be able to reliably send other
2003 information, such as routing and session key information to somebody.
2006 TCP is a better alternative, because it already contains protection
2007 against information being lost, unlike UDP.
2009 So we establish two connections. One for the encrypted VPN data, and one
2010 for other information, the meta-data. Hence, we call the second
2011 connection the meta-connection. We can now be sure that the
2012 meta-information doesn't get lost on the way to another computer.
2014 @cindex data-protocol
2015 @cindex meta-protocol
2016 Like with any communication, we must have a protocol, so that everybody
2017 knows what everything stands for, and how she should react. Because we
2018 have two connections, we also have two protocols. The protocol used for
2019 the UDP data is the ``data-protocol,'' the other one is the
2022 The reason we don't use TCP for both protocols is that UDP is much
2023 better for encapsulation, even while it is less reliable. The real
2024 problem is that when TCP would be used to encapsulate a TCP stream
2025 that's on the private network, for every packet sent there would be
2026 three ACKs sent instead of just one. Furthermore, if there would be
2027 a timeout, both TCP streams would sense the timeout, and both would
2028 start re-sending packets.
2031 @c ==================================================================
2032 @node The meta-protocol
2033 @section The meta-protocol
2035 The meta protocol is used to tie all tinc daemons together, and
2036 exchange information about which tinc daemon serves which virtual
2039 The meta protocol consists of requests that can be sent to the other
2040 side. Each request has a unique number and several parameters. All
2041 requests are represented in the standard ASCII character set. It is
2042 possible to use tools such as telnet or netcat to connect to a tinc
2043 daemon started with the --bypass-security option
2044 and to read and write requests by hand, provided that one
2045 understands the numeric codes sent.
2047 The authentication scheme is described in @ref{Authentication protocol}. After a
2048 successful authentication, the server and the client will exchange all the
2049 information about other tinc daemons and subnets they know of, so that both
2050 sides (and all the other tinc daemons behind them) have their information
2057 ------------------------------------------------------------------
2058 ADD_EDGE node1 node2 21.32.43.54 655 222 0
2059 | | | | | +-> options
2060 | | | | +----> weight
2061 | | | +--------> UDP port of node2
2062 | | +----------------> real address of node2
2063 | +-------------------------> name of destination node
2064 +-------------------------------> name of source node
2066 ADD_SUBNET node 192.168.1.0/24
2067 | | +--> prefixlength
2068 | +--------> network address
2069 +------------------> owner of this subnet
2070 ------------------------------------------------------------------
2073 The ADD_EDGE messages are to inform other tinc daemons that a connection between
2074 two nodes exist. The address of the destination node is available so that
2075 VPN packets can be sent directly to that node.
2077 The ADD_SUBNET messages inform other tinc daemons that certain subnets belong
2078 to certain nodes. tinc will use it to determine to which node a VPN packet has
2085 ------------------------------------------------------------------
2086 DEL_EDGE node1 node2
2087 | +----> name of destination node
2088 +----------> name of source node
2090 DEL_SUBNET node 192.168.1.0/24
2091 | | +--> prefixlength
2092 | +--------> network address
2093 +------------------> owner of this subnet
2094 ------------------------------------------------------------------
2097 In case a connection between two daemons is closed or broken, DEL_EDGE messages
2098 are sent to inform the other daemons of that fact. Each daemon will calculate a
2099 new route to the the daemons, or mark them unreachable if there isn't any.
2106 ------------------------------------------------------------------
2107 REQ_KEY origin destination
2108 | +--> name of the tinc daemon it wants the key from
2109 +----------> name of the daemon that wants the key
2111 ANS_KEY origin destination 4ae0b0a82d6e0078 91 64 4
2112 | | \______________/ | | +--> MAC length
2113 | | | | +-----> digest algorithm
2114 | | | +--------> cipher algorithm
2115 | | +--> 128 bits key
2116 | +--> name of the daemon that wants the key
2117 +----------> name of the daemon that uses this key
2120 +--> daemon that has changed it's packet key
2121 ------------------------------------------------------------------
2124 The keys used to encrypt VPN packets are not sent out directly. This is
2125 because it would generate a lot of traffic on VPNs with many daemons, and
2126 chances are that not every tinc daemon will ever send a packet to every
2127 other daemon. Instead, if a daemon needs a key it sends a request for it
2128 via the meta connection of the nearest hop in the direction of the
2135 ------------------------------------------------------------------
2138 ------------------------------------------------------------------
2141 There is also a mechanism to check if hosts are still alive. Since network
2142 failures or a crash can cause a daemon to be killed without properly
2143 shutting down the TCP connection, this is necessary to keep an up to date
2144 connection list. PINGs are sent at regular intervals, except when there
2145 is also some other traffic. A little bit of salt (random data) is added
2146 with each PING and PONG message, to make sure that long sequences of PING/PONG
2147 messages without any other traffic won't result in known plaintext.
