Linux Tutorial

Wireshark is a software protocol analyzer can examine the contents of all data packets in transit on the network interfaces used. The program reflects the heritage of Ethereal basing its operation on its own experience and technology developed by “predecessor”. The prerogative of Wireshark is to provide a detailed overview of everything that is happening on the local network by offering a graphical interface for easy use and easy to understand. Wireshark is able to identify the network protocols used for various types of communication and is therefore able to show the different encapsulations.

The strong point of this excellent protocol analyzer is certainly flexibility: thanks to special rules for sorting and filtering becomes so quick to extrapolate the data of interest from this information.

Wireshark provides a valuable aid to help experts in the identification of potential vulnerabilities of the systems used in the company (login credentials sent in clear text, suspicious activities perpetrated by clients on the LAN, the transit of sensitive information and so on).

Wireshark there are multiple versions, one for each operating system, be it Windows, Linux or Mac OS X.

Network Security Toolkit (abbreviated NRC) is a free package that contains most of the open source applications from the world of security. Among them is Wireshark but also a whole series of programs of particular interest to the network administrator: The complete list is available by clicking here. NRC is completely based on Fedora and acts as a Linux distribution itself.

In our case, we decided to install the Network Security Toolkit as a VMware virtual machine player. The advantages of this approach are significant: first, you will have a “virtual computer” that can be used to make control the data traffic between the servers connected to the local network as well as between them and the remote machines on the Internet.

1. As a first step, you must download and install the free VMware Player (the program can be downloaded by referring to this page). We proceeded to remove the Windows version and install it on a Windows 7 machine.

2. At this point, you can download the ISO Network Security Toolkit, by clicking here. The download can take several minutes to be completed (the file “weighs” in fact much, about 1.4 GB).

3. The next step is to launch VMware Player, click on the Create a virtual machine then click the option I will install the operating system later.

From the next window, you must select the operating system Linux as “guest” (the operating system that will run within the virtual machine) and Fedora Version from the menu.

At the onset of the third screen, you must specify the folder – hard drive – which will be stored within the virtual machine. Finally, you must indicate the capacity of the virtual hard drive on which the NRC will be installed later. At the box you can specify the Maximum disk size 20 GB leaving enabled Store virtual disk as a single file.

To complete the procedure, you must then click the Finish button.

4. After selecting, from the main VMware Player, the Fedora virtual machine you just created, you must click on the link Edit virtual machine settings.

By visiting the CD/DVD (IDE), you must select Use ISO image file, click the Browse button and specify the file-2.13.0-nst 1713.i686.iso previously taken from the Internet. This adjustment will launch the contents of the ISO file NRC.

Finally, click on Network Adapter and then choosing the option Bridged: Connected directly to the physical network will ensure that the Linux virtual machine to appear – to the other client systems connected to local network – as a “physical” for all purposes.

Confirming the choices by pressing the OK button, you can start the virtual machine (virtual machine links Play).

Installing Mandriva

Yesterday I had to install Mandriva on my PC. My preferred medium is the DVD, in fact, downloading the free version (iso 4.3GB) you get a complete picture with a lot of software available, you get cleaner installation and you have the choice of either desktop environment, both programs to be installed (also classified by category).

The problem is that the DVD should have a DVD and a DVD player on your PC when you install the operating system, for the second there are no problems, but I was lacking the first or last, and I did not want to go out and buy one.

Searching Google I found that you can install Mandriva leaving just downloaded the iso of the DVD to hard disk. To start the PC is still a cd or usb memory that allows the installer to start. This can be found in any Mandriva mirror in the path “official/2010.0/x86_64/install/images/“, adapted of course to the version and architecture used.

In this route there are several files, two are those that serve: all.img can be copied to the USB memory with the command

dd if=all.img of=/dev/sdb

(sdb is the USB meoria) boot. ISO is an ISO image to burn to a CD.

When booting the PC with one of the pictures above, a menu that asks which installation method you want to use. You can choose to do the network installation, hard drive or if you choose the path you will be asked where is the iso image, after these steps, the installation proceeds in the traditional way and very quickly.

For the record, this time I wanted to change the desktop and choose GNOME, you can still install KDE in the future, choosing the package manager “task-kde4” or “task-kde4-minimal” if you want to do a minimal installation.

Dropbox

Dropbox is a great service that allows you to save your files online and share them with friends. Once installed on your PC appears a folder, all files in this position will be saved online. In the free version is available to 2 GB and 8 GB will be brought to performing some steps or doing other users inscribed, for each of these steps are added to 250 MB.

Dropbox can be installed on Windows, Mac OSX or Ubuntu. But there is the possibility to install even on distributions that use KDE and Dolphin as a file manager, such as Mandriva.

First you need to install the daemon, which is the program that is open and takes care of data synchronization, can be downloaded in two versions for each architecture:

Dropbox 32-bit
Dropbox 64-bit

The downloaded file is compressed and contains a folder called. Dropbox-dist, as seen from the starting point, this is to display hidden so you have to enable viewing of hidden files.

