Share your mouse and keyboard between multiple computers on your desk

[Snowhog]

I picked up my Toshiba laptop from the repair shop today (replaced the LCD). I was talking to the tech about my playing around with 'sharing' my two laptops using KRDC and Krfb, and VNC. He asked if I knew about Synergy. "No", I said, and he pulled it up on the monitor.

I have installed it on both PCs (synergy and quicksynergy, the GUI configuration front-end, are available in the standard repos). My HP is running Kubuntu 12.04; the Toshiba, PC-BSD 9.0. I'm using the HP as the synergy server and the Toshiba is the client. This allows me to use my HP's keyboard and connected mouse to access and control my Toshiba! Way cool!:cool: The mouse just moves seamlessly between the two screens. Once the mouse pointer is on the other PC, my HP keyboard and mouse affect the Toshiba. Cool, cool, cool.

[oshunluvr]

WOW, cool find. I might even install a desktop on my server!

[Snowhog]

QuickSynergy and Synergy need to be installed on the host PC and up to four client PCs.

On the host PC -- the one that you want to use to control the other PCs -- launch QuickSynergy. On the 'Share' tab, type the hostname of up to four PCs to be controlled in each of the four boxes (Top, Right, Bottom, Left), which represent the host PCs screen edge that will access that client PC. Stay on the 'Share' tab and click on Execute. This enables the Synergy Server.

On the client PCs, launch QuickSynergy. Click on the 'Use' tab and type in the host PCs IP address. Stay on the 'Use' tab and click on Execute. Done.

Now, on the host PC, move your mouse cursor to the edge of the screen representing the client PC you want to control. You should see your mouse cursor appear on the screen of that PC. Control away.

[HalationEffect]

I heard about Synergy over at Ars Technica, where the site staff appear to be quite enamoured of it... and laptop hammocks.



IIRC, some of the staff use Synergy so that they can still use the laptop even while it is in a hammock.

[Snowhog]

I'd be a bit surprised at that. The 'controlled' PC has to be 'seen' by the user -- it's display doesn't appear on the host PCs desktop.

[HalationEffect]

I'd be a bit surprised at that. The 'controlled' PC has to be 'seen' by the user -- it's display doesn't appear on the host PCs desktop.

I neglected to mention that the laptop in the hammock does need to be connected to an external monitor.

[Snowhog]

That would do it.

[HalationEffect]

I tacked on the sentence after the pic in a hurry, as I realised that laptop hammocks seemed to be completely from left-field in the post as it was before the edit... it wasn't at all clear why they had any connection with the topic of this thread.

I just loved the combination of a very cheap DIY project (apparently a laptop hammock can be made for as little as one dollar), and a very cool software project.

It appealed to my whimsical nature even more when it occurred to me that the laptop hammock was an example of synergy with Synergy

[GreyGeek]

That IS cool!

My LAN IP addresses are dynamic, starting at *.100 to *.105. Right now I am *.104 and no one else is connected to the wifi. Tomorrow I could be another number in the range. This will make setting up Synergy impossible unless I lock IP addresses to MAC addresses.

It would be neat the next time my wife asks me to help her out of a problem to merely touch the upper left corner of my screen and then take control of her computer without leaving my recliner. But, I'd have to disable my screen effects.

[oshunluvr]

GG: The readme file say you can use the DNS name of the server rather than the IP. Doesn't that mean if your hostnames are configured correctly you're good to go?

[GreyGeek]

Don't think so. Hostnames are configured automatically by Upstart. /etc/hostname contains only the host name, with no reference to an IP address. /etc/hosts contains
127.0.0.1 localhost
127.0.1.1 jerry-Aspire-V3-771
and some other IPv6 stuff.

The default DNS address of a box connected to a wireless router is typically 192.168.1.255

If one could guarantee a specific IP address by either using a wired network configured to give a fixed IP or by assigning IP addresses to specific MAC addresses in the wireless router configuration setup then Synergy will probably work.

[Snowhog]

But I 'think' you are speaking in terms of 'preconfiguring' the Synergy setup on the client PC. That isn't a consideration if you understand/accept that the IP address on the client must be configured 'before' you execute it.

[oshunluvr]

I would look at the results of

nmap -sP 192.168.1.0/24

This should show the name and IP of everything on your network. The names shouldn't change even if the IP does as long as all the machines are configured with hostnames. Here's part of my output

Nmap scan report for Mini110.home (192.168.1.16)
Host is up (0.00080s latency).

Mini110 is the hostname of my netbook and is not configured with a fixed IP.

From the Synergy Users Guide:

You can find out the client name that Synergy will use by opening the About dialog on the
client – look for the "Hostname". This is the name that your computer calls itself.
Once you have entered the client name, click "OK" to return to the grid. Repeat this process
for each client you wish to add. Once you have added all clients, click "OK" to return to the
main window.
Now you need to apply the configuration. If you selected "Service" in the wizard, then click
"Apply". This will restart any running process and apply the new configuration. Otherwise, if
you are using "Desktop" mode, then you will need to click "Start" (or if the process is already
running, click "Stop" before configuring, then "Start" after you’re done).
3.3 Configure a client
Once you’ve configured your server, you need to connect each client to the server. Assuming
you selected "Client" during the wizard, the Client option should be checked on the main
window. In the "Name of the server" textbox, enter either the IP address (e.g. 192.168.0.6)
or the DNS name of the server if you have DNS configured on your local network (many
users do not).

