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4.4.1 Main configuration variables

AddressFamily = <ipv4|ipv6|any> (any)

This option affects the address family of listening and outgoing sockets. If any is selected, then depending on the operating system both IPv4 and IPv6 or just IPv6 listening sockets will be created.

AutoConnect = <yes|no> (yes)

If set to yes, tinc will automatically set up meta connections to other nodes, without requiring ConnectTo variables.

BindToAddress = <address> [<port>]

This is the same as ListenAddress, however the address given with the BindToAddress option will also be used for outgoing connections. This is useful if your computer has more than one IPv4 or IPv6 address, and you want tinc to only use a specific one for outgoing packets.

BindToInterface = <interface> [experimental]

If you have more than one network interface in your computer, tinc will by default listen on all of them for incoming connections. It is possible to bind tinc to a single interface like eth0 or ppp0 with this variable.

This option may not work on all platforms. Also, on some platforms it will not actually bind to an interface, but rather to the address that the interface has at the moment a socket is created.

Broadcast = <no | mst | direct> (mst) [experimental]

This option selects the way broadcast packets are sent to other daemons. NOTE: all nodes in a VPN must use the same Broadcast mode, otherwise routing loops can form.

no

Broadcast packets are never sent to other nodes.

mst

Broadcast packets are sent and forwarded via the VPN’s Minimum Spanning Tree. This ensures broadcast packets reach all nodes.

direct

Broadcast packets are sent directly to all nodes that can be reached directly. Broadcast packets received from other nodes are never forwarded. If the IndirectData option is also set, broadcast packets will only be sent to nodes which we have a meta connection to.

BroadcastSubnet = address[/prefixlength]

Declares a broadcast subnet. Any packet with a destination address falling into such a subnet will be routed as a broadcast (provided all nodes have it declared). This is most useful to declare subnet broadcast addresses (e.g. 10.42.255.255), otherwise tinc won’t know what to do with them.

Note that global broadcast addresses (MAC ff:ff:ff:ff:ff:ff, IPv4 255.255.255.255), as well as multicast space (IPv4 224.0.0.0/4, IPv6 ff00::/8) are always considered broadcast addresses and don’t need to be declared.

ConnectTo = <name>

Specifies which other tinc daemon to connect to on startup. Multiple ConnectTo variables may be specified, in which case outgoing connections to each specified tinc daemon are made. The names should be known to this tinc daemon (i.e., there should be a host configuration file for the name on the ConnectTo line).

If you don’t specify a host with ConnectTo and have disabled AutoConnect, tinc won’t try to connect to other daemons at all, and will instead just listen for incoming connections.

DecrementTTL = <yes | no> (no) [experimental]

When enabled, tinc will decrement the Time To Live field in IPv4 packets, or the Hop Limit field in IPv6 packets, before forwarding a received packet to the virtual network device or to another node, and will drop packets that have a TTL value of zero, in which case it will send an ICMP Time Exceeded packet back.

Do not use this option if you use switch mode and want to use IPv6.

Device = <device> (/dev/tap0, /dev/net/tun or other depending on platform)

The virtual network device to use. Tinc will automatically detect what kind of device it is. Note that you can only use one device per daemon. Under Windows, use Interface instead of Device. Note that you can only use one device per daemon. See also Device files.

DeviceStandby = <yes | no> (no)

When disabled, tinc calls tinc-up on startup, and tinc-down on shutdown. When enabled, tinc will only call tinc-up when at least one node is reachable, and will call tinc-down as soon as no nodes are reachable. On Windows, this also determines when the virtual network interface "cable" is "plugged".

