Nettle SSH and raspi-config

Yesterday, while putting the finishing touches to the Setup of a new headless Raspberry pi 4 I found myself in a maze of dark twisty passages.
The Pi setup was complete, with Raspberry Pi Os, Bullseye, and SSH and VNC server enabled.
Using Avalanche to VNC I worked through raspi-config to see if anything else needed changing and spotted:
>Display Options > D3 Pixel Doubling
Oh! that must be what RComp calls “Big mode” I thought and, unwisely as it turned out enabled it, exited configure and rebooted.
Avalanche was able to connect to the pi but the screen was black. This did not seem to be much of a problem at first as it should have been possible to SSH into the pi and use sudo raspi-config to turn off the pixel doubling.
But not so fast. SSH from the mac flatly refused to talk to the pi on the spurious grounds that it had seen the pi before with a different sd card and hence different key.
OK, here I get to the point of this rambling post. I fired up Nettle and logged in with SSH as a vt200 terminal.

Sudo raspi-config

In the end I sorted out the mac authentication problem by editing its ….ssh/known_hosts file and deleting the offending old key.
Then SSH raspi-config and turned off Pixel doubling.

There must be some learning opportunities here.

Using Avalanche to VNC

Just out of interest, just today I installed Raspberry PI OS using Pi Imager, activated VNC Server, and tried to connect from Avalanche v0.28 … but connection fails with
No Configured Secirity Type is supported by 3.3 VNC Viewer.
The log shows
Server protocol version ‘005.000’, using ‘003.003’
So can I ask how you managed it?
I know the server is working because VNC Viewer connects from Windows ok.

I just installed the latest Bullseye based Raspbian on a Pi at work and could not connect to it via Remmina on Linux (even using VNC password, rather than UNIX login), which works for all my Buster based Pis at home. The problem is Raspbian comes with a RealVNC server, and it seems the latest version only plays nice with their own RealVNC client. I suggest uninstalling it, and replacing with the standard Linux x11vnc package.

brought up the configuration screen, but it was unusable.
It sort of works but there is no way to select the option you want to use except the last one “About” which was no help.

You can select an option by pressing ‘Space’.

So can I ask how you managed it?
I know the server is working because VNC Viewer connects from Windows ok.

You need to turn encryption off and create a VNC password
On the pi, alt-click on the V2 server icon

 >>V2 
    >Options ...
        >Security ...
            Encryption      >  prefer off
            Authentication  >  VNC password
        >Users and Permissions
            Standard user
            enter password  OK

This works on Buster and Bullseye.

You can select an option by pressing ‘Space’.

Thanks Chris – got it working now by using the space bar exclusively.
The problem was using a combination of space bar to select and enter key to instigate. This is the way I normally work on mac or linux.

I am probably exposing my ignorance here … but this OS is totally new to me!

@dave: Thanks … but currently I have no idea how to uninstall something and find something else to install.

@John: Thanks … but where is the ‘V2’ icon? I have a ‘Vsquiggle’ icon top right, but Alt-Click with any botton does nothing. It is running VNC Server 6.7.4 from RealVNC. I have tried setting Options → Security → Encryption to Prefer Off, but makes no difference. Buster & Bullseye mean nothing to me!

Welcome to the dark side, Martin.

Buster & Bullseye are just code names for particular releases of the Debian OS; Raspberry Pi OS has recently been rebased onto the latest release, Bullseye.

You want to use sudo apt install x11vnc to install that package.

Ok, here is what I’ve just done on that Pi switch to using x11vnc instead of RealVNC server, replace MYPASSWORD with your password.

sudo systemctl stop vncserver-x11-serviced.service 
sudo systemctl disable vncserver-x11-serviced.service 
sudo apt install x11vnc
sudo x11vnc --storepasswd MYPASSWORD /etc/default/x11vnc.pass
echo "X11VNC_OPTS=-xkb -nowireframe -forever -auth /var/run/lightdm/root/:0 -display :0 -rfbauth /etc/default/x11vnc.pass -rfbport 5900 -o /var/log/x11vnc.log -repeat -bg" | sudo tee /etc/default/x11vnc0
sudo systemctl enable x11vnc.service
sudo systemctl start x11vnc.service

There seems to be some confusion here. Raspberry Pi OS comes with VNC server built in, but not enabled.
If you want to avoid installing stuff via the command line do this:
Click on the Raspberry pi icon top left.
Click on Preferences
Click on Raspberry Pi Configuration
Click on Interfaces
Click on VNC enabled

V2 should now appear on the left side of the top icon bar
(you may need to reboot first – I don’t remember)

Now follow the instructions in the post about 5 posts up.

Or you could watch this 36 second clip I have just made and uploaded to YouTube

but obvs not on NetSurf

The problem is the VNC server in the latest Raspberry OS only seems to work with the Windows RealVNC client. If you want to use any VNC client, follow my instructions.

The problem is the VNC server in the latest Raspberry OS only seems to work with the Windows RealVNC client.

Thanks that is useful to know – but it does also work with !Avalanche which was what Martin was asking about.

All one has to do is search the forum, Paolo has given clues.

On Raspberry Pi OS left click on the VNC icon on the top bar. Click on the hamburger in the window that just opened. Click options. Click Security. In Authentication select VNC password, click Apply, and set the same when prompted.

Avalanche, and Remmina. and Mac screen sharing, are now back on the case. VNCviewer is still working.

Tested on Raspberry Pi OS bullseye 64bit.

update Further tested on Raspberry Pi OS’s bullseye 32bit and buster 32bit.

@John:

On the pi, alt-click on the V2 server icon

To an beginner like me that was confusing:
I could see no V2 icon … because I had alwaays read the icon as VR.
Alt-click did nothing … but RightClick gave access to Options.
Eventually I realised that the rest of the instructions were menu selections.
And it is indeed all working now!
(I am looking forwards to the YouTube release of your PiHole talk – my question was after I had just managed to install & use PiHole!)

@Druck: Sorry, but commands like that are what has kept me away from unix for decades!

Thanks for all the help.

@Druck: Sorry, but commands like that are what has kept me away from unix for decades!

I could explain how to do it from the GUI, but I haven’t got all night.

Alt-click did nothing … but RightClick gave access to Options.

Sorry brain fog – I meant to write Adjust-click.
Right-click is clearer but assumes you have not swapped mouse buttons.
Anyway glad you have got the VNC working.

I could see no V2 icon … because I had alwaays read the icon as VR.

Weird – you have caused me to look more closely.
It is neither VR nor V2 but Vnc with the n above the c
as in the following image:

Yes – that is why I ‘described’ it at one point as Vsquiggle!