Tinc is a meshing VPN daemon. It allows multiple parties to connect and discover each other independently, while minimizing points of failure. Tinc will use a bunch of nodes to build the network graph, which in return all nodes use to learn addresses from each other. If nodes want to reach each other, they establish a direct connection. If that is not possible traffic may be routed via a shared neighbor. Tinc is most notably powering the Freifunk communitys ICVPN (in L2/Switch-Mode) and ChaosVPN (in L3/Router-Mode).
Tinc primarily operates in two modes: router and switch. A third mode, the hub mode, exists, but it's just a dumb router mode that keeps no routing table and broadcasts everything - don't use it. In Router mode each peer announces the addresses/subnets it serves. Tinc will spawn an interface on which it will act as a L3 network, routing according to announcements. This is the default mode, but it is unsuitable for dn42, because you cannot influence how tinc will route to a certain network. In Switch mode tinc will act like a L2 network, in which the routing table reflects the peers mac addresses.
One advantage of tinc is that you can have multiple peering over the same VPN configuration by opening multiple connections.
dn42_yourpeer your_host switch remote_host
Tinc requires to add manually ip addresses and routes to the tap/tun interfaces. On startup it will execute
/etc/tinc/dn42_yourpeer/tinc-up if it exists and is executable:
#!/bin/sh # set the interface up # add transfer networks # add routes
For authentication tinc uses public key authentication instead of certificates or pre-shared keys. For each key tinc should connect to or allow to connect, a file with the name of the peer in tincd -n twwh -K is required. To generate a public/private key pair use:
Import for each other party the key like this
<fqdn/ip_addr> <port|655> -----BEGIN RSA PUBLIC KEY----- MIIBCgKCAQEAoGeD5b1HKW2UAFpIPayxsOOYx5qC0oHrJnvcPH33jnDBGiOYJ9ma /wJE6i569fzKWOUdLHrN5dVzD/Q5zjMOwJf3rmcerS0oAFTxKDj /lSNMIN//W66mM258BLo1XgEraUx5RcJ4hTxawhNTn0NTJVCbfUX6e5 tcJpbgbYRzBTUPdSL3OB8k0qlmFI2ZYTnCzOSpgxRQARIB1ecoqOYVxQISK2pzxi MHQQlVbquwldaKiVoj7tD7PFW4oQxpiMHZnHIA6dnZCsT3ktTOzCjhf2XMi8o8u5 /w1z+PrTYquoQIDAQAB -----END RSA PUBLIC KEY-----
Fun with tinc-pre
The current development version (which is pretty stable by the way), allow to bootstrap networks using invitation urls. Instead of rsa keys it uses ed25519 keys. To keep backwards compatibility with the tinc 1.0 release you need rsa keys, if you don't need that only generate ed25519 keys. It also introduces the tinc binary in addition to tincd, which allows tinc to be configured via an readline interface.
- Archlinux: install tinc-pre from AUR
- Debian: follow these instructions to get a package
- Freebsd: Use this port repo
Set up a new tinc network
# tinc -n dn42_yourpeer init dn42_yourself
Invite your peering partner. Tinc will print the invitaion which you need to copy to your peering partner.
On the other node you can join by using:
This node will then automatically generate configuration, private/public keys and will exchange this key with the other node on connection.
Remember to still set up your tinc-up script.