DeviceType = <type> (platform dependent)

The type of the virtual network device. Tinc will normally automatically select the right type of tun/tap interface, and this option should not be used. However, this option can be used to select one of the special interface types, if support for them is compiled in.

dummy

Use a dummy interface. No packets are ever read or written to a virtual network device. Useful for testing, or when setting up a node that only forwards packets for other nodes.

raw_socket

Open a raw socket, and bind it to a pre-existing Interface (eth0 by default). All packets are read from this interface. Packets received for the local node are written to the raw socket. However, at least on Linux, the operating system does not process IP packets destined for the local host.

multicast

Open a multicast UDP socket and bind it to the address and port (separated by spaces) and optionally a TTL value specified using Device. Packets are read from and written to this multicast socket. This can be used to connect to UML, QEMU or KVM instances listening on the same multicast address. Do NOT connect multiple tinc daemons to the same multicast address, this will very likely cause routing loops. Also note that this can cause decrypted VPN packets to be sent out on a real network if misconfigured.

fd

Use a file descriptor. All packets are read from this interface. Packets received for the local node are written to it.

uml (not compiled in by default)

Create a UNIX socket with the filename specified by Device, or /var/run/netname.umlsocket if not specified. Tinc will wait for a User Mode Linux instance to connect to this socket.

vde (not compiled in by default)

Uses the libvdeplug library to connect to a Virtual Distributed Ethernet switch, using the UNIX socket specified by Device, or /var/run/vde.ctl if not specified.

Also, in case tinc does not seem to correctly interpret packets received from the virtual network device, it can be used to change the way packets are interpreted:

tun (BSD and Linux)

Set type to tun. Depending on the platform, this can either be with or without an address family header (see below).

tunnohead (BSD)

Set type to tun without an address family header. Tinc will expect packets read from the virtual network device to start with an IP header. On some platforms IPv6 packets cannot be read from or written to the device in this mode.

tunifhead (BSD)

Set type to tun with an address family header. Tinc will expect packets read from the virtual network device to start with a four byte header containing the address family, followed by an IP header. This mode should support both IPv4 and IPv6 packets.

utun (OS X)

Set type to utun. This is only supported on OS X version 10.6.8 and higher, but doesn’t require the tuntaposx module. This mode should support both IPv4 and IPv6 packets.

tap (BSD and Linux)

Set type to tap. Tinc will expect packets read from the virtual network device to start with an Ethernet header.

DirectOnly = <yes|no> (no) [experimental]

When this option is enabled, packets that cannot be sent directly to the destination node, but which would have to be forwarded by an intermediate node, are dropped instead. When combined with the IndirectData option, packets for nodes for which we do not have a meta connection with are also dropped.

Ed25519PrivateKeyFile = <path> (/etc/tinc/netname/ed25519_key.priv)

The file in which the private Ed25519 key of this tinc daemon resides. This is only used if ExperimentalProtocol is enabled.

ExperimentalProtocol = <yes|no> (yes)

When this option is enabled, the SPTPS protocol will be used when connecting to nodes that also support it. Ephemeral ECDH will be used for key exchanges, and Ed25519 will be used instead of RSA for authentication. When enabled, an Ed25519 key must have been generated before with ‘tinc generate-ed25519-keys’.

Forwarding = <off|internal|kernel> (internal) [experimental]

This option selects the way indirect packets are forwarded.

off

Incoming packets that are not meant for the local node, but which should be forwarded to another node, are dropped.

internal

Incoming packets that are meant for another node are forwarded by tinc internally.

This is the default mode, and unless you really know you need another forwarding mode, don’t change it.

kernel

Incoming packets using the legacy protocol are always sent to the TUN/TAP device, even if the packets are not for the local node. This is less efficient, but allows the kernel to apply its routing and firewall rules on them, and can also help debugging. Incoming packets using the SPTPS protocol are dropped, since they are end-to-end encrypted.

FWMark = <value> (0) [experimental]

When set to a non-zero value, all TCP and UDP sockets created by tinc will use the given value as the firewall mark. This can be used for mark-based routing or for packet filtering. This option is currently only supported on Linux.

Hostnames = <yes|no> (no)

This option selects whether IP addresses (both real and on the VPN) should be resolved. Since DNS lookups are blocking, it might affect tinc’s efficiency, even stopping the daemon for a few seconds every time it does a lookup if your DNS server is not responding.

This does not affect resolving hostnames to IP addresses from the configuration file, but whether hostnames should be resolved while logging.

