certificate error when initiating a RDP session using Remmina

Shortly after running the latest version of Remmina a new message “certificate changed” popped up.

remmina remote desktop protocol rdp certificate details

As I connect to different VMs with the same IP address (e.g. with client A I connect to host “KA” and client B I connect to host “KB” using the same IP address 192.168.178.12) this message totally makes sense as each VM has a unique certificate. But when I click on “OK” to accept the new certificate I get an error message.

remmina remote desktop protocol rdp certificate details

Several posts on the web say that files in the folder ~/.freerdp/certs should be removed .. but this folder does not exist on my machine.

Others say they changed the RDP security from Negotiate to RDP .. but this also did not work for me.

Finally a blog post got me on the right track – there the programme xfreerdp was run via command line with the parameter /cert-ignore – this very parameter Ignore certificate can be configured right in Remmina .

remmina remote desktop protocol rdp certificate details

using Remote Desktop Gateway with Remmina

Previously I was starting a Windows VM to do nothing else but connect to other Windows machines or VMs using Remote Desktop Gateways. Several weeks ago I was asked why I don’t use Remmina as it uses FreeRDP and this has the feature implemented. With a quick search I found an answer (from 2014) that I would have to compile FreeRDP myself. It was also mentioned that there was a feature request on the Remmina GitHub repo which one should upvote. There I found the information that it was already implemented …

So I double-checked if I was running the current version of Remmina. The Linux Mint Update Manager also did not show any updates.

Remmina was installed in version 1.1.2 – support for Remote Desktop Gateway was added in version 1.2.0 (which is currently available as PreRelease).

The wiki mentions that there is an official PPA for Remmina 1.2 which one can add and install the latest PreRelease with the following commands:

sudo apt-add-repository ppa:remmina-ppa-team/remmina-next
sudo apt-get update
sudo apt-get install remmina remmina-plugin-rdp remmina-plugin-gnome libfreerdp-plugins-standard

After updating Remmina with the latest PreRelease I can now successfully connect using RDG without firing up a VM every time.

remmina rdg remote desktop gateway settings

toggle window “always on top” via shortcut

When I use Windows I still use the aged tool WinSplit which brings the shortcut “CTRL+ALT+O” with it. This keeps the current window always on top of all other.

I wanted this functionality (and the shortcut) also on my laptop which is running Linux Mint.

This works without any additional software as the functionality is built-in and available via the context menu of every programme icon.

https://cdn.gpunktschmitz.de/blog/183/00-manually-set-window-always-on-top.png

And a programme to add shortcuts exists also.

https://cdn.gpunktschmitz.de/blog/183/01-open-keyboard-shortcuts.png

So, starting the programme “Keyboard Shortcuts” and click the “Add”-Button.

https://cdn.gpunktschmitz.de/blog/183/02-add-new-keyboard-shortcut.png

Entering a name and the following as the command:

wmctrl -r :ACTIVE: -b toggle,above

https://cdn.gpunktschmitz.de/blog/183/03-enter-new-shortcut-command.png

Once the shortcut is added you click on the column “Shortcut” of if (where it says “Disabled”).

https://cdn.gpunktschmitz.de/blog/183/04-click-on-disabled-to-set-new-shortcut.png

Now you can add the favoured shorcut by simply pressing it.

https://cdn.gpunktschmitz.de/blog/183/05-press-shortcut-and-close.png

installing linux mint 13 (mate) on a fit-pc3 – xserver no screens found

i set up my fit-pc3 and had some trouble getting my xserver working .. here is how it went …

i was pleased to see a page in the wiki from compuLab but IMHO there are some points missing:

boot from usb flash drive

i changed the boot order in the bios (which you can enter via pressing “F2” during boot) but the screen was nothing but black. turned out that pressing “F1” randomly right after powering the machine it was booting from the usb flash drive.

linux mint 13 fails to boot

i also had to select “start in compatibility mode” to successfully boot the livecd

resolving xserver error – no screens found

after the installation finished the xserver would not start. some sites mentioned to simply update linux so i ran (after commenting “medibuntu” out in /etc/apt/sources.list)

sudo aptitude update
sudo aptitude upgrade

accepted any modified file to the maintainer’s version and restarted .. but nothing changed. so i follow the instructions from compuLab and installed the ati catalyst drivers using:

sudo aptitude install fglrx-updates xvba-va-driver vainfo

and restarted .. but still the xserver failed to start …

i finally cam across a forum post where the following command was mentioned

sudo aticonfig --initial

rebooted and the xserver was back again …

howto format a usb thumb flash drive

to format a usb thumb drive you need a software called “gparted”.

installing gparted

to install it use the following command:

sudo aptitude install gparted

or you may also use the “Software Manager”,

howto format a usb thumb flash drive

search for “gparted” and install it.

howto format a usb thumb flash drive

run gparted

after the installation run it either by starting it with the command

gparted &

using the terminal or you may also find it in the mint menu listed in the group “Administration”

howto format a usb thumb flash drive

or just type “gparted” into the search box.

formatting

select the device you want to format from the dropdown list in the top right corner

howto format a usb thumb flash drive

when you made sure you have selected the correct device right-click the partition and select “Unmount”

howto format a usb thumb flash drive

then right-click the partition again and select the format you want the thumb drive to have from the sub-menu “Format to”

howto format a usb thumb flash drive

apply the changes by clicking on the ‘return’-button “Apply All Operations”

howto format a usb thumb flash drive

you have to confirm the operations to take effect

howto format a usb thumb flash drive

once the thumb drive is formatted you may close all windows and mount it by clicking on it in a nautilus window.

workaround: slow printing pdf documents and images on the hp 2200 dtn

i tried everything to fix the slow printing of the hp 2200 dtn but nothing really helped .. the only thing seems to be to replace it with a different one (according to this forum post .. the third from the bottom) …

i have the fit-pc2 running 24/7 and there is also running windows xp in virtualbox on it .. so i thought why not configure the printer in windows xp and share it …

using this shared windows printer the pages are printed in no time …

Disable Wireless (Wifi) By Default On Startup

booting the machine with the physical wireless switch enabled the wifi was always enabled but the wwan was not …

as i would like to choose whether or not to enable any wireless connection i wanted to disable it by default …
i started by disabling the option “Connect automatically” at my wireless connection .. but that would not stop the wireless to start up enabled …

finding this forum post http://forums.linuxmint.com/viewtopic.php?f=53&t=58107#p353685 describing how to enable it .. it was just a matter of switching the boolean

open /etc/rc.local

sudo gedit /etc/rc.local

and add the following line right after the last line starting with a “#” and just before “exit 0”

dbus-send --system --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.DBus.Properties.Set string:org.freedesktop.NetworkManager string:WirelessEnabled variant:boolean:false