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).

A little ‘are coming to me once all components of the new server. Now only lacks a hard drive and then I can install the operating system (Debian GNU / Linux). On this occasion also arranged for a piece of my workstation since I added the last album, last year, I never had the opportunity to configure the best partitions.

The CPU I chose for the server supports Intel® VT and this is making me look into the option to virtualize some service.

This server will have to perform several tasks:

• IMAP Mail Server
• Web server for development
• Backup servers

Dovecot: IMAP mail server with Debian

To manage electronic correspondence will continue to rely on Dovecot. This is an open source IMAP and POP3 servers by high standards of security, very fast and fully compliant IMAP (source), in contrast to many other IMAP servers such as Courier-IMAP and Cyrus (both open source) or Zimbra, Gmail or MS Exchange that are not completely standard and does not fully meet my needs.

Dovecot, finally, in addition to the excellent technical features is also easy to configure.

How to install and configure Dovecot with Debian

The installation is very fast, as most of the software on Debian. Just the classic:

apt-get install dovecot-imapd

to have the program installed on your system (less than ten megabytes if I remember correctly).

The next step is to configure the IMAP server by changing a few lines in the configuration file /etc/dovecot/dovecot.conf to specify the protocol that you want to use and the path to, in my case:

protocols = imap imaps

and

mail_location = maildir:~/Maildir

At this point, if you do not need special configurations, the IMAP server will be configured.

How do I send and receive mail with Debian server?

However there are two more pieces to complete the setup of email on the server: we also need an MTA (mail transfer agent) and a service to retrieve email from various accounts I have.

I chose Postfix as MTA for many years: it is a stable, secure and efficient. The configuration in the case of a small server is pretty straightforward, although at first glance it might seem otherwise.

To download the emails using fetchmail instead (along with SpamAssassin). Here too a classic and functional solution.

Web server with Debian development

The server, in addition to managing email, also serves to build web applications, to implement and test the products without having to install software “server” on the workstation and, especially, not to be bound to a single machine for development.

Apache and MySQL are therefore the logical choice for this type of activity.

The process of installing and configuring Apache and MySQL on Debian is very easy. With apt-get the packages are installed in minutes and very few are enough to set up operations: MySQL is configured via a wizard during installation and Apache only needs some things in the configuration files.

Backup servers, Debian and Rsync.

The third and last task of the server is to make copies of data storage, document and archive projects. As far as the backups are very demanding and, thanks to the new server, the data will be even more secure thanks to an additional backup made with a small RAID.

The disks in the RAID will be used to back up the backup, although I consider the current backup of RAID as a backup system ...

To make backups using rsync. Although I chose this software because it combines ease of use with high performance. Rsync the data through the workstation and server are periodically copied to disks dedicated to backups.

Virtualize or not to virtualize?

With the new server I would get a more reliable and safer than the old one, which however is still doing its job nicely. Virtualize some services could be very useful to separate the functions related to the development of mail handling.

The host system may look to make backups and allow the execution of the two guest systems, the mail server and web server for personal development. Before making the final setup I will still make a little ‘test to monitor the performance of this configuration.

If you develop web applications or websites you will find that owning your own web server for development is an extreme comfort.

It gives you the ability to operate in an environment where you have full control. You can configure it to be as similar as possible to the environment in which the final end your website / web application to use or take advantage of particular modules and extensions, not normally present in a basic hosting plan, and assess Based on the experience gained as hosting and choose services that require a time ready to go “into production”.

Where to install the server

First, to create the server you need to choose a car that can accommodate. A web server, especially if it has a purpose purely “experimental” (probably so you will have access to which only you) does not require special hardware features. Okay then your old PC has fallen into disuse. Basically you just have a machine that has a motherboard, processor, hard drive (even a few gb), ram (considering that you do with 512 mb sparks, but not enough) and a network card. No matter if your video card is integrated, without 3D acceleration, however poor or obsolete.

As an alternative, and it is that I prefer, you can use a virtual environment like Virtual Box.

