3 .\" Manual page created by:
5 .\" Guus Sliepen <guus@tinc-vpn.org>
9 .Nd tinc daemon configuration
13 .Pa @sysconfdir@/tinc/
14 directory contain runtime and security information for the tinc daemon.
17 It is perfectly ok for you to run more than one tinc daemon.
18 However, in its default form,
19 you will soon notice that you can't use two different configuration files without the
24 We have thought of another way of dealing with this: network names.
25 This means that you call
29 option, which will assign a name to this daemon.
32 The effect of this is that the daemon will set its configuration root to
33 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa / ,
36 is your argument to the
39 You'll notice that messages appear in syslog as coming from
40 .Nm tincd. Ns Ar NETNAME .
43 However, it is not strictly necessary that you call tinc with the
46 In this case, the network name would just be empty,
47 and it will be used as such.
49 now looks for files in
50 .Pa @sysconfdir@/tinc/ ,
52 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa / ;
53 the configuration file should be
54 .Pa @sysconfdir@/tinc/tinc.conf ,
55 and the host configuration files are now expected to be in
56 .Pa @sysconfdir@/tinc/hosts/ .
59 But it is highly recommended that you use this feature of
61 because it will be so much clearer whom your daemon talks to.
62 Hence, we will assume that you use it.
65 Each tinc daemon should have a name that is unique in the network which it will be part of.
66 The name will be used by other tinc daemons for identification.
67 The name has to be declared in the
68 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc.conf
73 choose something that will give unique and easy to remember names to your tinc daemon(s).
74 You could try things like hostnames, owner surnames or location names.
76 .Sh PUBLIC/PRIVATE KEYS
79 to generate public/private keypairs.
80 It will generate two keys.
81 The private key should be stored in a separate file
82 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /rsa_key.priv
85 stands for the network (see
88 The public key should be stored in the host configuration file
89 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /hosts/ Ns Va NAME
92 stands for the name of the local tinc daemon (see
95 .Sh SERVER CONFIGURATION
96 The server configuration of the daemon is done in the file
97 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc.conf .
98 This file consists of comments (lines started with a
100 or assignments in the form of:
103 .Va Variable Li = Ar Value .
106 The variable names are case insensitive, and any spaces, tabs,
107 newlines and carriage returns are ignored.
108 Note: it is not required that you put in the
110 sign, but doing so improves readability.
111 If you leave it out, remember to replace it with at least one space character.
114 The server configuration is complemented with host specific configuration (see the next section).
115 Although all configuration options for the local host listed in this document can also be put in
116 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc.conf ,
117 it is recommended to put host specific configuration options in the host configuration file,
118 as this makes it easy to exchange with other nodes.
121 Here are all valid variables, listed in alphabetical order.
122 The default value is given between parentheses.
123 .Bl -tag -width indent
125 .It Va AddressFamily Li = ipv4 | ipv6 | any Pq any
126 This option affects the address family of listening and outgoing sockets.
129 is selected, then depending on the operating system both IPv4 and IPv6 or just
130 IPv6 listening sockets will be created.
132 .It Va BindToAddress Li = Ar address Bq experimental
133 If your computer has more than one IPv4 or IPv6 address,
135 will by default listen on all of them for incoming connections.
138 variables may be specified,
139 in which case listening sockets for each specified address are made.
142 This option may not work on all platforms.
144 .It Va BindToInterface Li = Ar interface Bq experimental
145 If your computer has more than one network interface,
147 will by default listen on all of them for incoming connections.
148 It is possible to bind only to a single interface with this variable.
151 This option may not work on all platforms.
153 .It Va Broadcast Li = yes | no Po yes Pc Bq experimental
154 When disabled, tinc will drop all broadcast and multicast packets, in both router and switch mode.
156 .It Va ConnectTo Li = Ar name
157 Specifies which other tinc daemon to connect to on startup.
160 variables may be specified,
161 in which case outgoing connections to each specified tinc daemon are made.
162 The names should be known to this tinc daemon
163 (i.e., there should be a host configuration file for the name on the
168 If you don't specify a host with
171 won't try to connect to other daemons at all,
172 and will instead just listen for incoming connections.
174 .It Va DecrementTTL Li = yes | no Po yes Pc
177 will decrement the Time To Live field in IPv4 packets, or the Hop Limit field in IPv6 packets,
178 before forwarding a received packet to the virtual network device or to another node,
179 and will drop packets that have a TTL value of zero,
180 in which case it will send an ICMP Time Exceeded packet back.