Copy the extracted folder in your home, open the configuration panel of kde and the Advanced tab, click “Auto Start“, here the script to add “dropboxd” located in the directory you just extracted and set to run at startup. Restart kde and you will see the icon appear on Dropbox and account setup wizard.

One thing you immediately notice is the lack of integration with dolphin, then no icon will not appear, symbolizing the updated files, there is a plugin that integrates the unofficial Drop-in dolphin.

The plugin is provided as a source or as a deb package for 64-bit Kubuntu. I use 64-bit Mandriva and installation of the package turns out to be quite simple. The deb package is an archive can be unpacked with ark, it contains a file called data.tar.lzma which in turn is a repository within which there is a directory tree that plays the file system of a linux distro, then simply move the files in its directory in the root of your filesystem. The only difference I noticed in this case is that of mandriva kde libraries are in /usr/lib64/kde4, while on kubuntu in /usr/lib/kde4.

Kde restart again and you will find icons that indicate the synchronization status of files and folders. I actually noticed that the plugin is not too stable and rarely makes dolphin crash, nothing great though.

If you are interested, Dropbox can be found at: DropBox

Linux Mandriva

The support they have received no developers of free software and the struggle for survival are themes familiar to the creators of Mandriva. This distribution is now more than 10 years at the forefront. Initially based on Red Hat, its first versions (when it was still called Mandrake) included KDE 1.0 and most interesting programs for users and for companies.

What is certain is that Mandriva has always tried to treat both markets, resulting in a success thanks to the fact that, among the first distro, integrated assistants and, of course, has continued to improve over time. In addition to various standard applications inherited from Mandrake, as KDE 4, various firewalls and backup tools, offers its users a wide group of programs like Koffice Mandriva Smart Desktop, OpenOffice, Firefox, Moovida, …

Mandriva Linux 2010.0

Mandriva is the fruit of the union of Mandrake, Connective and Lycoris. From the time when Mandrake was only one version of Red Hat with KDE time has passed, and now Mandriva is certainly one of the giants of free software, and as a trading power and as a product to offer to users. It is distributed very updated and edited graphically. And is’ always stood out for its orientation to the desktop market, thanks to the configuration tool provides its users with tools to help you step by step to configure your PC the best to enjoy the full OS.

What’s new in Mandriva Linux 2010.0 includes the inclusion of the latest versions of KDE and Gnome, reducing boot times, hardware present on the optimization of the recognition and integration of Moblin netbook, making it even faster and more usable ultraportable on the distro

Safety: Mandriva in the past (when it was still only Mandrake) was affected by the decision to cater mainly to the desktop market and, consequently, some choices made in order to provide a system as simple to use. Over time, however, has managed to improve from this point of view, introducing new software.

Simplicity: The strength of Mandriva has always been the simplicity and it is always the beginning bar table reference for novice users, looking for discharging them at ease with their instruments.

Software Included: Many current and complete packages are available for Mandriva Linux, which can not be missed really nothing to its users: in a simple way you can get every application we need.

This distribution is one of the more usable thanks to the enormous amount of their developments, which ensure both the recognition of most of the hardware configuration of programs and devices.

The classic partitioning used in most home installations is based on the MBR (Master Boot Record) and MS-DOS partition table.

With this system you can have a maximum of 4 primary partitions or up to 3 primary partitions, extended partitions and logical partitions within it endless.

The main limitation of this architecture is given by the rigidity of the resources of this organization. The partitions are fixed and can not be separated into multiple disks can not be changed without removing and space for the file system is fixed, can neither grow nor diminish without having to remove everything and redo the partitions.

Imagining multiuser installation, if the disk is completely filled with the only solution is to buy a new drive and transfer data to, resetting the permissions as they were originally with the high cost of time, or move the data elsewhere, solution is obviously not easy to apply multi-user.

LVM (Logical Volume Manager) is revolutionizing the concept of space organization providing a dynamic allocation of space.

Structure of LVM

The figure above shows the general operation of LVM in the presence of several disks.

Each physical disk contains within it a number of partitions, and these can be used normally to mount a file system (as in the case of pointing to sda1/boot without joining LVM) or LVM may be used.

Each partition is inserted in LVM is called a physical volume (PV = Physical Volume).

Some or all physical volumes can be assigned to a volume group (VG = Volume Group). This allows you to use multiple disks/partitions together into a single data structure. The use of dedicated hardware greatly improves the operation, allowing the use of all disks connected synchronously.

The sum of all partitions dedicated to the volume group defines the size of the group, so that once you run out of space just to buy a new disk, add it to the group and its capacity will be added to the space group. In this way, we ensure the scalability on massive scale.

All the space dedicated to a volume group can be divided into one or more logical volumes (LV = Logical Volume) that will be used by the system to create the file system, simply by formatting them in the way you want, as ordinary partitions.

Advantages of using LVM

The advantages of using LVM than traditional partitioning are numerous:

• Total capacity expandable without moving data
• Dynamic allocation of space without reformatting, including adding, removing and replacing disks
• Association of names to a group of devices, regardless of which partition is used to deliver a volume group
• Breakdown (striping) of data across multiple disks
• Cloning (mirroring) volume
• Creating snapshots (snapshot) of a logical volume to get copies of the same data at the time of the snapshot