2149 This basically covers what is sent over the meta connection by tinc.
2152 @c ==================================================================
2158 Tinc got its name from ``TINC,'' short for @emph{There Is No Cabal}; the
2159 alleged Cabal was/is an organisation that was said to keep an eye on the
2160 entire Internet. As this is exactly what you @emph{don't} want, we named
2161 the tinc project after TINC.
2164 But in order to be ``immune'' to eavesdropping, you'll have to encrypt
2165 your data. Because tinc is a @emph{Secure} VPN (SVPN) daemon, it does
2166 exactly that: encrypt.
2167 Tinc by default uses blowfish encryption with 128 bit keys in CBC mode, 32 bit
2168 sequence numbers and 4 byte long message authentication codes to make sure
2169 eavesdroppers cannot get and cannot change any information at all from the
2170 packets they can intercept. The encryption algorithm and message authentication
2171 algorithm can be changed in the configuration. The length of the message
2172 authentication codes is also adjustable. The length of the key for the
2173 encryption algorithm is always the default length used by OpenSSL.
2176 * Authentication protocol::
2177 * Encryption of network packets::
2182 @c ==================================================================
2183 @node Authentication protocol
2184 @subsection Authentication protocol
2186 @cindex authentication
2187 A new scheme for authentication in tinc has been devised, which offers some
2188 improvements over the protocol used in 1.0pre2 and 1.0pre3. Explanation is
2198 --------------------------------------------------------------------------
2199 client <attempts connection>
2201 server <accepts connection>
2205 +-------> name of tinc daemon
2209 +-------> name of tinc daemon
2211 client META_KEY 5f0823a93e35b69e...7086ec7866ce582b
2212 \_________________________________/
2213 +-> RSAKEYLEN bits totally random string S1,
2214 encrypted with server's public RSA key
2216 server META_KEY 6ab9c1640388f8f0...45d1a07f8a672630
2217 \_________________________________/
2218 +-> RSAKEYLEN bits totally random string S2,
2219 encrypted with client's public RSA key
2222 - the client will symmetrically encrypt outgoing traffic using S1
2223 - the server will symmetrically encrypt outgoing traffic using S2
2225 client CHALLENGE da02add1817c1920989ba6ae2a49cecbda0
2226 \_________________________________/
2227 +-> CHALLEN bits totally random string H1
2229 server CHALLENGE 57fb4b2ccd70d6bb35a64c142f47e61d57f
2230 \_________________________________/
2231 +-> CHALLEN bits totally random string H2
2233 client CHAL_REPLY 816a86
2234 +-> 160 bits SHA1 of H2
2236 server CHAL_REPLY 928ffe
2237 +-> 160 bits SHA1 of H1
2239 After the correct challenge replies are received, both ends have proved
2240 their identity. Further information is exchanged.
2242 client ACK 655 123 0
2244 | +----> estimated weight
2245 +--------> listening port of client
2247 server ACK 655 321 0
2249 | +----> estimated weight
2250 +--------> listening port of server
2251 --------------------------------------------------------------------------
2254 This new scheme has several improvements, both in efficiency and security.
2256 First of all, the server sends exactly the same kind of messages over the wire
2257 as the client. The previous versions of tinc first authenticated the client,
2258 and then the server. This scheme even allows both sides to send their messages
2259 simultaneously, there is no need to wait for the other to send something first.
2260 This means that any calculations that need to be done upon sending or receiving
2261 a message can also be done in parallel. This is especially important when doing
2262 RSA encryption/decryption. Given that these calculations are the main part of
2263 the CPU time spent for the authentication, speed is improved by a factor 2.
