David Szpunar: Lead Engineer, PC Help Services

David's Church Information Technology

November 9th, 2007 at 5:44 pm Print This Post Print This Post

Synergy Keyboard and Mouse Sharing App

A few weeks ago, I ran into a post (I think it was from Matt Cutts but if I saw it somewhere else, I apologize for the lack of credit) that talked about a little tool called Synergy. It hasn’t been updated since last year, but it seems to work well enough for its purpose: two computers, one keyboard and mouse, connected via network. It’s a bit arcane to set up (and I’ve just used the Windows version, there are Linux and Mac options available), but it works as advertised. Here’s a quick overview, but the Matt Cutts post and the documentation on the Synergy website provide plenty of help:

  1. The computer whose mouse and keyboard you want to use is the server. Install Synergy and configure the Server options, and enter Test mode (make sure to use the computer’s network name when creating “screens,” or create a pretty name with an alias that is the network name).
  2. Configure the positioning of how each computer’s screen is related to the other (you have to create the link in both directions).
  3. Click Start once you’ve finished with Test mode and it works.
  4.  The computer you want to control with the server’s keyboard and mouse is the Client. Install Synergy on this computer, too.
  5. Enter the network name of the server you already set up, and click Start. Use Test mode to see if it will connect without errors; you can then try it out to see if it works (if the server is running).
  6. Click Start once you’ve finished with test mode and it works.
  7. Have loads of fun!

I set this up at work, with my desktop as the server and my laptop as the client. Ta-da, now I can use my nicer mouse and Natural keyboard on my laptop, just by moving the cursor off the desktop’s screen! This is really slick.

What is it missing? Security, for one. There is no authentication between the client and server. So someone else running this software on your network could connect depending on how your computer is configured. I assume the traffic can be sniffed and interpreted, if someone were so inclined (but this would likely be difficult, on a switched LAN, and with the need to decipher mouse and keyboard controls). I imagine the keyboard would be much more useful to sniff than the mouse, which would be almost useless. On a home network, this probably isn’t an issue. At work, it depends on your co-workers: if they’re probably never heard of this software and you’re the only IT guy, it is very unlikely they would even know to look for such a thing! One way to slightly increase security would be to use a non-standard port. The default is 24800, but if you change this on the Advanced button, someone running the same software would have to do more work to figure out how to connect (don’t forget to set the same port on client and server!).

The other thing that’s missing is a polished interface. There is a GUI for Windows, but you should probably read the Using Synergy guide on their site the first time through when defining Screens and Links (positions relative to each other). Mac and Linux appear to be configured via text file only, but they do have the steps listed on their site. I haven’t tested this, but it does sound exciting to use a Windows computer’s keyboard and mouse to control a Mac or Linux machine right next to it! Or any of the other directions you could go.

With those caveats, if you have the two computers in close proximity you need to test this, I highly recommend going geek crazy and testing this. Just be sure to keep the computer equipment out from under your chin; it doesn’t generally take kindly to liquids, including drool!