Choice of distribution

A web server is a server-respecting lampp (Linux + Apache + MySQL + PHP + Perl). This environment is certainly the best condition possible to develop a website.

The software in question is compatible with any Linux distribution patterns, so you can choose the Linux distribution that best suits your needs.

We say that the distributions that are popular are CentOS, Red Hat, Debian and Fedora (probably the first two solutions are most welcome as they are compatible with cPanel).

There are also distributions pre-configured to be used as a server lampp, such as this, which is based on Slax (light distribution).

My choice: Ubuntu Server on Virtual Machine

Although there are definitely more performance distributions of Ubuntu for use by web servers, I also opted for Ubuntu Server because I’m not in a condition that forces me to seek the maximum possible performance. Ubuntu is also a distribution on I have more experience, and this makes me feel more at ease as regards the installation of packages and resolve any problems.

I used a virtual machine (with software from Parallels) I has a 4 GB HD (for my needs are more than enough), a 512 ram and a 32mb video card with no 3D acceleration support. Obviously I have not selected any sound card.

The link to download the latest version of Ubuntu Server is this. Not dwell on the installation phase because this is not very different from a normal Linux installation and is also well documented on the web.

When installing Ubuntu Server install will ask what kind of business, simply select lampp Server and OpenSSH servers.

During the installation you will be asked for minimal information (user name and password and the MySQL user’s password), while the rest of the operations will be carried out automatically.

Installation Complete. And now?

Now the system is ready for use. And it will be a text-based system. You can decide to control the screen of the virtual machine or via ssh from the terminal operating system of your “host” (the main one).

To test the operation of the server, login and enter the virtual machine

ifconfig

This command will return the list of connected network cards and will allow you to identify the IP address of the server. Enter the ip address in a browser. If you see a page that says It Works! it means that the server is working.

The server accessible on your network

If you want to extend your network to access the Web Server, you will have to search through the network settings of your virtual machine, one that refers to the Bridge. This bridge (the bridge for the note) allows you to enter the server you are connected to the network. You can then open the pages, accessed via ssh or ftp, by the other PC connected to the network.

Even in this case the virtual machine type ifconfig to obtain the address that was assigned by the router, and use it to connect to the server from other PCs on the network as well as the host.

The folder that will contain the site

In the real host, usually, the folder that contains the site is public_html. Create a folder with that name in our user folder by typing:

mkdir/home/USERNAME/public_html

Web users’ folders

As you know you can create multiple users and give them each a web folder (public_html) that will be accessible by typing in your browser http://indirizzoipdelserver/~username/

To enable this feature, (also in the case of a single user) on the terminal type:

a2enmod userdir

to enable the form needed.

Finally you will need to assign permissions to the folder public_html tastes, adding that the group owner www-data this time by typing:

chgrp www-data /home/USERNAME/public_html/

FTP Access

To be able to upload files via FTP on the server you will need to install an FTP server. My choice, shared by many sysadmin, has fallen on pureftp.

To install on Ubuntu Server pureftp logged by the virtual machine or via ssh and type:

sudo apt-get install pure-ftpd

Now type (one line at a time):

sudo groupadd ftpgroup
sudo useradd-g ftpgroup-d /dev/null-s /etc ftpuser
sudo pw useradd USERNAME-well-u ftpuser-d /home/USERNAME/public_html
sudo pure-pw mkdb
sudo ln-s /etc/pure-ftpd/pureftpd.passwd/etc/pureftpd.passwd
sudo ln-s /etc/pure-ftpd/pureftpd.pdb/etc/pureftpd.pdb
sudo ln-s /etc/pure-ftpd/conf/PureDB/etc/pure-ftpd/auth/PureDB

Now you can access via FTP using an FTP client and any username/password you choose.

Upload an index.html file with any content within your public_html folder and type http://indirizzoipdelserver/~username/ to test definitively the operation of your web server.

Until next time!