182 .It Va Device Li = Ar device Po Pa /dev/tap0 , Pa /dev/net/tun No or other depending on platform Pc
183 The virtual network device to use.
185 will automatically detect what kind of device it is.
186 Note that you can only use one device per daemon.
191 The info pages of the tinc package contain more information
192 about configuring the virtual network device.
194 .It Va DeviceType Li = Ar type Pq platform dependent
195 The type of the virtual network device.
196 Tinc will normally automatically select the right type of tun/tap interface, and this option should not be used.
197 However, this option can be used to select one of the special interface types, if support for them is compiled in.
198 .Bl -tag -width indent
201 Use a dummy interface.
202 No packets are ever read or written to a virtual network device.
203 Useful for testing, or when setting up a node that only forwards packets for other nodes.
206 Open a raw socket, and bind it to a pre-existing
209 All packets are read from this interface.
210 Packets received for the local node are written to the raw socket.
211 However, at least on Linux, the operating system does not process IP packets destined for the local host.
213 .It uml Pq not compiled in by default
214 Create a UNIX socket with the filename specified by
217 .Pa @localstatedir@/run/ Ns Ar NETNAME Ns Pa .umlsocket
220 will wait for a User Mode Linux instance to connect to this socket.
222 .It vde Pq not compiled in by default
223 Uses the libvdeplug library to connect to a Virtual Distributed Ethernet switch,
224 using the UNIX socket specified by
227 .Pa @localstatedir@/run/vde.ctl
231 Also, in case tinc does not seem to correctly interpret packets received from the virtual network device,
232 it can be used to change the way packets are interpreted:
234 .Bl -tag -width indent
236 .It tun Pq BSD and Linux
238 Depending on the platform, this can either be with or without an address family header (see below).
241 Set type to tun without an address family header.
242 Tinc will expect packets read from the virtual network device to start with an IP header.
243 On some platforms IPv6 packets cannot be read from or written to the device in this mode.
246 Set type to tun with an address family header.
247 Tinc will expect packets read from the virtual network device
248 to start with a four byte header containing the address family,
249 followed by an IP header.
250 This mode should support both IPv4 and IPv6 packets.
252 .It tap Pq BSD and Linux
254 Tinc will expect packets read from the virtual network device
255 to start with an Ethernet header.
258 .It Va DirectOnly Li = yes | no Po no Pc Bq experimental
259 When this option is enabled, packets that cannot be sent directly to the destination node,
260 but which would have to be forwarded by an intermediate node, are dropped instead.
261 When combined with the IndirectData option,
262 packets for nodes for which we do not have a meta connection with are also dropped.
264 .It Va Forwarding Li = off | internal | kernel Po internal Pc Bq experimental
265 This option selects the way indirect packets are forwarded.
266 .Bl -tag -width indent
269 Incoming packets that are not meant for the local node,
270 but which should be forwarded to another node, are dropped.
273 Incoming packets that are meant for another node are forwarded by tinc internally.
276 This is the default mode, and unless you really know you need another forwarding mode, don't change it.
279 Incoming packets are always sent to the TUN/TAP device, even if the packets are not for the local node.
280 This is less efficient, but allows the kernel to apply its routing and firewall rules on them,
281 and can also help debugging.
284 .It Va GraphDumpFile Li = Ar filename Bq experimental
285 If this option is present,
287 will dump the current network graph to the file
289 every minute, unless there were no changes to the graph.
290 The file is in a format that can be read by graphviz tools.
293 starts with a pipe symbol |,
294 then the rest of the filename is interpreted as a shell command
295 that is executed, the graph is then sent to stdin.
297 .It Va Hostnames Li = yes | no Pq no
298 This option selects whether IP addresses (both real and on the VPN) should
299 be resolved. Since DNS lookups are blocking, it might affect tinc's
300 efficiency, even stopping the daemon for a few seconds every time it does
301 a lookup if your DNS server is not responding.
304 This does not affect resolving hostnames to IP addresses from the
305 host configuration files.
307 .It Va IffOneQueue Li = yes | no Po no Pc Bq experimental
308 (Linux only) Set IFF_ONE_QUEUE flag on TUN/TAP devices.
