Hamachi is a zero-configuration shareware application capable of establishing direct links between computers that are behind NAT firewalls without requiring reconfiguration (in most cases); in other words, it establishes a connection over the Internet that very closely emulates the connection that would exist if the computers were connected over a local area network. Currently available as a production version for Microsoft Windows and, as beta, for Mac OS X and Linux.
Creating a Hamachi Network
Using Hamachi begins with the creation of a network. You do this by selecting the Networks button and then the Create new network option.
In the Create new network dialog box, you will need to name your network and create a password. The network name should be unique and is limited to 64 characters in length. The password - or pass phrase - should be something that only you know and is very hard to guess - the security of your network is dependent on it. There is no limit to the length of the passphrase. Once you have done this, click Create and the network now appears in the Hamachi client.
Joining a Hamachi Network
The next step is to have other computers join you network. On a computer other than the one used to create the network, click on the Networks button. In the menu that appears, select Join existing network.
The Quick Guide gives you an example network to join, however, in the above example, the name and passphrase of another network: MyPrivateNetwork, have been entered. The next step is to select Join. The network then appears in the Hamachi client, showing that you have joined it.
Leaving a Hamachi Network
Leaving a network created by someone else is done by right clicking on a network in the client, and selecting Leave network.
Deleting a Hamachi Network
If you wish to leave a network that you created the situation is significantly different. In this case, you are not leaving a network, but deleting it. Be careful with this option, as it will completely sever all connections between other members of that network and the action is irreversible.
It is done by right clicking on your network and selecting Delete network. Once you confirm the action, the network will disappear from your client and that of every other network peer.
When you are online on any network, your nickname is shown.
Click the preferences button and select the status tab. There will be a button to change your nickname, click it.
Enter a new username to change the nickname associated with your Hamachi account/IP. Changes will be propagated to your existing network peers within a few hours, and new peers will reflect your username change upon connection.