As security administrators, we
often find ourselves installing
multiple OS platforms just to be able to use particular tools. For
example, UNIX provides a few best-of-breed security tools not available
on Windows, and Windows hosts
wide-ranging business tools in Microsoft Office not available on native
Linux. You can find many solutions
that let you take software based on
one platform and run it on a different
platform. For example, emulation
products such as Cygwin (a Windows-based environment for running particular Linux applications) or virtual
machine (VM) software such as
VMware Server or Microsoft Virtual
Server let you essentially build multiple separate computers on one physical host. Sometimes, however, you
want the speed, compatibility, or
redundancy of running various platforms on physically separate computers. In this situation, a useful tool
called Synergy can help you control
multiple computers and monitors
from a single keyboard and mouse.
How Synergy Works
A traditional KVM switch requires a
keystroke or activation of a physical
switch to shift keyboard and mouse
input and video from one computer
to another. Similar in concept, the
Synergy software lets you share a keyboard and mouse among two or more
computer systems and monitors.
However, Synergy requires that each
computer be connected to its own
monitor. What this means is that you
can place your Windows laptop beside
the monitor connected to your Linux
or Macintosh (or another Windows)
computer, start the Synergy software,
and control both systems with just
one keyboard and mouse. You simply
drag your mouse from one monitor to
the other and the keyboard input
switches to the other computer. This
setup can be very efficient for security
administrators who run predominately UNIX systems but also need to
keep an eye on Microsoft Outlook
running on a Windows system or perform Windows administrative tasks.
Synergy is a client/server tool that
basically works like this: The computer whose keyboard and mouse
you’ll use acts as the primary computer, or server. Synergy uses the
TCP/IP network to send the keyboard/mouse commands entered at
that primary computer to the secondary computer, or client.
Synergy does a remarkable job of
capturing the keyboard and mouse
input—sometimes you even forget
that you’re using multiple platforms.
You can share clipboards between
your server and client, and even
across different platforms. For example, you could copy text from Safari on
a Mac and paste it into an Outlook
email message on a Windows
machine. Let’s walk through how to
download and install Synergy on the
client and server, edit a configuration
file, and start the service.
Installing Synergy
Download Synergy at http://synergy2.sourceforge.net. The latest version
(1.3.1), runs on Windows 95 and later,
Mac OS X 10.2 and later, and most versions of UNIX that run X Window version 11 revision 4 or later. Extract the
latest version of Synergy to each of the
systems you wish to control. On the
Windows platform, run the program
SynergyInstaller-1.3.1.exe to install the
application. On UNIX systems, you’ll
edit a configuration file contained in
the extracted Synergy package.
Although Synergy works as a
client/server application, you actually
install the same package on each
computer. The computer with the
keyboard and mouse physically connected will be your server and all
other systems will be clients. (Synergy
refers to the server and client computers as “screens.”) Next, we’ll define
the physical relationships between
these screens.
Configuring a Windows Server
After you’ve installed Synergy on each computer that you wish to control,
you need to configure it. I’ll first
describe how to configure Synergy for
a Windows server screen, then for a
UNIX server screen, and finally for
client screens.
On a Windows-based server, click
Start, All Programs, Synergy to launch
the Synergy program. Click Share this
computer’s keyboard and mouse
(server). Next, in the Screens & Links
dialog box, click Configure and add
each of the computers, or screens, you
wish to share. At a minimum, you
must use two screens—the server and
a client—but you can add multiple
clients if you physically have the computers. Click the plus (+) button and
enter your server computer’s host
name in the Screen Name text field.
Click the + button again and enter the
host name of the computer that you
want to share the server’s keyboard
and mouse—this will be your client.
As aliases, you can enter alternate
names of the computers; for example,
you could enter the NetBIOS name as
the screen name and then enter the
fully qualified domain name (FQDN)
of the computer, or even an IP
address, as an alias.
Next, specify the physical relationship, or link, between the computers.
The configuration fields for links might
be confusing at first. Think about how
your computer monitor screens are
placed in relation to each other, not
from your point of view as you face the
computers. If your server computer is
physically situated to your client computer’s right, you would configure the
relationship like this:
0 to 100% of the left of
serverMachine goes to
0 to 100% of clientMachine
then click Links + to add the link. This
configuration means that if you drag
your mouse across any portion (0 to
100 percent) of the left edge of the
server’s screen, Synergy will transfer
keyboard and mouse control to the client computer.
It’s important that you also define
a reciprocal link to return the mouse
and keyboard control to the server.
Enter
0 to 100% of the right of
clientMachine goes to
0 to 100% of serverMachine
and click Links + to add the reciprocal
link.