10 Tinc is a system to create a virtual ethernet network on top of an existing
11 infrastructure. This infrastructure can be anything from modem lines to
12 gigabit ethernet networks, as long as they talk IP. Once you install and
13 configure tinc, your host will get an extra IP address, just like it would
14 when you stick an extra ethernet card into it. Using this IP address, it can
15 communicate with all hosts in its virtual network using strong encryption.
17 If you install Tinc on a router (and pick your numbers correctly) you can
18 have the router forward all packets. This way you can---instead of
19 connecting hosts---connect entire sites together! Now you need only one
20 outgoing network connection for both internet and intranet.
24 Before you fetch the latest tarball, you might want to check if there's a
25 package for your Linux distribution. One of the main authors is a Debian
26 Developer, so you can expect the Debian packages to be very up to date.
28 The official website for Tinc can be found at http://tinc.nl.linux.org/.
29 There you can find Debian packages, RPM's and of course... the tarball!
30 Since we run Doohickey Linux Pro 1.0, for which no package exists (or
31 indeed the distribution itself) we shall compile the package ourselves.
35 The Tinc source adheres to so many standards it makes you head spin.
36 Even the debug messages have been localized! Amazing. Tinc also comes
37 with a configuration script. If you like to see what is there to
38 configure run ./configure --help | more. If you don't have time for such
41 ./configure --sysconfdir=/etc
43 This will see if your system is nice enough to run tinc on, and will
44 create some Makefiles and other stuff which will together build tinc.
49 The first will do the actual build, the second copies all files into place.
57 The first thing we should do is pick network numbers. Tinc has a very
58 peculiar taste for network numbers, which is caused by the way it routes
59 traffic. However, it turns out to be really handy if you want to use
60 your tinc host as a router for a site.
62 The numbers have to be in a range that is not yet in use in your existing,
63 real network! In this example we will use numbers from the 192.168.0/16
64 range. This is standard CIDR notation for all IP addresses from 192.168.0.0
65 to 192.168.255.255. The /16 means that the first 16 bits form the network
68 In the example we will connect three machines: f00f, fdiv and hlt. We will
69 give each an address, but not just that, also a slice of our address space
72 Host Real address Tinc network
73 ---------------------------------------------------
74 f00f 126.202.37.20 192.168.1.1/24
75 fdiv 126.202.37.81 192.168.2.1/24
76 hlt 103.22.1.218 192.168.3.1/24
78 It is very important that none of the Tinc netmasks overlap! Note how the
79 192.168.0/16 network covers the entire address space of the three hosts.
80 We will refer to the 192.168.0/16 network as the `umbrella' from now on.
81 As you can see we can fit 256 hosts into this umbrella this way, which is
82 also the practical maximum for tinc.
84 Let's create a configuration file for f00f. We have to put it in /etc/tinc,
85 unless you participate in multiple umbrella's (more on that later).