Advanced ( Expert) Linux / Unix System Administrator

These tutorials assumes that you have rock solid understanding of Unix like operating systems and very comfortable with most aspects of the Unix/Linux such as networking/distributed computing environments,routing, firewalls, servers, client/server programming, and the design of consistent network-wide filesystems, load-balancers, security and much more. ( rss feed )

I work from a small office/home office and I need to set up an IPSec site-to-site VPN between a Cisco/OpeNBSD IPSec-enabled gateway and firewall running PFSense. How do I configure the VPN tunnel so that I can access remote subnet and servers behiend a Cisco firewall/router securely? How do I setup a tunnel mode configuration which will provide you with an encrypted site-to-site network, allowing networks at multiple remote locations to be able to securely communicate using my PFSense located in my SOHO?


I want test my Linux, OpenBSD, FreeBSD and Unix-like server entirely for high load and monitoring the health under stress. How can I stress out my CPU, memory, I/O, and disk stress and more with stress test tool on a Linux or Unix-like systems?


I‘m a new Linux / Unix system user. How can I set encrypted tunnel between my desktop/laptop computer and server in a remote data center to bypass the limits in a network? How do I create a reverse SSH tunnel on Unix-like systems?


chroot command

I am a new Linux and Unix user. How do I change the root directory of a command? How do I change the root directory of a process such as web-server using a chroot command to isolate file system? How do I use a chroot to recover password or fix the damaged Linux/Unix based environment?


I run a web-server and I would like to log packets with un-routable source addresses on Linux operating system. How can I log spoofed packets on Debian / Ubuntu / CentOS / RHEL / Linux based server? How can I log a Martian packet (packet from Mars) on Linux operating systems?


How do I setup and manage a virtualized environment with Kernel based Virtual Machine (KVM) in CentOS or Red Hat Enterpise Linux version 6 server on IBM server? Can you provide step-by-step commands of how to install and manage Virtual Machines (VMs) on a physical server using KVM for RHEL/CentOS version 6.4?


I operate a small web site on Cloud server powered by CentOS Linux v6.4. I would like to encrypt my site’s information and create a more secure connection. How do I create a self-signed SSL certificate on Nginx for CentOS/Fedora or Red Hat Enterprise Linux based server?