For the moment you are already able to access the server via ftp and ssh, upload files and create html and php pages displayed at http://indirizzoipdelserver/~username/. To reach the state of the art you need to configure MySQL, which will allow you to install the cms such as your web server suite. For this next article will be devoted to this important task. Do not miss it!

Faithfully following the guidance of UhrPablo Garcia http://geekyprojects.com/ubuntu/how-to-install-vmware-7-on-ubuntu-11-04/ I was able to install, something already done in Windows 7, VMware version workstation under Ubuntu. Result: MAGNIFICENT!

For issues of work/play I created three virtual machines:
WINDOWS SERVER 2003
WINDOWS XP
Lion OSX 10.7

We’re going to walk anyway. Install VMware.

Download the program, homework help, from here http://downloads.vmware.com/

Remember to download the program you need to register, partly because the program is free for personal use and with limited capacity. You can only create virtual machines with this version. If you want to run them separately, you must have a package called VMware Player which is also free and is included in the Workstation package but is not integrated in the package if not affordable.

To download the package you are looking just right for you, and you reach it from here and download it in your downloads folder. Remember that when you click on the file to download you have to click on “save link as”. If you do not, your browser will download a part of the file will give you an error during installation.

Just downloaded, open a terminal, choose the directory where you placed the downloaded file and run the file

sudo sh VMware-Workstation-7.1.4-Full-385536.i386.bundle

NOTE: The command refers to the 32-bit version, adapt for your needs.

This will open the GUI installation of VMware and not have to do is go on … ..
Done. The package is installed and you can start it from Applications/System Tools

Simple is not it?

I had already created three virtual machines under 7, I simply said to the folder where it was VMware virtual machine and voila, done! Good job!

VMware Server is a version of IBM’s virtualization software. Unlike Workstation, VMware Server only needs an activation key free, you no longer get by registering at the site of VMware in order to use this program without paying a Euro.

Requirements

As a host operating system supports both Windows and Linux.

The processors are recommended Pentium II, Pentium III, Pentium 4, Pentium M Xeon EM64T and the. Among the AMD Athlon are, Athlon MP, Athlon XP, Athlon 64, Turion 64 and Opteron. The minimum memory is 512MB, while the maximum is 4GB for processors that do not support the extension of PAE and 2GB memory addresses when using Linux kernels 2.2.x

The Windows operating systems supported are Windows Server 2003 Enterprise and Windows Server 2000. The list of systems includes the penguin Red Hat Enterprise Linux 3.0, Red Hat Enterprise Linux 4.0, Red Hat Linux 9.0, Red Hat Linux 8.0, Red Hat Linux 7.3, SuSE Linux Enterprise Server 10, SuSE Linux Enterprise Server 9, SuSE Linux 9.2, Suse Linux 9.3, SuSE Linux 10, SuSE Linux 10.1, openSUSE 10.2, Mandriva Linux 2006, Ubuntu Linux 5.04, 5.10, 6.06, 6.10. Kernel 2.2.14-5.0 is not supported. For both families of operating systems are required Perl 5.005xe a browser including Internet Explorer, Firefox, Mozilla, Netscape Navigator.

The virtual machines that are supported are those that can be used as a host more: Windows XP, Windows 2000, Windows NT 4.0 Service Pack 6a, Windows Me, Windows 98, Windows 95, Windows 3.1, MS-DOS 6.x, TurboLinux, Novell Desktop Linux, NetWare, FreeBSD, Solaris 10.

Installation

Attention to two different versions of VMware do not live together peacefully on the same host operating system, so if you install VMware Server will not be able to install the Workstation.

The installation plan to install VMware Server on the computer that will run the virtual machine and another installation of the VMware Server Console on a client computer to manage virtual machines remotely.

Using a Microsoft operating system as a server simply run the installer for VMware, choose the type of installation.

That includes full VMware Server, VMware Management Interface, VMware Server Console, API VmCOM, VmPerl API, the API programming and VMware Disk Mount Utility.

After the procedure, the software will be installed.