2265 Second, only one RSA encrypted message is sent instead of two. This reduces the
2266 amount of information attackers can see (and thus use for a cryptographic
2267 attack). It also improves speed by a factor two, making the total speedup a
2270 Third, and most important:
2271 The symmetric cipher keys are exchanged first, the challenge is done
2272 afterwards. In the previous authentication scheme, because a man-in-the-middle
2273 could pass the challenge/chal_reply phase (by just copying the messages between
2274 the two real tinc daemons), but no information was exchanged that was really
2275 needed to read the rest of the messages, the challenge/chal_reply phase was of
2276 no real use. The man-in-the-middle was only stopped by the fact that only after
2277 the ACK messages were encrypted with the symmetric cipher. Potentially, it
2278 could even send it's own symmetric key to the server (if it knew the server's
2279 public key) and read some of the metadata the server would send it (it was
2280 impossible for the mitm to read actual network packets though). The new scheme
2281 however prevents this.
2283 This new scheme makes sure that first of all, symmetric keys are exchanged. The
2284 rest of the messages are then encrypted with the symmetric cipher. Then, each
2285 side can only read received messages if they have their private key. The
2286 challenge is there to let the other side know that the private key is really
2287 known, because a challenge reply can only be sent back if the challenge is
2288 decrypted correctly, and that can only be done with knowledge of the private
2291 Fourth: the first thing that is sent via the symmetric cipher encrypted
2292 connection is a totally random string, so that there is no known plaintext (for
2293 an attacker) in the beginning of the encrypted stream.
2296 @c ==================================================================
2297 @node Encryption of network packets
2298 @subsection Encryption of network packets
2301 A data packet can only be sent if the encryption key is known to both
2302 parties, and the connection is activated. If the encryption key is not
2303 known, a request is sent to the destination using the meta connection
2304 to retrieve it. The packet is stored in a queue while waiting for the
2308 The UDP packet containing the network packet from the VPN has the following layout:
2311 ... | IP header | UDP header | seqno | VPN packet | MAC | UDP trailer
2312 \___________________/\_____/
2314 V +---> digest algorithm
2315 Encrypted with symmetric cipher
2318 So, the entire VPN packet is encrypted using a symmetric cipher, including a 32 bits
2319 sequence number that is added in front of the actual VPN packet, to act as a unique
2320 IV for each packet and to prevent replay attacks. A message authentication code
2321 is added to the UDP packet to prevent alteration of packets. By default the
2322 first 4 bytes of the digest are used for this, but this can be changed using
2323 the MACLength configuration variable.
2325 @c ==================================================================
2326 @node Security issues
2327 @subsection Security issues
2329 In August 2000, we discovered the existence of a security hole in all versions
2330 of tinc up to and including 1.0pre2. This had to do with the way we exchanged
2331 keys. Since then, we have been working on a new authentication scheme to make
2332 tinc as secure as possible. The current version uses the OpenSSL library and
2333 uses strong authentication with RSA keys.
2335 On the 29th of December 2001, Jerome Etienne posted a security analysis of tinc
2336 1.0pre4. Due to a lack of sequence numbers and a message authentication code
2337 for each packet, an attacker could possibly disrupt certain network services or
2338 launch a denial of service attack by replaying intercepted packets. The current
2339 version adds sequence numbers and message authentication codes to prevent such
2342 On the 15th of September 2003, Peter Gutmann posted a security analysis of tinc
2343 1.0.1. He argues that the 32 bit sequence number used by tinc is not a good IV,
2344 that tinc's default length of 4 bytes for the MAC is too short, and he doesn't
2345 like tinc's use of RSA during authentication. We do not know of a security hole
2346 in this version of tinc, but tinc's security is not as strong as TLS or IPsec.
2347 We will address these issues in tinc 2.0.
2349 Cryptography is a hard thing to get right. We cannot make any
2350 guarantees. Time, review and feedback are the only things that can
2351 prove the security of any cryptographic product. If you wish to review
2352 tinc or give us feedback, you are stronly encouraged to do so.
