One of the very frequent questions I get is about connecting two or more
machines, or even networks, across the internet. The most common scenario is
when traveling … you’re on the road, and you need to get at that one file
that you left at home or at work, on a different computer.
Enter “VPN”s, or Virtual Private Networks.
Become a Patron of Ask Leo! and go ad-free!
VPNs are exactly what the name implies: a virtual network of one or more
machines on top of a public network like the internet. When two machines join
the same VPN, it’s nearly as if they were next to each other. File and printer
sharing, as well as other applications such as remote desktop, work like they
would on a local area network – except the machines are separated, and
connected only over the internet.
I’ve talked about Hamachi before,
in my podcast. Now, after actively using it for several weeks, I’m recommending
it as a simple, quick, lightweight, and free VPN solution.
To use Hamachi, you download and
run a small client application from the Hamachi website. When this client runs,
it implements a virtual network adapter, and you’re given an additional IP
address that identifies you on any virtual network you join. You then create a
virtual a virtual network by name, assigning it a password. Now anyone running
the Hamachi client can join your network by connecting to it by name, and
supplying the password.
It really is that easy.
I now have the Hamachi client automatically starting on several machines, so
that regardless of where in the world I am, if I’m connected to the internet
those machines appear on my virtual local network.
As an example, I frequently print things on a printer at my wife’s business
from home. In the past that’s involved transferring the file to a mutually
accessible location on the internet, then using remote desktop to connect to
the remote computer, downloading the file, firing up the appropriate
application and finally hitting print in that application.
With both machines on the VPN, I simply print directly to the remote printer
at my wife’s business from the computer on my desk at home.
What I’ll call my acid test was a recent trip in my RV. The RV park has free
WiFi, so naturally I connect up and do a fair amount of work when I can. This
time, after booting up my laptop and connecting to the internet, I was
automatically connected to my machines at home and the machine at my
wife’s business. I was able to remote desktop to a machine at home, copy files
from a second machine there, and once again print directly to the business
machine. All transparently.
The VPN connection is encrypted for security. Aside from contacting the
Hamachi server initially, to locate the members of your VPN, all actual network
activity is directly peer-to-peer. In fact, if the Hamachi mediation server
goes down, you remain connected, and can continue to use your VPN without a
Hamachi works across NAT routers, even if there are NAT routers at both ends
of the connection. In nearly all cases it doesn’t require any reconfiguring of
the routers – no port-forwarding required. All machines running the Hamachi
client are simply and individually visible, even if they are all behind the
So far I’ve run into one drawback to Hamachi.
It does rely on that mediation server to establish network connections. That
means if the server is down, while existing networks and connections will
continue to work, new clients cannot join a VPN, and new VPNs cannot be
created. For example if you reboot while the mediation server is down, you’ll
not be able to reconnect to your VPN until it comes back up. Fortunately this
happens infrequently, and planned outages are announced in advance.
But for simple, inexpensive, and basic connectivity, Hamachi is working well for me, and I encourage you to give
it a try. I’ve played with Hamachi exclusively on Windows, but versions for OSX
and Linux are also available.