Unable to connect through RDP with less than 24 bit color depth

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Environment

SUSE Linux Enterprise Desktop 11 (SLED 11) or Server 11 (SLES 11)
Windows RDP Client
SLED/SLES rdesktop (RDP client)

Situation

Need to connect using the RDP protocol from a Windows RDP client or from a Linux system using a RDP client such as rdesktop.

When the connection is attempted output similar to the following is displayed:

connecting to sesman ip 127.0.0.1 port 3350
sesman connect ok
sending login info to sesman
login successful for display 10
started connecting
rdpx11 channel is not present
X11 RDP server started
Screen depth is not 24

Resolution

One option is to change the client to use 24 bit colors. For example, in the Windows client you can click on the "Options" button the click on the "Display" tab. You will see the setting for Colors. Just select "True Color (24 bit)" and it should work.

Changing the client to use 24 bit colors is the supported way to go. If you are in a situation where you must use a lower color depth due to bandwidth or some other reason there is another solution. It is unsupported but does seem to work fine.

As the root user edit the file /etc/xrdp/sesman.ini and look for the section that looks similar to this:

[Xdmx]
param1=-br
param2=-noreset
param3=-nolisten
param4=tcp
param5=--
param6=/usr/bin/Xfake

Add the following lines to change the resolution and color depth for the RDP server:

param7=-screen
param8=800x600x16

Restart the xrdp service by running (as the root user) "rcxrdp restart".

Now attempt to connect with the client set to 16 bit colors and it should work fine.

Additional Information

Consideration is being given to modifying the server to automatically allow a connection at a lower color depth. This may end up being an enhancement to a future release.

Disclaimer

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