2355 @c ==================================================================
2356 @node Platform specific information
2357 @chapter Platform specific information
2360 * Interface configuration::
2364 @c ==================================================================
2365 @node Interface configuration
2366 @section Interface configuration
2368 When configuring an interface, one normally assigns it an address and a
2369 netmask. The address uniquely identifies the host on the network attached to
2370 the interface. The netmask, combined with the address, forms a subnet. It is
2371 used to add a route to the routing table instructing the kernel to send all
2372 packets which fall into that subnet to that interface. Because all packets for
2373 the entire VPN should go to the virtual network interface used by tinc, the
2374 netmask should be such that it encompasses the entire VPN.
2378 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2380 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2381 @item Linux iproute2
2382 @tab @code{ip addr add} @var{address}@code{/}@var{prefixlength} @code{dev} @var{interface}
2384 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2386 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2388 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2390 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2391 @item Darwin (MacOS/X)
2392 @tab @code{ifconfig} @var{interface} @var{address} @code{netmask} @var{netmask}
2394 @tab @code{netsh interface ip set address} @var{interface} @code{static} @var{address} @var{netmask}
2400 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2402 @tab @code{ifconfig} @var{interface} @code{add} @var{address}@code{/}@var{prefixlength}
2404 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2406 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2408 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2410 @tab @code{ifconfig} @var{interface} @code{inet6 plumb up}
2412 @tab @code{ifconfig} @var{interface} @code{inet6 addif} @var{address} @var{address}
2413 @item Darwin (MacOS/X)
2414 @tab @code{ifconfig} @var{interface} @code{inet6} @var{address} @code{prefixlen} @var{prefixlength}
2416 @tab @code{netsh interface ipv6 add address} @var{interface} @code{static} @var{address}/@var{prefixlength}
2420 @c ==================================================================
2424 In some cases it might be necessary to add more routes to the virtual network
2425 interface. There are two ways to indicate which interface a packet should go
2426 to, one is to use the name of the interface itself, another way is to specify
2427 the (local) address that is assigned to that interface (@var{local_address}). The
2428 former way is unambiguous and therefore preferable, but not all platforms
2431 Adding routes to IPv4 subnets:
2433 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2435 @tab @code{route add -net} @var{network_address} @code{netmask} @var{netmask} @var{interface}
2436 @item Linux iproute2
2437 @tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
2439 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2441 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2443 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2445 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
2446 @item Darwin (MacOS/X)
2447 @tab @code{route add} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2449 @tab @code{netsh routing ip add persistentroute} @var{network_address} @var{netmask} @var{interface} @var{local_address}
2452 Adding routes to IPv6 subnets:
2454 @multitable {Darwin (MacOS/X)} {ifconfig route add -bla network address netmask netmask prefixlength interface}
2456 @tab @code{route add -A inet6} @var{network_address}@code{/}@var{prefixlength} @var{interface}
2457 @item Linux iproute2
2458 @tab @code{ip route add} @var{network_address}@code{/}@var{prefixlength} @code{dev} @var{interface}
2460 @tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address}
2462 @tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
2464 @tab @code{route add -inet6} @var{network_address} @var{local_address} @code{-prefixlen} @var{prefixlength}
2466 @tab @code{route add -inet6} @var{network_address}@code{/}@var{prefixlength} @var{local_address} @code{-interface}
2467 @item Darwin (MacOS/X)
2470 @tab @code{netsh interface ipv6 add route} @var{network address}/@var{prefixlength} @var{interface}
2474 @c ==================================================================
2480 * Contact information::
2485 @c ==================================================================
2486 @node Contact information
2487 @section Contact information
2490 Tinc's website is at @url{http://www.tinc-vpn.org/},
2491 this server is located in the Netherlands.
2494 We have an IRC channel on the FreeNode and OFTC IRC networks. Connect to
2495 @uref{http://www.freenode.net/, irc.freenode.net}
2497 @uref{http://www.oftc.net/, irc.oftc.net}
2498 and join channel #tinc.
2501 @c ==================================================================
2506 @item Ivo Timmermans (zarq)
2507 @item Guus Sliepen (guus) (@email{guus@@tinc-vpn.org})
2510 We have received a lot of valuable input from users. With their help,
2511 tinc has become the flexible and robust tool that it is today. We have
2512 composed a list of contributions, in the file called @file{THANKS} in
2513 the source distribution.
2516 @c ==================================================================
2518 @unnumbered Concept Index
2520 @c ==================================================================
2524 @c ==================================================================