310 .It Va Interface Li = Ar interface
311 Defines the name of the interface corresponding to the virtual network device.
312 Depending on the operating system and the type of device this may or may not actually set the name of the interface.
313 Under Windows, this variable is used to select which network interface will be used.
316 this variable is almost always already correctly set.
318 .It Va KeyExpire Li = Ar seconds Pq 3600
319 This option controls the period the encryption keys used to encrypt the data are valid.
320 It is common practice to change keys at regular intervals to make it even harder for crackers,
321 even though it is thought to be nearly impossible to crack a single key.
323 .It Va MACExpire Li = Ar seconds Pq 600
324 This option controls the amount of time MAC addresses are kept before they are removed.
325 This only has effect when
330 .It Va MaxTimeout Li = Ar seconds Pq 900
331 This is the maximum delay before trying to reconnect to other tinc daemons.
333 .It Va Mode Li = router | switch | hub Pq router
334 This option selects the way packets are routed to other daemons.
335 .Bl -tag -width indent
340 variables in the host configuration files will be used to form a routing table.
341 Only unicast packets of routable protocols (IPv4 and IPv6) are supported in this mode.
344 This is the default mode, and unless you really know you need another mode, don't change it.
347 In this mode the MAC addresses of the packets on the VPN will be used to
348 dynamically create a routing table just like an Ethernet switch does.
349 Unicast, multicast and broadcast packets of every protocol that runs over Ethernet are supported in this mode
350 at the cost of frequent broadcast ARP requests and routing table updates.
353 This mode is primarily useful if you want to bridge Ethernet segments.
356 This mode is almost the same as the switch mode, but instead
357 every packet will be broadcast to the other daemons
358 while no routing table is managed.
361 .It Va Name Li = Ar name Bq required
362 This is the name which identifies this tinc daemon.
363 It must be unique for the virtual private network this daemon will connect to.
365 .It Va PingInterval Li = Ar seconds Pq 60
366 The number of seconds of inactivity that
368 will wait before sending a probe to the other end.
370 .It Va PingTimeout Li = Ar seconds Pq 5
371 The number of seconds to wait for a response to pings or to allow meta
372 connections to block. If the other end doesn't respond within this time,
373 the connection is terminated,
374 and the others will be notified of this.
376 .It Va PriorityInheritance Li = yes | no Po no Pc Bq experimental
377 When this option is enabled the value of the TOS field of tunneled IPv4 packets
378 will be inherited by the UDP packets that are sent out.
380 .It Va PrivateKey Li = Ar key Bq obsolete
381 The private RSA key of this tinc daemon.
382 It will allow this tinc daemon to authenticate itself to other daemons.
384 .It Va PrivateKeyFile Li = Ar filename Po Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /rsa_key.priv Pc
385 The file in which the private RSA key of this tinc daemon resides.
386 Note that there must be exactly one of
390 specified in the configuration file.
392 .It Va ProcessPriority Li = low | normal | high
393 When this option is used the priority of the tincd process will be adjusted.
394 Increasing the priority may help to reduce latency and packet loss on the VPN.
396 .It Va ReplayWindow Li = Ar bytes Pq 16
397 This is the size of the replay tracking window for each remote node, in bytes.
398 The window is a bitfield which tracks 1 packet per bit, so for example
399 the default setting of 16 will track up to 128 packets in the window. In high
400 bandwidth scenarios, setting this to a higher value can reduce packet loss from
401 the interaction of replay tracking with underlying real packet loss and/or
402 reordering. Setting this to zero will disable replay tracking completely and
403 pass all traffic, but leaves tinc vulnerable to replay-based attacks on your
406 .It Va StrictSubnets Li = yes | no Po no Pc Bq experimental
407 When this option is enabled tinc will only use Subnet statements which are
408 present in the host config files in the local
409 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /hosts/
412 .It Va TunnelServer Li = yes | no Po no Pc Bq experimental
413 When this option is enabled tinc will no longer forward information between other tinc daemons,
414 and will only allow connections with nodes for which host config files are present in the local
415 .Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /hosts/
417 Setting this options also implicitly sets StrictSubnets.
419 .It Va UDPRcvBuf Li = Ar bytes Pq OS default
420 Sets the socket receive buffer size for the UDP socket, in bytes.
421 If unset, the default buffer size will be used by the operating system.
423 .It Va UDPSndBuf Li = Ar bytes Pq OS default
424 Sets the socket send buffer size for the UDP socket, in bytes.
425 If unset, the default buffer size will be used by the operating system.
428 .Sh HOST CONFIGURATION FILES
429 The host configuration files contain all information needed
430 to establish a connection to those hosts.
