If you are using Linux Desktop Operating System and do not want to set up an email server, use GMail account to relay emails. On Desktop OS, we can use GUI Email Clients, which supports POP3/IMAP to send an email but how about /usr/bin/mail or from cmd prompt? To fulfil your requirement, you need to install a simple program called ssmtp. It accepts a mail stream on standard input...

The mysqldump client is a backup program originally written by Igor Romanenko. It can be used to dump a database or a collection of databases for backup or transfer to another SQL server (not necessarily a MySQL server). The dump typically contains SQL statements to create the table, populate it, or both. However, mysqldump can also be used to generate files in CSV, other delimited text, or XML...

Sometimes you may get old web results and old webpages even after updating the web pages. That means, DNS cache holds the problem. To solve this problem, execute below command to flush DNS cache.  # /etc/rc.d/init.d/nscd restart

In Linux you can use faillog command to display failed login attempts or you can set login failure limits. faillog formats the contents of the failure log from /var/log/faillog database / secure log file. It also can be used for maintains failure counters and limits. For RHEL/CentOS Linux 5.x, you need to modify /etc/pam.d/system-auth file to monitor or track failed login attempts. You need to...

SARG – Squid Analysis Report Generator Configuration is a tool that allow you to view “where” your users are going to on the Internet. SARG provides many information about Squid users activities like, times, bytes, sites, etc… Download latest version of SARG from here. # wget http://...

Wireshark Network Analyzer is use full to track network packets. To sniff MySQL packets and decoding it, we will use mysqlsniffer. Note: This will not usually work for local connections. First, install libpcap-dev, which is the development library that allows an application to sniff network packets. $ sudo  apt-get install ...

After downloading ISO file from Fedora/CentOS, you can check the integrity of the ISO-file with a checksum, the md5sum. The mirror will offer you a separate text file to download with a 128 bit string of characters. This string has to be exactly the same as the one you get when you do: # md5sum file.iso 0c0f8ff9b6fb60a4778288de0d9e7f46  file.iso We assume that, you have downloaded ...

Fileop utility does file operation on the filesystem and gives the ops/sec for each operation. This tool will be useful to test your filesystem performance as well as storage performance. Or, if you are going to select a filesystem or storage that is going to host huge number of small files (like source codes), then fileop can be used for benchmarking. First Install  ...

Every time I connect to Linux server, I receive the same message and I’m getting tired of seeing it, so I decided to change the message to something else. Here’s the message that I get every time: [root@server1 ~]# ssh linuxarticles.org root@linuxarticles.org's password: Last login: Mon Oct 11 18:58:43 2010 from loc...

Fedora, CentOS and RHEL allow the console user to perform an interactive system start-up by pressing [I] key. Using interactive boot, attacker can disable the security services and may get access to system. Open etc/sysconfig/init file and disable PROMPT option, # vim /etc/sysconfig/init PROMPT=no Now restart the system and...

By default, when we are creating new user to Linux OS, all files from /etc/skel are copied to the new user's home directory. There are few files included in /etc/skel/ by default. * /etc/skel/.bash_logout * /etc/skel/.bashrc * /etc/skel/.profile * /etc/skel/.cshrc If you want to share some files, including rules and regulations to new users, simply add it...

Nginx quickly delivers static content with efficient use of system resources. It can deploy dynamic HTTP content on a network using FastCGI handlers for scripts, and can serve as a very capable software load balancer. Nginx uses an asynchronous event-driven approach to handling requests which provides more predictable performance under load, in contrast to the Apache HTTP server model that uses a threaded or...

hdparm provides  a command line interface to various kernel interfaces supported by the Linux SATA/PATA/SAS "libata" subsystem and  the  older IDE driver subsystem.  Many newer (2008 and later) USB drive enclosures now also support "SAT" (SCSI-ATA Command Translation) and therefore may also  work  with  hdparm. To see how your hard disk does compare: # hdparm -t...

“ViCompress HTTP proxy server reduces download time by gzip compressing text pages before sending them on the client. This results in faster download times, especially over slow network connections. ViCompress works with existing web servers and web browsers. All modern browsers (Internet Explorer, Firefox, Safari, Chrome) recognize gzip-encoded data, and will automatically decompress the data on the f...

  This article will guide you through the necessary steps to install ipw3945 wireless adapter on a CentOS / RHEL based distribution. Before we start, make sure that you have rpmforge repository configured. If you do not have, download it from here. # wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el5.rf.i386.rpm # rpm -ivh...

Google has recently released their very own DNS resolver with main goals of making web browsing faster and safer. Since Google's search engine already crawls the web on a daily basis and in the process resolves and caches DNS information, they wanted to make use of their technology to experiment with new ways of addressing some of the existing DNS challenges around performance and security. For advanced...

Nikto is a web server scanner tool, which performs comprehensive checking against web servers for multiple items, including over 3500 potentially dangerous files/CGIs, versions on over 700 servers, and version specific problems more than 200 servers. Nikto is built on LibWhisker and can run on any platform which has a Perl environment, and supports SSL, proxies, host authentication, IDS...

Dropbox is a Web-based file hosting service operated by Dropbox, Inc. which uses cloud computing to enable users to store and share files and folders with others across the Internet using file synchronization. It was founded in 2007 by MIT graduates Drew Houston and Arash Ferdowsi as a Y Combinator startup says Wikipedia.   To install DropBox on your system, download appropriate rpm for your...

Linux kernel has PC speaker bell driver called pcspkr.ko. It is responsible for generating beeps while users are working on Shell Prompts ( Both Virtual and GUI Terminals ). If you don't like it, simply remove driver from kernel. Login as a root and type the following command to unload the driver: # rmmod -v pcspkr Sample output: rmmod pcspkr, wait=no We...

If you run a dual-boot system with Linux and Windows, and reinstalling Windows XP after OS corrupt.  Windows XP will wipes over write grub entry or writing MBR sector. To recover GRUB, STEP 1: Boot off the Live CD enter into rescue mode, STEP 2: Open a Terminal and type in the following commands, noting that the first command will put you into the grub “prompt”, and ...

Backing up MySQL database is a very important system administration task, and should generally be run automatically from cron. We will use the mysqldump utility included with mysql to dump the contents of the database to a text file that can be easily restore. # mysqldump -h localhost -u root -p root_password DataBase > DB_name_Bkp.sql This will generate a text file containing ...

Do you want to Download your favorite you tube video in Linux? No problem! Here I have mentioned all steps to download you tube video using Linux Terminal.   Step 1: Install youtube-dl package by executing, On Ubuntu, $ sudo apt-get install youtube-dl On Fedora, RedHat, CentOS, # yum install youtube-dl -y Step 2: After having successfully installed youtube-dl, open a...

In computer terminology, a honeypot is a trap set to detect, deflect, or in some manner counteract attempts at unauthorized use of information systems. Generally it consists of a computer, data, or a network site that appears to be part of a network, but is actually isolated, (un)protected, and monitored, and which seems to contain information or a resource of value to attackers. STEP 1:...

Single-User mode is used for a system recovery. However, by default, no authentication is used if single-user mode is selected. This can be used to bypassing security on the server and gaining root access. To enable authentication for single-user mode, open the /etc/inittab, file: # vi /etc/inittab Add the following line to the...

YUM is an interactive, rpm based, package manager. It can automatically perform system updates, including dependency analysis and obsolete processing based on "repository" metadata. It can also perform installation of new packages, removal of old packages and perform queries on the installed and/or available packages among many other commands/services (see below). yum is similar to other high level package ...