Interface = <interface>

Defines the name of the interface corresponding to the virtual network device. Depending on the operating system and the type of device this may or may not actually set the name of the interface. Under Windows, this variable is used to select which network interface will be used. If you specified a Device, this variable is almost always already correctly set.

ListenAddress = <address> [<port>]

If your computer has more than one IPv4 or IPv6 address, tinc will by default listen on all of them for incoming connections. This option can be used to restrict which addresses tinc listens on. Multiple ListenAddress variables may be specified, in which case listening sockets for each specified address are made.

If no port is specified, the socket will listen on the port specified by the Port option, or to port 655 if neither is given. To only listen on a specific port but not to a specific address, use "*" for the address.

LocalDiscovery = <yes | no> (no)

When enabled, tinc will try to detect peers that are on the same local network. This will allow direct communication using LAN addresses, even if both peers are behind a NAT and they only ConnectTo a third node outside the NAT, which normally would prevent the peers from learning each other’s LAN address.

Currently, local discovery is implemented by sending some packets to the local address of the node during UDP discovery. This will not work with old nodes that don’t transmit their local address.

LogLevel = <level> (0)

This option controls the verbosity of the logging. See Debug levels.

Mode = <router|switch|hub> (router)

This option selects the way packets are routed to other daemons.

router

In this mode Subnet variables in the host configuration files will be used to form a routing table. Only packets of routable protocols (IPv4 and IPv6) are supported in this mode.

This is the default mode, and unless you really know you need another mode, don’t change it.

switch

In this mode the MAC addresses of the packets on the VPN will be used to dynamically create a routing table just like an Ethernet switch does. Unicast, multicast and broadcast packets of every protocol that runs over Ethernet are supported in this mode at the cost of frequent broadcast ARP requests and routing table updates.

This mode is primarily useful if you want to bridge Ethernet segments.

hub

This mode is almost the same as the switch mode, but instead every packet will be broadcast to the other daemons while no routing table is managed.

InvitationExpire = <seconds> (604800)

This option controls the time invitations are valid.

KeyExpire = <seconds> (3600)

This option controls the time the encryption keys used to encrypt the data are valid. It is common practice to change keys at regular intervals to make it even harder for crackers, even though it is thought to be nearly impossible to crack a single key.

MACExpire = <seconds> (600)

This option controls the amount of time MAC addresses are kept before they are removed. This only has effect when Mode is set to "switch".

MaxConnectionBurst = <count> (100)

This option controls how many connections tinc accepts in quick succession. If there are more connections than the given number in a short time interval, tinc will reduce the number of accepted connections to only one per second, until the burst has passed.

Name = <name> [required]

This is a symbolic name for this connection. The name must consist only of alfanumeric and underscore characters (a-z, A-Z, 0-9 and _), and is case sensitive.

If Name starts with a $, then the contents of the environment variable that follows will be used. In that case, invalid characters will be converted to underscores. If Name is $HOST, but no such environment variable exist, the hostname will be read using the gethostname() system call.

PingInterval = <seconds> (60)

The number of seconds of inactivity that tinc will wait before sending a probe to the other end.

PingTimeout = <seconds> (5)

The number of seconds to wait for a response to pings or to allow meta connections to block. If the other end doesn’t respond within this time, the connection is terminated, and the others will be notified of this.

PriorityInheritance = <yes|no> (no) [experimental]

When this option is enabled the value of the TOS field of tunneled IPv4 packets will be inherited by the UDP packets that are sent out.

PrivateKey = <key> [obsolete]

This is the RSA private key for tinc. However, for safety reasons it is advised to store private keys of any kind in separate files. This prevents accidental eavesdropping if you are editing the configuration file.

PrivateKeyFile = <path> (/etc/tinc/netname/rsa_key.priv)

This is the full path name of the RSA private key file that was generated by ‘tinc generate-keys’. It must be a full path, not a relative directory.

ProcessPriority = <low|normal|high>

When this option is used the priority of the tincd process will be adjusted. Increasing the priority may help to reduce latency and packet loss on the VPN.

