View Full Version : [ubuntu] Got XDMCP working, no sound

December 26th, 2010, 01:18 AM
I have been working on setting up XDMCP on my ubuntu 10.10 media computer for too many hours. And so I thought to explain how to set it up and then ask two questions.

The first problem I encountered is that XDMCP is broken in ubuntu 10.04 and 10.10. However, it should be fixed in the upcoming release. To solve this, a different display manager needs to be installed. Instead of using GNOME's GDM I used KDM

sudo apt-get install KDM
During the installation a blue screen will appear with the question which display manager to choose. You guessed right, choose KDM.

After the installation two files need to be edited: kdmrc and Xaccess. Both are located in /etc/kde4/kdm

gksudo gedit /etc/kde4/kdm/kdmrc
find [Xdmcp] and add

Save and close gedit

gksudo gedit /etc/kde4/kdm/Xaccess
find the line

#* #any host can get a login window
and "*" (without quotes) below it
If you would like to add some safety, you can add the ip address of the client instead of "*".

I also opened the ports udp 177 and tcp 6000, because I use ufw. I don't know if it is needed if you don't use ufw. In case you want to try. Enable ufw:

sudo ufw enable
open port udp 177

sudo ufw allow 177
open port tcp 6000 for specific client ip address

sudo ufw allow proto tcp from 192.168.x.xxx to any port 6000

To access the "server" through XDMCP I logged out of the GUI of my Ubuntu client by the command:


I killed the running gdm

sudo stop gdm

And started the session by typing

X :2 -query 192.168.x.xxx
The ip address is that of the server.

I encountered a weird bug, that showed all the text on the screen mirrored and backwards. I solved the problem by turning of compiz. It might be a problem related to the proprietary NVIDIA drivers or it could be a compiz specific bug.

I hope this will be helpful to someone, as it has taken me quite a bit of time to figure out.

Now my two questions:
1. Is there an easy way to export the sound from the "server" to the client? I read some articles about esound, but that seems to be outdated. I also read that this must be possible with pulseaudio. Is there a guide on this?

2. I would like the client to login with XDMCP automatically. Is there a minimalistic Ubuntu (or Debian derivative) that automatically lets a user login?