[Post-Install] Unable to RDP into Kubuntu KRDP from Windows 11

[robertsaron]

I was on Kubuntu 26.04 and thinking it was the problem, I forced an upgrade to 26.10, so I could get KDE 6.7. As there have been fixes and improvements for KRDP.
Computer one is on Windows 11 Pro. This will be called C1 in this post.
Computer two is on Kubuntu 26.10 This will be called C2 in this post.

C2 had Kubuntu installed, and the RDP from C1 to C2 worked, then for some reason, I formatted and reinstalled Kubuntu on C2, in an attempt to fix a different issue.
Now I cannot get RDP to work from C1 to C2. I can remote in Via SSH so I know the IP address works. The network connection is good.
No settings for RDP on C1 have been changed. Those have remained the same, minus what ever windows updates have come out in the past several months.

When RDP was working, I had a dedicated Nvidia 2060 installed, and have since removed it, and gone to on board graphics.
I just want this machine to be a media station, and VM server. But want a GUI installed. I do not want to walk over to it, every time I want to make a change to something that requires a GUI.
Does KRDP need a graphics card installed? Everything is enabled for KRDP, all the proper settings are in place.
RDP tries to connect, then just asks for the password again. I use bitvise which is based on Putty, and windows RDP.

The way bitvise works is you connect via SSH. Once connected, it has a RDP connection it can do over SSH. Kind of neat. I use that instead of Windows RDP, as Microshaft has made changes to Windows RDP that just do not work for the average user. Please let me know what logs and how to get them are needed.

[robertsaron]

So I formatted and Reinstalled and went with Kubuntu 26.04 LTS minimal installation. Still does not work.

[claydoh]

I will be booting into Windows later, as I can't recall issues using RDP to connect to my 26.04 box,. but not sure if I have done so from Windows in a long while. I can see what works or doesn't for me. I have had no issues from various Linux installs or my Android phone.

Is C2 on your local network? If so, is using bitvise necessary? Have you tried without using SSH? Having said that, I have used the option for this in KRDC from Linux systems (Another Kubuntu box, KDE neon, and KDE Linux) to my Kubuntu 26.04 box when connecting from outside and inside my home network.

[claydoh]

I had big troubles logging in from Windows.
However, I was able to do so after some digging, using Thincast, and turning off h264 encoding.



I could not get it working using the native Windows client, nor MobaXterm, these threw login errors.

I am sure it is the h264 part here, in combo with freerdp3 in *buntu for some on Linux as well.

Another option that might be helpful is to try krfb, and try logging in with a vnc viewer.



Note this is the exact same Wayland session, and connected using both RDP (thincast) and VNC (MobaXterm) at the same time lol.

I was going to go and connect from Kubuntu to Widows at the same time (using one of the remote connections to Kubuntu), but that would have been a bit weird. But I have done this before

[robertsaron]

Everything is local to my network.
I will try turning off h.264 and see if that works.

[robertsaron]

How do you turn off or remove h.264? I had some intel drivers installed so I installed these: sudo apt install intel-media-va-driver-non-free and it removed some other intel ones.
Still did not work.

[robertsaron]

I installed Kubuntu Studio. That is the one That I want stuff to work on. And still no go. KRDP hates me.

[robertsaron]

I now have ubuntu Studio installed, which uses KDE.

I have not installed any software onto Ubuntu Studio except for updates, KRDP and open SSH server.
When trying to connect to via RDP, It just keeps asking for my password again. And it never goes anywhere. No errors. Just the same password screen over and over.
If any logs are needed Let me know where to look, and I can provide for windows and Linux.

• SSH works fine.
• Router ports are open through should not be needed locally.
• UFW TCP and UDP are open for port 3389, though UFW is not enabled.
• I have a virtual Machine in Virtual box of Kubuntu on my windows machine. Installed KRDP, and tried to connect to it from my windows machine. Same result.
• I tried Remmina from my VM to C2, and that still failed.

It is like something is blocking it but I have no idea what it is. I can use Chrome remote desktop, but that is a pain due to some bugs as well. Unless google fixed them.

[claydoh]

How do you turn off or remove h.264? I had some intel drivers installed so I installed these: sudo apt install intel-media-va-driver-non-free and it removed some other intel ones.
Still did not work.

This is on the Windows side. Or rather the client side.

There is a group policy editor in Windows that is cumbersome and and doesn't offer more than disabling hardware acceleration in the Windows client. Which did not work, still having a login failure.

The third party Thincast remote desktop client application offers this as an option in is connection settings, which then connects successfully.

MobaXterm windows client does not appear to have a direct or obvious way to disable h264 . But does support VNC, so trying KRFB as an alternative to look at as an option. This was what I was using in 24.04

[robertsaron]

Hardware acceleration is disabled already on the windows. Will it do any good to disable it on the Linux side?

[robertsaron]

I looked into Thincast remote desktop client and could not figure out how to get it to wok. It wanted a server, and to set up web services. So I got rid of it.

[claydoh]

I just installed the client software
https://thincast.com/en/products/client



It is about as easy to use as KRDC (client) is on KDE.
Both KRDP/KRDC and Thincast use Freerdp, which may be why. Thincast is one of the main contributors to Freerdp.

Interestingly, on KRDC, I seem to have force h.264 enabled instead of "best available"



See my sig below for my PC specs. The Kubuntu machine has stock 7th gen I5 intel on-board graphics. The Windows box is the first PC. I have done nothing special on the Kubuntu box, other than installing the same intel driver as you have - It does media server duties (jellyfin and dvd ripping and encodiong).

[robertsaron]

I followed your link, and this what I see after downloading and installing.
I installed several pieces of their software and none of them looked like your screenshot.
I am happy to use different software if it works. But nothing is working.
I tried, freerdp, some from Github - which screwed up my SDDM so I had to reinstall the OS, lamco - which seems nice in a youtube video but setting it up is awful. Little to no documentation on how to do that.
There is just not allot of options, and all the good stuff is windows only or locked behind a paywall for linux. Or they do not work.

[robertsaron]

I finally found the right piece of software from them. I had to turn on H.264 in the thincast remote desktop client, and it worked. Weird. Makes me wonder if I need to turn that on for MS RDP software.
Thanks for the help.

[claydoh]

Odd that I needed to turn it off, while you needed to turn it on, in Windows, and connecting to the same server and distro

I did not see a way to turn it off in the MS client. But the Group Policy Editor has a LOT of options and subdirs to dive through.