Remote access to your office desktop under Linux

Tags: Faq Linuxtips

Remote wake

If your work machine is configured to suspend when not in use, you may need to wake it before you can connect to it. If your machine is on the Computer Science network, you should visit wol.dcs.aber.ac.uk to wake it. If your machines on an IS network (most Physics/Maths machines) you should visit myaccount.aber.ac.uk/protected/paws to wake it.

SSH access

Our standard Mint desktop build includes an ssh server. If you have a working VPN connection, you should be able to ssh into your machine.

Remote access to a running session

If you are currently logged in on the console and you want to connect to that already-running session from home, I’d recommend that you use VNC.

Install VNCViewer on your home machine.
Install x11vnc on your work machine.
Login to your work machine via ssh and run: x11vnc -display :0
If your home machine is Linux, you can then connect to your work machine using: vncviewer -via your-work-machine.dcs.aber.ac.uk :0
If your home machine is Windows, you will need to set up an ssh tunnel using Putty, tunnelling local port 5900 to port 5900 on your work machine. You should then be able to connect VNCViewer to localhost:0

N.B. When connected to a running session like this, anything you do will be visible on the physical screen that’s attached to your PC in your office. This could represent a security risk, especially in open plan offices.

Remote access to a new session

This takes a bit more setting up, but has the advantage that you do not need to be logged in at work. You can also tailor the remote session resolution to the size of the screen you use at home.

I’ve tried four approaches.

VNC session launched directly from lightdm

This gives you a login screen that you can connect to using vncviewer (as above). When you log in, you get a normal desktop session. When you disconnect, the session gets logged out. To enable this:

On your work machine, apt-get install tigervnc-standalone-server and edit /etc/lightdm/lightdm.conf to include the following lines:

[VNCServer]
enabled=true
port=5900
command=/usr/bin/Xvnc -SecurityTypes None
width=1280
height=1024
depth=24

You can change the “width=” and “height=” lines as you prefer. Restart lightdm: systemctl restart lightdm

You should now be able to connect VNCViewer to display :0 on your work PC (see the section above for more details).

The disadvantage of this approach is that you will be logged out if you disconnect from the session. I imagine most people won’t like that.

VNC session launched from xinetd

This gives you a login screen that you can connect to using vncviewer (as above). When you log in, you get a normal desktop session. When you disconnect, the session persists. N.B. This option should never be exposed directly to the network - since the session persists and is not password protected, if you expose it to the network, anyone can take over your desktop. Tunnelling via SSH should be safe (assuming no other people have shell accounts on your machine).

On your work machine, apt-get install xinetd tigervnc-standalone-server and edit /etc/lightdm/lightdm.conf to include the following lines:

[XDMCPServer]
enabled=true
port=177
listen-address=localhost

Create /etc/xinetd.d/Xvnc with the following content:

service xvnc_1
{
    type = UNLISTED
    disable = no
    protocol = tcp
    socket_type = stream
    bind = 127.0.0.1
    port = 5900
    wait = yes
    user = root
    server = /usr/bin/Xvnc
    server_args = :1 -inetd -query localhost -geometry 1600x1200 -depth 24 -once -fp /usr/share/fonts/X11/misc -DisconnectClients=0 -NeverShared -SecurityTypes None
}

You can change the “-geometry” option to use a different resolution if you prefer.

Now restart xinetd and lightdm: systemctl restart xinetd lightdm

You should now be able to connect VNCViewer to display :0 on your work PC (see the section above for more details).

Windows remote desktop

This one could be the nicest option:

No need for extra software under Windows at home.
Session resume is built in.
No extra configuration required.

However, I found it very unreliable at the client side - both rdesktop and xfreerdp randomly crashed when talking to the server. After a bit of testing, I decided it just wasn’t stable enough. Your mileage my vary!

Just install xrdp: apt-get install xrdp

You should then (via VPN) be able to connect to your PC using remote desktop software. The first time you connect, you’ll get a login screen. If you reconnect to a session, it’ll work. The desktop can be resized (or, at least, it will start to match the size of your remote desktop window).

Xpra

Xpra takes a very different approach: Tunnelling individual windows.

I’m not going to go into it in detail because, while it does its job very well, I don’t think most people are going to find it particularly useful for home working. This is just a placeholder to point out the option, should anyone be looking for it.