Proxy = socks4 | socks5 | http | exec ... [experimental]

Use a proxy when making outgoing connections. The following proxy types are currently supported:

socks4 <address> <port> [<username>]

Connects to the proxy using the SOCKS version 4 protocol. Optionally, a username can be supplied which will be passed on to the proxy server.

socks5 <address> <port> [<username> <password>]

Connect to the proxy using the SOCKS version 5 protocol. If a username and password are given, basic username/password authentication will be used, otherwise no authentication will be used.

http <address> <port>

Connects to the proxy and sends a HTTP CONNECT request.

exec <command>

Executes the given command which should set up the outgoing connection. The environment variables NAME, NODE, REMOTEADDRES and REMOTEPORT are available.

ReplayWindow = <bytes> (32)

This is the size of the replay tracking window for each remote node, in bytes. The window is a bitfield which tracks 1 packet per bit, so for example the default setting of 32 will track up to 256 packets in the window. In high bandwidth scenarios, setting this to a higher value can reduce packet loss from the interaction of replay tracking with underlying real packet loss and/or reordering. Setting this to zero will disable replay tracking completely and pass all traffic, but leaves tinc vulnerable to replay-based attacks on your traffic.

StrictSubnets = <yes|no> (no) [experimental]

When this option is enabled tinc will only use Subnet statements which are present in the host config files in the local /etc/tinc/netname/hosts/ directory. Subnets learned via connections to other nodes and which are not present in the local host config files are ignored.

TunnelServer = <yes|no> (no) [experimental]

When this option is enabled tinc will no longer forward information between other tinc daemons, and will only allow connections with nodes for which host config files are present in the local /etc/tinc/netname/hosts/ directory. Setting this options also implicitly sets StrictSubnets.

UDPDiscovery = <yes|no> (yes)

When this option is enabled tinc will try to establish UDP connectivity to nodes, using TCP while it determines if a node is reachable over UDP. If it is disabled, tinc always assumes a node is reachable over UDP. Note that tinc will never use UDP with nodes that have TCPOnly enabled.

UDPDiscoveryKeepaliveInterval = <seconds> (9)

The minimum amount of time between sending UDP ping datagrams to check UDP connectivity once it has been established. Note that these pings are large, since they are used to verify link MTU as well.

UDPDiscoveryInterval = <seconds> (2)

The minimum amount of time between sending UDP ping datagrams to try to establish UDP connectivity.

UDPDiscoveryTimeout = <seconds> (30)

If tinc doesn’t receive any UDP ping replies over the specified interval, it will assume UDP communication is broken and will fall back to TCP.

UDPInfoInterval = <seconds> (5)

The minimum amount of time between sending periodic updates about UDP addresses, which are mostly useful for UDP hole punching.

UDPRcvBuf = <bytes> (1048576)

Sets the socket receive buffer size for the UDP socket, in bytes. If set to zero, the default buffer size will be used by the operating system. Note: this setting can have a significant impact on performance, especially raw throughput.

UDPSndBuf = <bytes> (1048576)

Sets the socket send buffer size for the UDP socket, in bytes. If set to zero, the default buffer size will be used by the operating system. Note: this setting can have a significant impact on performance, especially raw throughput.

UPnP = <yes|udponly|no> (no)

If this option is enabled then tinc will search for UPnP-IGD devices on the local network. It will then create and maintain port mappings for tinc’s listening TCP and UDP ports. If set to "udponly", tinc will only create a mapping for its UDP (data) port, not for its TCP (metaconnection) port. Note that tinc must have been built with miniupnpc support for this feature to be available. Furthermore, be advised that enabling this can have security implications, because the miniupnpc library that tinc uses might not be well-hardened with regard to malicious UPnP replies.

UPnPDiscoverWait = <seconds> (5)

The amount of time to wait for replies when probing the local network for UPnP devices.

UPnPRefreshPeriod = <seconds> (5)

How often tinc will re-add the port mapping, in case it gets reset on the UPnP device. This also controls the duration of the port mapping itself, which will be set to twice that duration.


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