Today I was frustrated with not being able to make this work, but (like is often the case) a few minutes away from the problem brought on that Eureka! moment.
First, install QuickSynergy onto your Linux desktops:
shell# aptitude install quicksynergy
Install on Mac or Windows is probably simple enough, but I am not really sure. Linux, baby! Why would you spin your wheels any other way?
Start the QuickSynergy program on each machine. The machine you want to use for the mouse and keyboard is known as the "server", or the "Share" machine in the GUI. On that machine, enter the hostnames for each machine that you want to connect with:
In this case, I have my 'debianano' system (Debian Etch installed on a 4GB SD-card, booting on my EeePC) to the right of my main computer, so that is where I put its hostname. This is where I was hung up before — I kept using the client's IP Address (192.168.1.148 or whatever it was), which was failing. You need to use the hostname, which acts as a sort of guard to prevent connection to another machine on the network which may be using the IP address which you thought you were supposed to use. Click the [Start] button, and minimize the app or ignore it.
Then start the QuickSynergy application on the client machine (that which you want to use, but with a different mouse/keyboard -- laptops are the ideal candidate here). This would be my EeePC -- start the application and select the "Use" tab. Here, enter your server's IP address or hostname -- without a nameserver, though, your client may not be able to find the server, so I suggest using the IP address of your server (Shared) machine:
Click [Start] on the client machine(s), and go back to your main system (the Server, or Shared machine). Move your mouse to the edge (right edge in my setup) and the mouse should 'jump' off of the main screen and onto the client computer's screen. How cool, eh?
To get a hostname on your Linux machine, at a command prompt run 'hostname' all by itself. To get an IP Address, run 'ifconfig' (you may need root privileges, depending on the distribution which you're using). In the example below, I ran these two commands and have boldfaced the appropriate information which we need:
eth0 Link encap:Ethernet HWaddr 00:50:70:D6:2D:71inet addr:192.168.1.102 Bcast:192.168.1.255 Mask:255.255.255.0inet6 addr: fe80::250:70ff:fed6:2d71/64 Scope:LinkUP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1RX packets:2297486 errors:0 dropped:0 overruns:0 frame:0TX packets:1786329 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1000RX bytes:2437460921 (2.2 GB) TX bytes:421445533 (401.9 MB)Interrupt:20 Base address:0xe000
Both of these projects are actively maintained and developed, which is good news. Check them out at the Synergy2 and QuickSynergy project pages.
I hope this helps; if you're looking for good wireless networking for one of your devices, I really recommend this USB dongle!