20 Examples: Make Sure Unix / Linux Configuration Files Are Free From Syntax Errors

Posted on in Categories Howto, Linux, Sys admin, Tips, UNIX last updated February 27, 2016

In Linux and UNIX system services are configured using various text files located in /etc/ or /usr/local/etc/ directory tree. A typical server system could have dozens of configuration files.You can check your configuration files for syntax errors without starting the server and validate all settings. In some cases, it is possible to to check the sanity of the specific data (such as keys) or directories (such as /var/lib/cache/). Text files are easier to manage remotely. You can use ssh and a text editor. If there is an error in configuration, the server may not start. It may result in a disaster. This post explains how to quickly how to find out a syntax error for popular servers and test configuration file for syntax errors.

HowTo: Wake Up Computers Using Linux Command [ Wake-on-LAN ( WOL ) ]

Posted on in Categories Debian Linux, Linux, Networking, Ubuntu Linux last updated April 3, 2012

Wake-on-LAN (WOL) is an Ethernet networking standard that allows a server to be turned on by a network message. You need to send ‘magic packets’ to wake-on-lan enabled ethernet adapters and motherboards, in order to switch on the called systems. Make sure you connect the NIC (eth0 or eth1) with the motherboard, and enable the WOL function in the BIOS. This is a quick guide to enable WOL under RHEL / Fedora / CentOS / Debian / Ubuntu Linux.

Video: Who Writes Linux Kernel?

Posted on in Categories Linux last updated April 3, 2012

Linux kernel is the most prominent examples of free and open source software. The Linux kernel has received contributions from thousands of programmers and companies around the world. This professional video from the Linux foundation provides a quick insight into Linux building procedure. This is a powerful and inspiring story of how Linux has become a volunteer-driven phenomenon.

Adobe Flash v11.2 and Above Will Only Be Available For Chrome Browser on Linux

Posted on in Categories Linux, Mozilla last updated June 6, 2012

Adobe announced that the Flash player for Linux will only be available for Google Chrome browser on Linux and has announced their plans to abandon future updates of Flash player for Linux. From the blog post:

For Flash Player releases after 11.2, the Flash Player browser plugin for Linux will only be available via the “Pepper” API as part of the Google Chrome browser distribution and will no longer be available as a direct download from Adobe. Adobe will continue to provide security updates to non-Pepper distributions of Flash Player 11.2 on Linux for five years from its release.

30 Best Sources For Linux / *BSD / Unix Documentation On the Web

Posted on in Categories Debian Linux, FreeBSD, HP-UX, Linux, Linux distribution, OpenBSD, RedHat/Fedora Linux, Ubuntu Linux, UNIX last updated February 23, 2012

Man pages are written by sys-admin and developers for IT techs, and are intended more as a reference than as a how to. Man pages are very useful for people who are already familiar with Linux, Unix, and BSD operating systems. Use man pages when you just need to know the syntax for particular commands or configuration file, but they are not helpful for new Linux users. Man pages are not good for learning something new for the first time. Here are thirty best documentation sites on the web for learning Linux and Unix like operating systems.

Linux: 20 Iptables Examples For New SysAdmins

Posted on in Categories Iptables, Linux, Linux distribution, Linux Embedded devices, Linux laptop last updated January 21, 2016

Linux comes with a host based firewall called Netfilter. According to the official project site:

netfilter is a set of hooks inside the Linux kernel that allows kernel modules to register callback functions with the network stack. A registered callback function is then called back for every packet that traverses the respective hook within the network stack.

This Linux based firewall is controlled by the program called iptables to handles filtering for IPv4, and ip6tables handles filtering for IPv6. I strongly recommend that you first read our quick tutorial that explains how to configure a host-based firewall called Netfilter (iptables) under CentOS / RHEL / Fedora / Redhat Enterprise Linux. This post list most common iptables solutions required by a new Linux user to secure his or her Linux operating system from intruders.