RDP (GNOME) encryption error in Ubuntu 24.10 vm

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s1l3nce

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Jan 19, 2024
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I'm having a very weird issue when connecting to an Ubuntu VM inside Proxmox through RDP. Let me describe the different scenarios:

1. If I connect from a Windows PC (physical computer) to the Ubuntu VM inside Proxmox, I often get an encryption error and my Windows machine gets disconnected. A good way to replicate the issue fast is to stream video content while connected on a RDP session.
2. If I connect from a virtual machine (Windows or Linux, doesn't matter) to the Ubuntu VM, I don't get the encryption error.

3. If I connect from a Windows PC (physical computer) to an Ubuntu installed on a virtualbox VM, I don't get the encryption error either.

In the following video, you can see a comparison of the 1st and the 3rd scenario. On the left, I'm connected to an Ubuntu vm inside proxmox and on the right I'm connected to a vm inside virtualbox.

I found a post in askubuntu that explains the same issue I'm having.

I don't know if this is a Proxmox issue, an Ubuntu issue or an RDP issue but I thought this might be a good place to share it.

BTW, on a different note, I've noticed that my graphical performance is a bit better when connecting with RDP to the virtualbox ubuntu vm than to the proxmox ubuntu vm. It's quite noticeable when moving windows around. Why is that? Shouldn't it be the other way around? I have allocated the same amount of resources to both vms (2 CPUs and 8 gigs of RAM.
 
Just to see if it might be an issue with certain modifications I did while trying to passthrough my Intel iGPU, I did a complete reinstallation (using XFS this time instead of ZFS) and I still have the same exact problem.
 
One more thing: I don't know if this is normal but CPU usage in Ubuntu while connected through RDP (Gnome) is quite high. SPICE CPU usage is considerable lower. On the other hand, when connecting to a Windows VM, CPU usage from Spice and RDP are very similar.

I've also observed that in both cases, RDP is sending a lot more data constantly, both in Ubuntu and Windows. So SPICE is a lot more efficient than RDP, based on my testing results. I just find it very inconvenient having to download *.vv files from Proxmox every time I have to start a SPICE session.
 
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s1l3nce said:
I'm having a very weird issue when connecting to an Ubuntu VM inside Proxmox through RDP. Let me describe the different scenarios:

1. If I connect from a Windows PC (physical computer) to the Ubuntu VM inside Proxmox, I often get an encryption error and my Windows machine gets disconnected. A good way to replicate the issue fast is to stream video content while connected on a RDP session.
2. If I connect from a virtual machine (Windows or Linux, doesn't matter) to the Ubuntu VM, I don't get the encryption error.

3. If I connect from a Windows PC (physical computer) to an Ubuntu installed on a virtualbox VM, I don't get the encryption error either.

In the following video, you can see a comparison of the 1st and the 3rd scenario. On the left, I'm connected to an Ubuntu vm inside proxmox and on the right I'm connected to a vm inside virtualbox.

I found a post in askubuntu that explains the same issue I'm having.

I don't know if this is a Proxmox issue, an Ubuntu issue or an RDP issue but I thought this might be a good place to share it.

BTW, on a different note, I've noticed that my graphical performance is a bit better when connecting with RDP to the virtualbox ubuntu vm than to the proxmox ubuntu vm. It's quite noticeable when moving windows around. Why is that? Shouldn't it be the other way around? I have allocated the same amount of resources to both vms (2 CPUs and 8 gigs of RAM.
Click to expand...
Registered an account to let you know I had the same issue. Disabling the firewall on network adapter seems to have made it happen much less frequently*

The firewall did not have any effect. After lots of searching, I finally identified the issue and *think* so far the fix has worked.

To see if you are having the same issue, you can run open up the Proxmox shell and run:

#journalctl -xe

I was seeing these types of events:

Code: 
Jan 31 09:04:54 local kernel: e1000e 0000:00:19.0 eno1: Detected Hardware Unit Hang:
                                TDH                  <24>
                                TDT                  <5c>


That gave me more definite search terms which led me to https://forum.proxmox.com/threads/e1000e-eno1-detected-hardware-unit-hang.59928/post-378352

It is a long thread, and there are some other commands in there , but the one that helped me was:

ethtool -K eth0 tx off rx off

I no longer see the hardware unit hang events in journalctl after running that, and my RDP sessions stay connected
 
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Thank you very much! I'm not using Ubuntu at the moment but I will try it next time I do
 
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