By Joseph Moran

Most people know that a virtual private network (VPN), allows them to securely link computers using an ordinary Internet connection. The catch is that VPNs can be notoriously difficult to configure and get working properly, especially through broadband routers.

But a free software utility called Hamachi (which you can download at https://secure.logmein.com/products/hamachi/vpn.asp) will in most cases let you set up a working VPN in just a few minutes, usually with little or no configuration. For purposes of this column, we used Hamachi to set up a secure link between two Windows Vista systems in New York and Florida. The software is also compatible with XP and 2000, and there are OS X and Linux versions, too.

Hamachi provides VPN connections in a peer-to-peer fashion, operating much like IM software. Although Hamachi uses its own servers to locate users and establish links between them, any data transferred is directly between connected computers.

When you install Hamachi, you’ll have the option to use either the Free or Premium version (more on the differences between the two in a moment). For now, it doesn’t matter which one you choose, and you can try the Premium for 30 days before it will revert back to Free mode.

The Hamachi install wizard will also give you the option to Disable access to Windows File Sharing and other services vulnerable to malware. Of course, file sharing may be precisely the reason you’re setting up Hamachi in the first place, so if you leave file sharing enabled, be sure you know and trust anyone you invite to join your network.

Creating a VPN

After Hamachi is installed and launched, click the “power” button in the lower left corner to activate the software. The button will turn green, and you’ll be prompted to create a Hamachi account for your computer and choose a Nickname Hamachi servers will use to identify it.

To set up a network, click the Network button (the triangle) to the right of the power button and select Create a new network. In the top space, type in a name for your network; it can be anything you want it to be so long as it is less than 64 characters, including spaces.

Below that, specify a password that will grant others access to your network. As is always the case, avoid using the short and easy-to-guess kind password because that and the name are all anyone will need to join your network. (Hamachi doesn’t impose a minimum password length.)

After your password is entered, Hamachi’s servers will issue your computer an IP address. This address, which is displayed at the top of the window, is used only by Hamachi’s virtual network adapter for Hamachi connections; it is completely separate from the IP address your computer’s physical network adapter uses.

Joining Your VPN

When you see your new network listed next to a green dot, it’s up and running and ready to receive connections. You can now distribute your Hamachi network name and password to anyone you want to join it. How you do that is up to you, but remember e-mail is an unsecure form of communication that can be inadvertently be delivered to the wrong person. If you do send network information via e-mail, consider omitting key details (like what the name and password are for) and provide the missing information by phone.

To link to your network, another party will need to download and install the Hamachi software just as described above. They will choose to Join an existing network and then enter the name and password you provided. When someone joins your network, you should see their computer and Hamachi address listed in your Hamachi window, and vice versa.

A green star indicator next to an entry should denote a good connection, but each party to the connection should test connectivity by right-clicking the other’s entry and selecting Ping. If you get responses, all is well, and you can close the window. If not, your computer’s firewall may be blocking traffic across the Hamachi connection. Disabling the firewall temporarily will verify this. If it turns out to be the case, check out logmeinwiki.com/wiki/Category:Firewall, which provides tips configuring various third-party firewalls to work with Hamachi.

Right-clicking on a member of your network will not only let you ping them, but it will also conduct a text chat or browse any shared folders available on that computer, assuming you left Windows file sharing enabled during setup. If you didn’t, click the gear button, choose Preferences, select Security, and clear the box labeled Block vulnerable Microsoft Windows services. You’ll find various other configurable options here as well.

Hamachi VPNs aren’t just limited to a single network with two members. You can create up to 64 networks with as many as 16 members apiece. Incidentally, when you want to disconnect from a Hamachi connection, right-click the network name and select Go Offline; another right click will let you jump right back on.

Once Hamachi is up and running, you can use it for anything from sharing files and folders or application data (like iTunes) to online gaming and more. At logmeinwiki.com/wiki/Image:Hamachi_logo.gif, you’ll find info on how to set up various applications and scenarios across a Hamachi connection.

Last but not least, everything we’ve described here can be done with the free version of Hamachi. But if you decide to register the premium version of Hamachi (for $39.95 a year), you’ll get some added features like support for more and larger networks, and more control over your network, like the ability to block any new members or create a list of banned computers.

Joseph Moran is a regular contributor to PracticallyNetworked.