[GreyGeek]

I would look at the results of

nmap -sP 192.168.1.0/24

This should show the name and IP of everything on your network. The names shouldn't change even if the IP does as long as all the machines are configured with hostnames. Here's part of my output

Nmap scan report for Mini110.home (192.168.1.16)
Host is up (0.00080s latency).

Mini110 is the hostname of my netbook and is not configured with a fixed IP.

From the Synergy Users Guide:

I was aware of the nmap command and ran it yesterday:

nmap -sP 192.168.1.0/24


Starting Nmap 5.21 ( http://nmap.org ) at 2012-08-22 14:25 CDT
Nmap scan report for 192.168.1.1
Host is up (0.0053s latency).
Nmap scan report for 192.168.1.100
Host is up (0.00017s latency).
Nmap scan report for 192.168.1.101
Host is up (0.017s latency).
Nmap done: 256 IP addresses (3 hosts up) scanned in 9.07 seconds

A little while ago I reconfigured my wireless router to give a fixed IP according to the MAC, so that I would always be *.100 and my wife would be *.101. Of course, I had to set the DNS servers manually as well. However, my idea doesn't seem to work. nmap gives the same output (except for IP addresses) after my reconfiguration as before. Just to be sure I tried a couple ping commands, which don't work as fast as nmap:

or ip in $(seq 1 254); do ping -c 1 192.168.1.$ip>/dev/null; [ $? -eq 0 ] && echo "192.168.1.$ip UP" || : ; done


for ip in $(perl -e '$,="\n"; print 1 .. 254;') ; do ping -t 1 -c 1 192.168.1.$ip>/dev/null; [ $? -eq 0 ] && echo "192.168.1.$ip UP" || : ; done

My hostname was setup automatically during my install and I haven't messed with it. So, there is something different between our two internet access configurations.

As it sets now, access to my wireless router would be denied to anyone but our two machines. I am going to reverse my changes and play with Synergy awhile.

[GreyGeek]

I reconfigured back to my old wireless config, letting dhcp hand out what it wants. Then I ran Quick Synergy on both mine and my wife's machine. Neither could see each other.

EDIT:

I futzed around a while and got it to see my own screen, for all the good that does. BUT, I also got it to work with my wife's netbook, but ONLY the keyboard and mouse. If I can't see her screen I can't see where I am pointing or what I am typing. IOW, only the keyboard and mouse work. I did some digging and discovered that the documentation that oceanluver posted was for the Windows version. I downloaded the pdf documentation and found that it documents ONLY the Windows GUI. The Linux GUI, QuickSynergy, by comparison, is ... trash.

First, the Linux QuickSynergy does not have a client and server section. It has only three tabs: Share, Use, Settings. There is a synergys and a synergyc CLI app, but synergyc is buggy.

How I got it to partially work:
On my computer, the "Server":
On the Share tab I entered the hostname of my wife's netbook, "june-A0521" in the bottom box.
On the "Use" tab is a text box for entering "Server hostname/IP address" and one for the "Screen Name". I entered MY IP address (which could change if I don't use a MAC wireless config to fix it): 192.168.1.104. But, it did not matter what I put for my screen name, or if I left it blank.
On the "Settings" tab is a textbox pointing to "Synergies binaries path". It defaults to /usr/bin.

On my wife's netbook, the "Client":
I didn't put anything on the share tab.
On the "Use" tab I entered MY IP address (192.168.1.104) in the "Server hostname/IPaddress" textbox and I put HER hostname, "june-A0521" in the "Screen name" textbox.
The settings tab was defaulted to the same as mine.

BUT, it really didn't matter what I put into the "Screen name" on June's box OR my box. All that mattered is that what I put as her screen name in her "Use"-"Screen name" should also be put in a box on MY "Share" tab. I chose the bottom box on my setup.

Now, as to the problem of why my display doesn't switch to her screen...
http://synergy-foss.org/wiki/Startup

/etc/gdm/Init/Default:# This script needs to start synergyc as user root - this synergyc runs on the# login screen. IMPORTANT: I've found that at boot time NAME LOOKUP does not# YET work so you MUST use the server's IP ADDRESS otherwise synergyc will# fail to connect and exit after a few seconds (--reconnect does not work):# so the BUG REPORT/enhancement request would be to make --reconnect work so# that it never/ever exits synergyc - even if name lookup does not work, [COLOR=#ff0000]or# if there is no display[/COLOR], etc.. As a (bad) alternative you can also use: # (sleep 10; /usr/bin/synergyc YOUR_SERVER_HOSTNAME) &# NOTE: I've also found that sometimes you need to kill synergyc with -9/usr/bin/killall -9 synergyc sleep 1 /usr/bin/synergyc YOUR_SERVER_IP/etc/gdm/PostLogin/Default:# this script needs to kill the root synergyc started by Init/Default/usr/bin/killall synergyc sleep 1 /etc/gdm/Xsession:# this script will start the user synergyc - the one that runs after you have logged in # Note: here you can also use your server's hostname, instead of the IP/usr/bin/killall synergyc # no need, I guess?sleep 1 /usr/bin/synergyc YOUR_SERVER_IP

Apparently it works fine on and between Windows boxes. Not so much on or between Linux boxes.

I do not have a local DNS server running (which is the default setup), and don't plan to add one. So, I guess I continue to use the "sneaker net" (her sneakers!) to get her out jams.