Category Archives: tutorial

How to configure Firestarter to use VPN services on Linux

VPN Linux In my experience Firestarter is a effective firewall and, on Linux, it starts automatically every time we boot up Ubuntu. But, when I decided to use a VPN tunnel through openvpn, I had some connection problems. In fact I was able to initialize my VPN services but, after a while, all the internet connections were mysteriously shut down.

The “problem” was Firestarter which cut off the connection as forbidden considering my inbound/outbound Policy.

To solve this matter you have to open a tunnel on Firestarter to allow VPN working:

1- open the configuration file my VPN provider gives to its users (generally its a text file containing all the configuration info used, in my case, by openvpn) and I searched for the IP address of the default starting connection used to authenticate the VPN services (e.g. 177.458.563.25). Save somewhere or memorize this VPN IP address.

2- open a Terminal and type:

sudo nautilus

3- using nautilus go to File System (it’s before home folder) and open etc–>firestarter and open the file user-pre using Gedit (or your preferred text editor)

4- the user-pre file is usually empty so don’t panic and write these lines into it:

iptables -A INPUT -j ACCEPT -s xxx.xxx.xxx.xxx -p esp
iptables -A INPUT -j ACCEPT -s xxx.xxx.xxx.xxx -p udp -m multiport -sports isakmp,10000
iptables -A INPUT -j ACCEPT -i tun+
iptables -A OUTPUT -j ACCEPT -d xxx.xxx.xxx.xxx -p esp
iptables -A OUTPUT -j ACCEPT -d xxx.xxx.xxx.xxx -p udp -m multiport -dports isakmp,10000
iptables -A OUTPUT -j ACCEPT -o tun+

Now you have to substitute the xxx.xxx.xxx.xxx with the VPN IP address you have found at step 1 (in my example was 177.458.563.25).

5- Save the user-pre file and close Gedit and Nautilus

6- open a new Terminal and restart Firestarter typing:

sudo /etc/init.d/firestarter restart

That’all! Now your VPN works on your Linux computer and Firestarter has accepted a new Routed IP Tunnel into its allowed policies configuration.

Solve audio troubleshooting on Ubuntu and start planning to migrate to another Linux OS

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It was just a simple system update which dropped off audio on my Ubuntu 12.04. It was really strange to admit that I had experienced a crash (better: an audio crash) on a Linux but the 12.04 Ubuntu actually caused similar problems to a numerous bunch of long-term aficionados around the world.

The real problem with the last Ubuntu versions is that this OS is not supporting properly “old” hardware as it did previously during so many years. Reading some other bug reports on the web I discovered that these audio troubleshooting crashes happen principally to “old” IBM ThinkPad and Dell. I hope Ubuntu developers will consider to solve immediately these kind of issues or many users certainly migrate to other Linux version.

In any case the best and complete guide to solve audio troubleshooting has been developed by Ubuntu itself. The guide is very detailed but, if you want to definitively solve this bug, you have to spend more or less 40 (forty…. sic!) minutes and follow all the 17 (seventeen… sic!) steps.

In my case the audio was back after the first step and I decided not to follow the other instructions but the audio troubleshooting comes back, more or less, every two months. Just to you if you want to spend 40 minutes only one time or a couple of minutes every two/three months.

When I consider all the problems I had with Ubuntu on “old” hardware starting from the 12.04 version, my advice is to start thinking about a migration to another Linux OS. I am testing some Ubuntu alternatives and in the next weeks I will post something about the tests I’m doing on old laptops. Stay connected!

How to install Ubuntu 12.04 on old computers with non PAE CPU

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When I tried to install Ubuntu 12.04 on an old ThinkPad X40 I was surprised to discover this warning on my screen:

This kernel requires the following features not present on the CPU:
pae. Unable to boot - please use a kernel appropriate for your CPU.

In few words I wasn’t able to install Ubuntu 12.04 because the kernel on Ubuntu 12.04 was not supporting my CPU and I was really upset because I have always promoted Linux distributions as the most versatile and appropriate OS to keep using “old” hardware.

