xRDP session with xVNC is automatically closing the session if it used the port beyond 6000+

[BrivinTech]

xrdp version

0.10.2

Detailed xrdp version, build options

Paste the result between `~~~`.  Please DO NOT remove `~~~`!

Operating system & version

RHEL 8.10

Installation method

Doesn't matter

Which backend do you use?

XVnc

What desktop environment do you use?

GNOME

Environment xrdp running on

VM

What's your client?

rdesktop

Area(s) with issue?

No response

Steps to reproduce

I have set the below configuration in the sesman.ini,

X11DisplayOffset=90
MaxSessions=200
MaxSessions=200

i want to achieve more than 150 sessions in parallel. since i used the display offset as 90, the first session used (5900+90 = 5990) 5990 as the port, when i am continuously login more than 100 sessions in parallel, the xRDP sessions crossed 6000+ port ranges.. After few minutes, the xRDP sessions, which are using the port beyond 6000, automatically getting closed/disconnected. The sessions from 5990 to 5999 are staying stable without any disconnection.

Is there any limit on port to be used in the xRDP?
How to achieve 200+ parallel sessions?
Any other additional settings required?

The behavior is same, even if i used the port range from 5900..

✔️ Expected Behavior

200+ sessions should be opened in parallel.

❌ Actual Behavior

Sessions, which are using beyond 6000 ports, are getting disconnected.

Anything else?

No response

[matt335672]

Hi @BrivinTech,

Looking through the code for v0.10.2 on RHEL:-

1. your session X servers must be set -nolisten tcp. This is the default.
2. You have to use the Xorg backend, not the Xvnc backend. This is because of the way the socket connection works for the VNC server. It is also most likely the cause of your current problems.
3. Settings in /etc/xrdp/sesman.ini:-

X11DisplayOffset=90
MaxSessions=200
MaxDisplayNumber=290

To use the Xorg backend, install xorgxrdp, and uncomment the [Xorg] section in /etc/xrdp/xrdp.ini. I suggest you try this on a test system first.