431 A host configuration file is also required for the local tinc daemon,
432 it will use it to read in it's listen port, public key and subnets.
435 The idea is that these files are portable.
436 You can safely mail your own host configuration file to someone else.
437 That other person can then copy it to his own hosts directory,
438 and now his tinc daemon will be able to connect to your tinc daemon.
439 Since host configuration files only contain public keys,
440 no secrets are revealed by sending out this information.
441 .Bl -tag -width indent
443 .It Va Address Li = Ar address Oo port Oc Bq recommended
444 The IP address or hostname of this tinc daemon on the real network.
445 This will only be used when trying to make an outgoing connection to this tinc daemon.
446 Optionally, a port can be specified to use for this address.
449 variables can be specified, in which case each address will be tried until a working
450 connection has been established.
452 .It Va Cipher Li = Ar cipher Pq blowfish
453 The symmetric cipher algorithm used to encrypt UDP packets.
454 Any cipher supported by OpenSSL is recognised.
455 Furthermore, specifying
457 will turn off packet encryption.
458 It is best to use only those ciphers which support CBC mode.
460 .It Va ClampMSS Li = yes | no Pq yes
461 This option specifies whether tinc should clamp the maximum segment size (MSS)
462 of TCP packets to the path MTU. This helps in situations where ICMP
463 Fragmentation Needed or Packet too Big messages are dropped by firewalls.
465 .It Va Compression Li = Ar level Pq 0
466 This option sets the level of compression used for UDP packets.
467 Possible values are 0 (off), 1 (fast zlib) and any integer up to 9 (best zlib),
468 10 (fast lzo) and 11 (best lzo).
470 .It Va Digest Li = Ar digest Pq sha1
471 The digest algorithm used to authenticate UDP packets.
472 Any digest supported by OpenSSL is recognised.
473 Furthermore, specifying
475 will turn off packet authentication.
477 .It Va IndirectData Li = yes | no Pq no
478 This option specifies whether other tinc daemons besides the one you specified with
480 can make a direct connection to you.
481 This is especially useful if you are behind a firewall
482 and it is impossible to make a connection from the outside to your tinc daemon.
483 Otherwise, it is best to leave this option out or set it to no.
485 .It Va MACLength Li = Ar length Pq 4
486 The length of the message authentication code used to authenticate UDP packets.
489 up to the length of the digest produced by the digest algorithm.
491 .It Va PMTU Li = Ar mtu Po 1514 Pc
492 This option controls the initial path MTU to this node.
494 .It Va PMTUDiscovery Li = yes | no Po yes Pc
495 When this option is enabled, tinc will try to discover the path MTU to this node.
496 After the path MTU has been discovered, it will be enforced on the VPN.
498 .It Va Port Li = Ar port Pq 655
499 The port number on which this tinc daemon is listening for incoming connections,
500 which is used if no port number is specified in an
504 .It Va PublicKey Li = Ar key Bq obsolete
505 The public RSA key of this tinc daemon.
506 It will be used to cryptographically verify it's identity and to set up a secure connection.
508 .It Va PublicKeyFile Li = Ar filename Bq obsolete
509 The file in which the public RSA key of this tinc daemon resides.
512 From version 1.0pre4 on
514 will store the public key directly into the host configuration file in PEM format,
515 the above two options then are not necessary.
516 Either the PEM format is used, or exactly one of the above two options must be specified
517 in each host configuration file,
518 if you want to be able to establish a connection with that host.
520 .It Va Subnet Li = Ar address Ns Op Li / Ns Ar prefixlength Ns Op Li # Ns Ar weight
521 The subnet which this tinc daemon will serve.
523 tries to look up which other daemon it should send a packet to by searching the appropriate subnet.
524 If the packet matches a subnet,
525 it will be sent to the daemon who has this subnet in his host configuration file.
528 variables can be specified.
531 Subnets can either be single MAC, IPv4 or IPv6 addresses,
532 in which case a subnet consisting of only that single address is assumed,
533 or they can be a IPv4 or IPv6 network address with a prefixlength.
