A rootkit is a program designed to take fundamental control of a computer system, without authorization by the system’s owners and legitimate managers.

Most rootkits use the power of the kernel to hide themselves, they are only visible from within the kernel. How do I detect rootkits under CentOS or Debian Linux server?

Linux Detecting / Checking Rootkits with Chkrootkit and rkhunter Software

Internet SCSI (iSCSI) is a network protocol that allows you to use of the SCSI protocol over TCP/IP networks. It is good alternative to Fibre Channel-based SANs. You can easily manage, mount and format iSCSI Volume under Linux. It allows access to SAN storage over Ethernet. Open-iSCSI project is a high-performance, transport independent, multi-platform implementation of iSCSI. Open-iSCSI is partitioned into user and kernel parts.

The iscsi package provides the server daemon for the iSCSI protocol, as well as the utility programs used to manage it. iSCSI is a protocol for distributed disk access using SCSI commands sent over Internet Protocol networks. This package is available under Redhat Enterprise Linux / CentOS / Fedora Linux and can be installed using yum / apt-get command.

netcat utility (nc command) considered as TCP/IP swiss army knife. It reads and writes data across network connections, using TCP or UDP protocol. It is designed to be a reliable “back-end” tool that can be used directly or easily driven by other programs and scripts. At the same time, it is a feature-rich network debugging and exploration tool, since it can create almost any kind of connection you would need and has several interesting built-in capabilities.

This howto explain migrating data between two server hard drives using netcat over a network. It is very easy to copy complete drive image from one server to another.

With this tip you will be able to work from home using VPN and that too from Linux / FreeBSD system for the proprietary Microsoft Point-to-Point vpn server.

Different organization uses different VPN connection options such as SSL, PPTP or IPSEC. When you need to access corporate network and its services, you need to login using VPN.

The Point-to-Point Tunneling Protocol (PPTP) is a method for implementing virtual private networks. It works on Data link layer (#2 layer) on TCP/IP model. Personally I prefer IPSEC. PPTP Client is a Linux, FreeBSD, NetBSD and OpenBSD client for the proprietary Microsoft Point-to-Point Tunneling Protocol, PPTP. Allows connection to a PPTP based Virtual Private Network (VPN) as used by employers and some cable and ADSL internet service providers.

Most of us work with a shell prompt. By default most Linux distro displays hostname and current working directory as a prompt. You can easily customize your prompt to display information important to you. You change look and feel by adding colors. In this small howto I will explain howto setup:

a] Howto customizing a bash shell to get a good looking prompt
b] Configure the appearance of the terminal.
c] Apply themes using bashish
d] Howto pimp out your shell prompt

How do I set the shell prompt in Linux Terminal?