It looks like there's a problem with the Veyon Server interacting with the internal VNC server (the failed to set socket timeout(0) message is also suspicious). Did you enable multi session mode in the Service settings? If so, can you disable it? Otherwise, try to enable it for testing. Can you alternatively install UltraVNC separately and configure the Veyon Service to use an external VNC server? Just to make sure it's not a problem with the builtin UltraVNC server.

I also wonder that the thumbnails do work and remote control isn't. Both functions use the same technique and settings for connecting to the computer. Is there any TCP connection limit configured client side?

Hello,

actually the Demo mode should work across subnets as long as long as computers can reach another via normal TCP/IP routing (NAT is not supported). Unlike other products, the demo mode in Veyon does not work with UDP broadcasts but TCP connections. When starting a demo on a computer in a different subnet, does it display the IP address of the teacher computer properly?

Restricting access to computers is possible through access control rules. These rules also allow you to e.g. restrict access to computers at the same location as the teacher computer. Other scenarios are possible depending on your environment and AD structure.

@tobydox Thank you very much.

I don't know if this helps ... but when I start "veyon-server" as a login-Script I get this message:
Screenshot_20210524_183807.png

@tobydox Thank you for this information! 😊 👍

Unfortunately there are limitations by the VNC protocol which could lead to the latencies you've described. Where do you observe the latencies? In the monitoring view with thumbnails or also while remote controlling/viewing a computer?

What's the output of systemctl status veyon? Maybe you need to enable the Veyon Service via systemctl enable veyon?

@studentloans999 Did you change the access group of the public key file to "Guest" or "Everyone" after importing? BTW the authentication test will only work on the master computer since it tests whether a private key file is readable and matches the public key file, so it's not an error if it "fails" on the client computers.

Hi,
There is a way, besides of Veyon which could meet easily your need, and give you ideas : BGinfo.
https://docs.microsoft.com/en-us/sysinternals/downloads/bginfo

This is a small exe launched automaticaly at each start up of a computer and stopped immédiately after :
function : create a desktop wallpaper with the information you may need, color wished etc...
Then you can have: user name, host, group, IP, MAC...
you can chose position and size of all this.
for me top right, about 1cm height characters (i can see them in real from my desk and from veyon also)
BGinfo.png
Good luck

Have you verified that the key pair IDs are identical on all computers? Did you set the access group for public and private key files properly? The public key file needs to be readable by everyone/guest on all computers while the private key file should be accessible by Veyon Master users on the teacher computers.

@fred

Ahhhhhh, very smart and so easy. Thank you!

Does the chromebooks have Linux (beta)? Or blocked by admins?

@itguy Thank you. will follow steps given and update

@drewloker said in 4.4.2 - Downgrade options? CRASHES Master and Clients, No Demo:

Demo still doesn't work.
I brought the whole lab up to 4.5.4.0
It went to Demo, showed my screen for a few second on a couple of the 7 students logged in a lab of 26 clients. Then, Demo stopped working even on the couple that did get my screen.
I was able to back out of Demo mode with out crashing their computer.

Hello
i have the same problem .. i opened a new topic: https://veyon.nodebb.com/topic/1258/veyon-4-5-4-vnc-serveur-crash-on-demo-mode
where I put the logs to see if tobydox manages to understand what is wrong ...
Fred

Yes it is laggy. I love to let my students play. They usually complain about lag. I have decided to test this. I told on of the students to keep there game open and leave. I opened the app it was laggy and the lag stopped when I closed it.

I do have quite the same experience with a number of 25 computers in wifi.
You can probably increase the response by having the master on RJ45 network cable if possible.