N2n is a light VPN software which make it easy to create virtual networks bypassing intermediate firewalls. In order to start using N2N, two elements are required:
A virtual network shared between multiple edge nodes in n2n is called a *community*. A single supernode can relay multiple communities and a single PC can be part of multiple communities at the same time. An encryption key can be used by the edge nodes to encrypt the packets within their community.
Some linux distributions already provide n2n as a package so a simple `sudo apt-get install n2n` will do the work. Alternatively, up to date packages for most distributions are available on [ntop repositories](http://packages.ntop.org/).
**IMPORTANT** It is strongly adviced to choose a custom community name (-c) and a secret encryption key (-k) in order to prevent other users to connect to your PC. For privacy and to reduce the above server load, it is also suggested to set up a custom supernode as exmplained below.
You can create your own infrastructure by setting up a supernode on a public server (e.g. a VPS). You just need to open a single port (1234 in the example below) on your firewall (usually iptables).
Now the supernode service should be up and running on port 1234. On your edge nodes you can now specify `-l your_supernode_ip:1234` to use it. All the edge nodes must use the same supernode.