534 Shorthand notations are not supported.
535 For example, IPv4 subnets must be in a form like 192.168.1.0/24,
536 where 192.168.1.0 is the network address and 24 is the number of bits set in the netmask.
537 Note that subnets like 192.168.1.1/24 are invalid!
538 Read a networking HOWTO/FAQ/guide if you don't understand this.
539 IPv6 subnets are notated like fec0:0:0:1:0:0:0:0/64.
540 MAC addresses are notated like 0:1a:2b:3c:4d:5e.
543 A Subnet can be given a weight to indicate its priority over identical Subnets
544 owned by different nodes. The default weight is 10. Lower values indicate
545 higher priority. Packets will be sent to the node with the highest priority,
546 unless that node is not reachable, in which case the node with the next highest
547 priority will be tried, and so on.
549 .It Va TCPOnly Li = yes | no Pq no Bq obsolete
550 If this variable is set to yes,
551 then the packets are tunnelled over the TCP connection instead of a UDP connection.
552 This is especially useful for those who want to run a tinc daemon
553 from behind a masquerading firewall,
554 or if UDP packet routing is disabled somehow.
555 Setting this options also implicitly sets IndirectData.
558 Since version 1.0.10, tinc will automatically detect whether communication via
559 UDP is possible or not.
563 Apart from reading the server and host configuration files,
564 tinc can also run scripts at certain moments.
565 Under Windows (not Cygwin), the scripts should have the extension
567 .Bl -tag -width indent
569 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc-up
570 This is the most important script.
571 If it is present it will be executed right after the tinc daemon has been started and has connected to the virtual network device.
572 It should be used to set up the corresponding network interface,
573 but can also be used to start other things.
574 Under Windows you can use the Network Connections control panel instead of creating this script.
576 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc-down
577 This script is started right before the tinc daemon quits.
579 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /hosts/ Ns Ar HOST Ns Pa -up
580 This script is started when the tinc daemon with name
584 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /hosts/ Ns Ar HOST Ns Pa -down
585 This script is started when the tinc daemon with name
589 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /host-up
590 This script is started when any host becomes reachable.
592 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /host-down
593 This script is started when any host becomes unreachable.
595 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /subnet-up
596 This script is started when a Subnet becomes reachable.
597 The Subnet and the node it belongs to are passed in environment variables.
599 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /subnet-down
600 This script is started when a Subnet becomes unreachable.
604 The scripts are started without command line arguments, but can make use of certain environment variables.
605 Under UNIX like operating systems the names of environment variables must be preceded by a
610 files, they have to be put between
613 .Bl -tag -width indent
616 If a netname was specified, this environment variable contains it.
619 Contains the name of this tinc daemon.
622 Contains the name of the virtual network device that tinc uses.
625 Contains the name of the virtual network interface that tinc uses.
626 This should be used for commands like
630 When a host becomes (un)reachable, this is set to its name.
631 If a subnet becomes (un)reachable, this is set to the owner of that subnet.
634 When a host becomes (un)reachable, this is set to its real address.
637 When a host becomes (un)reachable, this is set to the port number it uses for communication with other tinc daemons.
640 When a subnet becomes (un)reachable, this is set to the subnet.
643 When a subnet becomes (un)reachable, this is set to the subnet weight.
647 The most important files are:
648 .Bl -tag -width indent
650 .It Pa @sysconfdir@/tinc/
651 The top directory for configuration files.
653 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc.conf
654 The default name of the server configuration file for net
657 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /hosts/
658 Host configuration files are kept in this directory.
660 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc-up
661 If an executable file with this name exists,
662 it will be executed right after the tinc daemon has connected to the virtual network device.
663 It can be used to set up the corresponding network interface.
665 .It Pa @sysconfdir@/tinc/ Ns Ar NETNAME Ns Pa /tinc-down
666 If an executable file with this name exists,
667 it will be executed right before the tinc daemon is going to close
668 its connection to the virtual network device.
673 .Pa http://www.tinc-vpn.org/ ,
674 .Pa http://www.linuxdoc.org/LDP/nag2/ .
677 The full documentation for
679 is maintained as a Texinfo manual.
680 If the info and tinc programs are properly installed at your site, the command
682 should give you access to the complete manual.
686 comes with ABSOLUTELY NO WARRANTY.
687 This is free software, and you are welcome to redistribute it under certain conditions;
688 see the file COPYING for details.