For systems with Linux you can use the package already compiled for VMware Server also if you want to use the Console (VMware-mui-. Tar.gz) and the Management Interface (VMware-server-console-. i386.rpm) you should download the relevant packages from the VMware site.

It begins with the command as root

# rpm -Uhv Vmware-server-.i386.rpm

In the end, you must enter

$ vmware-config.pl

and answer questions.

To install the VMware Management Interface you should copy the gz file in the tmp directory, then unzip and run the vmware-install.pl vmware-mui in the folder-distrib. When the configuration is finished you can start installing the Server Console.

The installation of VMware Server Console on a Windows host is resolved by running the installer, while Linux will need to download the zip file from the VMware site and unpack it in the tmp directory inside there are two files: one is the packet format rpm and the other is a tar.gz archive to be used on systems that do not use the packet format designed by Red Hat

To end the procedure is necessary to execute the command

$ vmware-config-console.pl

Answer the questions.

To install the console on a client workstation or on another computer from which you connect to the server, you must first install the VMware Server Console programming APIs, the API and a Windows client VMPerl also VmCOM API.

Logging of security and virtual machine

With VMware virtual machines can be managed remotely with using VMware Management Interface, which is a Web tool, or using the Server Console, similar to a remote assistance software.

Shut down a virtual machine: permits

There are four different levels of access to virtual machines: Exploring the virtual machine, interaction with the virtual machine, configuration, administration of virtual machine and host.

To explore the virtual machine is the ability to connect to the virtual machine to check if you turned on or off, but you can not interact with it. To explore a permissions must be set to Read in its configuration file with a. Vmx

Interact with the virtual machine is to have the opportunity to change the status (on, off, suspend, restart) and connect or disconnect removable devices, but can not be added or removed other hardware. To access this level in the configuration file permissions to be Read and Execute.

Having permission to configure the virtual machine you can add or remove virtual hardware. The permits are to be imostati Read and Write.

To administer a virtual machine and the host running VMware Server requires Read, Execute, Write, for that particular virtual machine, using Windows user account must be a member of the Administrators group, but with Linux you need root access to folders containing the files of the virtual machine. The administrator can change the amount of memory available to the various instances, or change the type of network between virtual machines.

When you create a virtual machine by default this is inaccessible to other users (not explored), then to make it accessible to others must change the permissions to the configuration file on the machine.

To change the permissions on Windows, the administrator (the only authorized) looks for the configuration file of the virtual machine, clicking the right button select Properties from the popup menu (Properties), click the Security tab (security). Here you can choose which groups and which users are allowed to give or revoke, restrict access or activate other.

If you use Linux, the procedure is a bit ‘more laborious.

When you create a virtual machine, the user becomes the owner (owner) of file configuration and get the permissions Read, Write, Execute. That belongs to the primary group the user is granted Read and Execute, while other users or members of groups to which the owner is only left Read.

When you install VMware Server is possible via the configuration program vmware-config.pl when setting permissions to change the behavior.

Authentication

When you connect to a virtual machine using the Console or the Management Interface is a request for user name and password. If authentication is successful you will have access to exist virtual machine using the permissions you have. Both the user name and password for the network travel appropriately encrypted by default, the administrator or root user can disable SSL if you do not want to use this service.

Logging

Using Windows as a host logging information is sent to the Event Viewer. The activities that are logged are: change of state of a virtual machine, the removal or inserimeno a virtual machine in the list of virtual machines available to a user, deleting a virtual machine, and of course every message warning or communication originated from VMware Server.

To observe this operating system for logging in Event Viewer, just log which is located under Start> Administrative Tools> Event Viewer.

Among choose the Application log to see the events generated by VMware Server.

To change the type of logging you must modify the virtual machine configuration file (.vmx) by changing variables eventlog.win.message = TRUE and FALSE = FALSE TRUE eentlog.win.register.

To set the logging of all virtual machines managed by the host can modify the VMware Server config.ini which is typically located in C:\Documents and Settings\All Users\Application Data\VMware\VMware Server

Soon there will be additional articles about VMware Server.