Sincerely, as described in an older post, I previously decided to install MATE desktop environment because the graphic cards on many laptops didn’t support Unity and Gnome 3 but this was the first time I had to renounce the installation of Ubuntu. I didn’t want to surrender to this difficulty (that appeared to me as a bug)!

First of all, I discovered that pae is “a feature to allow 32-bit x86 processors to access a physical address space (including random access memory and memory mapped devices) larger than 4 gigabytes“. After I clarified this point, I was not sure that my processor was totally inadequate to support Ubuntu 12.04.

After some web surfing I discovery that there are two easy solutions to avoid this problem.

1 – As first solution you can install Lubuntu (my choice) or Xubuntu on your computer then you can install the ubuntu-desktop using the Package Manager.

2 – If you prefer not to use the Package Manager you can install Ubuntu 11.04 or 11.10 and then upgrade Ubuntu to 12.04.

More in general, it is also possible to assume that if you have a non PAE CPU, your hardware could not be able to support the Unity desktop. For this reason you can keep your Lubuntu – Xubuntu (based on the light but effective LXDE desktop) or switch your desktop environment to Gnome (the Classic, of course) installing the gnome package instead of ubuntu-desktop.

In any case, if you want to know if your CPU supports pae you have to open a Terminal and type:

grep --color=always -i PAE /proc/cpuinfo

If something like “flags: fpu vme de pse tsc msr pae mce cx8…” outputs on your Terminal, you have a pae CPU otherwise your CPU doesn’t support pae.

Video – Linux Wifi Mac address spoofing by peruzfinest08

Video – Firefox Addon TrackMeNot by LinuxWindowsMacHilfe

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How to permanently remove files in Ubuntu/linux and make them unrecoverable by NickMcDTV

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How to shred (permanently delete) files from your Hard Disks on Ubuntu Linux

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In our last post we examined the possibility to recover deleted data from USB keys and disks. Today we want to focus your attention on the proper way to destroy sensitive data from your disks.

On Ubuntu you have the possibility to move any file to the Trash but, as we demonstrate in our last post, anyone has the possibility to recover them using a simple, basic GUI, program called PhotoRec.

If you want to be reasonably sure that none will be able to recover a file you decided to permanently delete you have to use the Shred command. Shred is native in Ubuntu Kernel and literally delete your files overwriting them repeatedly with arbitrary data. After you delete a file with Shred you can be sufficiently sure that recovering procedures will not succeed.

As usual we must warn you that technology is rapidly evolving and what could be considered sure today, tomorrow will be out of date! So, if you think you need to preserve your privacy in the best way, don’t forget to change the hard disks regularly and mechanically destroy your old ones. Sincerely we hope our readers haven’t this kind of need.

To start using Shred on Ubuntu you have to open a Terminal and type:

sudo shred –help

In this way you will visualize the grammar and all the possible options offered by this program.

The correct grammar to use Shred is:

shred [OPTIONS] FILE

or, if you want to shred a entire partition:

shred [OPTIONS] /dev/[HDA9]

The possible options are:

-f, –force    change permissions to allow writing if necessary
-n, –iterations=N overwrite N times instead of the default (3)
–random-source=FILE get random bytes from FILE
-s, –size=N   shred this many bytes (suffixes like K, M, G accepted)
-u, –remove   truncate and remove file after overwriting
-v, –verbose show progress
-x, –exact    do not round file sizes up to the next full block;
this is the default for non-regular files
-z, –zero     add a final overwrite with zeros to hide shredding
–help     display this help and exit
–version output version information and exit

In our experience, to operate in the fastest way, we decided to add Shred on the Nautilus Menu and have the command ready with a simple right click on the mouse.

For this reason you have to open a Terminal and type:

sudo apt-get install nautilus-actions

Then you launch the program following this path: System->Preference->Nautilus Actions Configuration.

