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I am trying to set up a VNC connection from my PC (Ubuntu 18.04) to a headless (I can use only terminal) Raspberry Pi zero w (Rasbian 2020) using Remmina, but I am getting the error window:

Unknown authentication scheme from VNC server: 13, 5, 6, 130, 192

I have installed vnc in the raspberry and started it with vncserver :1. It gave me an IP-like thing. Then I have set a password with sudo vncpasswd -service and with vncpasswd -user using the same password. Then I tried to connect from the Ubuntu (PC) by using Remmina with the following credentials:

Server: [the IP-like address]
Repeater:

User name: [my_username]
User password: [server_or_user_password]

I tried both passwords, adding the line Authentication=VncAuth to the end of .vnc/config.d/vncserver-x11 and disabling encryption. In all cases, Reminna opens the error window and I can't connect.

Rohit Gupta
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Phineas
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7 Answers7

21

A bit neater write up on the same under the link below. Tested against default VNC server on Raspberry Pi 3 running Debian 11 (Bullseye).

https://docs.linuxconsulting.mn.it/notes/remmina-vnc-raspberry

====== Connect to Raspberry Pi OS via VNC using Remmina ======

-- //Tested with Raspberry Pi OS on July 2020// --

When trying to connect from your Linux machine using Remmina to a Raspberry Pi running Raspberry PI OS with RealVNC enabled you get the error

  Unknown authentication scheme from VNC server: 13, 5, 6, 130, 192

RealVNC only supports a few security schemes. Authentication=VncAuth seems to be the only scheme that allows direct connections from VNC-compatible Viewer projects from third parties. In order to change to VncAuth scheme in your Raspbian and set a password to accept connections from Remmina VNC plugin, open a SSH session (or a terminal window) on the Raspberry and generate your VNC password with:

sudo vncpasswd -service

Now, edit the file /root/.vnc/config.d/vncserver-x11

sudo nano /root/.vnc/config.d/vncserver-x11

and add the following line at the end of the file:

Authentication=VncAuth

Now your config file should look more or less like mine:

  _AnlLastConnTime=int64:0000000000000000
  _LastUpdateCheckSuccessTime=int64:01d65c12272dff1a
  _LastUpdateCheckTime=int64:01d65c12272dff1a
  Password=c3abbea3b003a0b231737c0541892d72
  Authentication=VncAuth

c3abbea3b003a0b231737c0541892d72 is the encrypted version of ''raspberry''; your line will be different.

Eventually, restart the VNC server service with

sudo systemctl restart vncserver-x11-serviced

and you are ready to connect to you Raspberry Pi using Remmina.

DarkDiamond
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user1681564
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10

I tried both passwords, adding the line Authentication=VncAuth to the end of .vnc/config.d/vncserver-x11 and disabling encryption

Modifying the .vnc/config.d/vncserver-x11 file changes how vncserver runs in service mode. These settings are ignored if you launch vncserver directly. Given that you're starting vncserver as follows

I have installed vnc in the raspberry and started it with vncserver :1

it means that the authentication method for that vncserver instance will not be using Authentication=VncAuth but instead the default (which Remmina doesn't understand).

To resolve this problem, start vnc server as follows:

$ vncserver -Authentication VncAuth :1

Note that these arguments are case sensitive (and doesn't always give useful error message if you get it wrong).

Dodgyrabbit
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8

I know this is an indirect solution for the above error. This will install Real VNC Viewer and use this to create a working VNC connection out of the box. However now Real VNC requires for an account so it is not so much of a solution anymore...

Download the Real VNC Viewer from here. After installing and starting the program, I had to put the Domain (The raspberry IP and not the "IP-like thing"), the username and the user password.

The installation was done on the command line using:

wget https://www.realvnc.com/download/file/viewer.files/VNC-Viewer-6.20.529-Linux-x64.deb
sudo dpkg -i VNC-Viewer-6.20.529-Linux-x64.deb

Tested on Ubuntu 18.04.

Phineas
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1

As all of these hints did not work for me, i was investigating by try and error. Maybe someone finds my solution helpfull.

I went to the gui settings of realvnc-Server (click right on Vnc-logo in the upper task-bar) and choose "options".

I switched temporary to "Interactive UNIX-Authentication". I was informed, that the PW would be deleted. Tried connection on remmina: Failed.

But after switching back to VNC-PW: As I set the VNC-PW via gui again, i choosed the option "allow old PW sheme" (or something like that).

New try with remmina: That did it! :)

virtualme
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1

My final solution was also not to use Remmina. I used TigerVNC from Linux Mint and it just worked, after hours of trying to make Remmina work (which works fine for other Linux and Windows vnc servers).

Bruce
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0

None of these worked for me. My solution was to simply use RealVNC Viewer instead of Remmina. If my understanding is correct Remmina does not support proper authentication schemes to connect to RaspberryPI.

user568021
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0

The later versions of VNCServer will need further tweaks to get it to work with Remmina.

My config is now: (/root/.vnc/config.d/vncserver-x11)

Authentication=VncAuth
Encryption=PreferOff
Password=c3abbea3b003a0b231737c0541892d72
SecurityTypes=<auto>
UserPasswdVerifier=VncAuth

This was achieved by using the GUI and when selecting a password for the VNC user I checked the "allow connections from legacy clients". Obviously there's a little bit of an update issue between Remmina/RealVNC.

I'm guessing RealVNC don't recommend doing this. However this will get you up and running in the short term.

PeterS
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