Last, you have to configure Shred filling e.g. the following parameters:

Label: Shred
Tooltip: Shred utility to securely erase files
Icon: gtk-dialog-warning
Path: shred
Parameters: -f -u -v -z %M
Filenames: *
Mimetypes: */*
Appears if selection contains: Both
Be sure to check the box “Appears if selection has multiple files or folders“

To finish your configuration, do not forget to open again a Terminal and type:

nautilus -q

nautilus

Recovering deleted files from USB disks on Ubuntu

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Everyday we use USB keys to transfer data without transmitting them through the t. The USB keys and portable disks are small, light and their data capacity allow us to move in privacy huge files. This idyll sometimes is broken by a fatal mistake: we unintentionally delete an important file. Normally, if we are smart we recover the erased file in the Trash but in other situations when we realize the mistake we had made is too late.

In this circumstances is very import to stop to use our USB key or portable disk till we are able to use a good software for data recovering. On Ubuntu you have a wise number of dedicated software that can do this job for you, the most powerful run on Terminal as testdisk, foremost, and scalpel but you can also use a “minimal GUI” software as PhotoRec.

PhotoRec is very intuitive to use and it is able to recover many data formats from jpeg to db. After you install it using Synaptic Package Manager or the Software Center you can launch it in Terminal with:

sudo photorec

Immediately a GUI Terminal interface appears and you have just to follow the instruct ions you visualize on your monitor.

Using the arrows and the Enter keys you have to:

1 – Choose the USB device from where you want to recover the data

2 – Select the partition table (usually Intel)

3 – Specify the partition table

4 – Select the right filesystem where the data were stored

5 – Decide if you want to try the data recovering from all the free space

6 – select the directory where you want to store the recovered data. IMPORTANT: do not store the recovered data on the same USB key you are scanning for recovering

7 – Wait till PhotoRec finishes the recover operations.

PhotoRec is fast and, during our tests, we were able to recover almost the 100% of data. Not bad!!!

How to repair a bad screen resolution on the IOMEGA Screenplay Pro HD

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This is the situation: you have a IOMEGA Screenplay Pro and while you where trying to find a better output resolution for your monitor you accidentally (or not) selected the HD option and now you are not able to visualize anything.

In few words this is the easiest problem you can afford but also one of the worst because you are not able to visualize the menu and so you cannot revert the right monitor resolution.

I visited many websites but unfortunately I didn’t find any forum or post about this topic. In any case I like to focus your attention on this ScreenPlay Pro HD wiki which is a real mine of information and tips about this specific hardware.

So I tried to “play” with the Screen Play Pro HD remote but I was not able to find a solution without visualizing anything on the monitor.

At the end, when I was thinking to reset the Screenplay and loosing all the data contained, I tried to use an old solution I used different times with other stuff: I pressed the power button for more than 10 seconds while I was switching on the device.

Something happened because the monitor showed me the Screenplay boot up window for a couple of seconds. At this point I pressed the NTSC/PAL button and the Screenplay Pro HD menu was visualized on my monitor again.

A quick trick to have the USA google.com always ready

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When we use our computer outside the USA, the browser is automatically redirect to the local google page. This is not a problem when you are just surfing without any specific goal but often the google automatic redirecting is very annoying because also your search will be customized depending where you are and the language spoken in that country.

To easily avoid this problem you can instruct google to ignore your location just typing http://www.google.com/ncr and your searches will always start as a USA customer. In fact NCR stands for NON COUNTRY REDIRECTING and allows you to use the USA google.com.

On the contrary, if you are in USA and you want to customize your search focusing to a particular foreign country you have to just add a suffix to the google search results link.

In other words, if you are looking for operating banks in Ireland, you have to:

– search into google as usual, typing the word “bank”

– go to the end of your search url and add &gl= followed by the country code where you want to focus your research (de or in or ir or it or …) eg: &gl=ir

Last but not least, if you prefer to influence the google research interfering just with the results language, goes to the search settings and choose the languages you prefer.