If SSH is the Swiss Army knife of the system administration world, Nmap is a box of dynamite. It's really easy to misuse dynamite and blow your foot off, but it's also a very powerful tool that can do jobs that are impossible without it. more>>
1999 was a crazy year for business on the Internet, and for Linux. It was when Red Hat went public, with a record valuation, and VA Linux followed with a bigger one. Both were cases in point of the dot-com boom, a speculative bubble inflated by huge expectations of what the Internet would mean for business. more>> […]
In recent years, there has been a trend in which data centers have been opting for commodity hardware and software over proprietary solutions. Why shouldn't they? It offers extremely low costs and the flexibility to build an ecosystem the way it is preferred. The only limitation is the extent of the administrator's imagination. more>> […]
I've always been a fan of putting aftermarket firmware on consumer-grade routers. Whether it's DD-WRT, Tomato, OpenWRT or whatever your favorite flavor of "better than stock" firmware might be, it just makes economic sense. Unfortunately, my routing needs have surpassed my trusty Linksys router. more>> […]
Is it weird to say that DNS is my favorite protocol? Because DNS is my favorite protocol. There's something about the simplicity of UDP packets combined with the power of a service that the entire Internet relies on that grabs my interest. Through the years, I've been impressed with just how few resources you need to run a modest DNS infrastructure […]
In my last article, we began an exploration of date math by validating a given date specified by the user, then explored how GNU date offers some slick math capabilities, but has some inherent limitations, the most notable of which is that it isn't on 100% of all Linux and UNIX systems. more>> […]
For some time now, there has been tremendous growth in the world of Web applications. It's quite amazing to see what you can do just via a Web browser—not only can you buy just about anything, but also a growing number of sites offer "software as a service", often abbreviated as SaaS. The idea is that in exchange for a monthly service fee, you […]
I work at a university, and one of our faculty members often repeats to me, "Software needs to be like a rock; it needs to be that easy to use." And, she's right. Because if software is too hard to use, no one will want to use it. more>>
I've looked at specialty distributions that were created for engineers and biologists in previous articles, but these aren't the only scientific disciplines that have their own distributions. So in this article, I introduce a distribution created specifically for astronomers, called Distro Astro. more>> […]
I'm a new Ubuntu 12.04/14.04 server user. How do I install and use memcached on an Ubuntu Linux 14.04 LTS server? How can I my apps written in PHP or Python can use memcached on an Ubuntu LTS server?Read answer to: "Ubuntu Linux 12.04/14.04 LTS Install Memcached Server For Python and PHP Apps"
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 e […]
I recently switched from MS-Windows server to a FreeBSD Unix server. How can I see list of mounted file systems on a FreeBSD based Unix server using command line options?Read answer to: "FreeBSD Unix Show Mounted File Systems"
I'm a new Ubuntu Linux user. In Linux, Apple OS X or Unix-like systems, how do I reissue or repeat a long command without retying it?Read answer to: "Bash: Reissue And Repeat A Long Command Without Retyping It on a Linux, OS X & Unix"
I need to tunnel X Window securely over SSH bases session so that I run X program on my remote Linux/Unix server/workstation and get back display to my Apple Macbook pro laptop. I tried the ssh -X user@server1 and ssh -Y user@server2 commands on both OS X Mountain Lion and Apple OS X Mavericks/Yosemite. But, I am unable to use the ssh command with X11. How d […]
I have a Linux DD-WRT router DHCP server running on my network. How can I force my FreeBSD based dhcp client to get a new lease from this Linux based router? What is the command in FreeBSD equivalent to Windows' "ipconfig /renew" command?Read answer to: "FreeBSD Force DHCP Client (dhclient) to Renew IP Address To Get A New Lease" […]
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?Read answer to: "How To Stress Test CPU and Memory (VM) On a Linux and Unix With Stress-ng"
The GHOST (CVE-2015-0235) is serious network function vulnerability in Glibc. How do I check and test if a my Linux based server is secure using command line options?Read answer to: "Glibc: GHOST Vulnerability Test To See If a Linux Sever Is Secure"
A very serious security problem has been found in the GNU C Library (Glibc) called GHOST. How can I fix GHOST vulnerability and protect my Linux server against the attack? How do I verify that my server has been fixed against the Glibc GHOST vulnerability?Read answer to: "How To Patch and Protect Linux Server Against the Glibc GHOST Vulnerability # CVE- […]
I need additional swap space to improve my FreeBSD Unix server/desktop performance. How do I add a swap file to FreeBSD system using command line options without creating a new partitions? How do I encrypt swap space on a FreeBSD Unix server for security purpose?Read answer to: "How To Add Swap on FreeBSD Unix Systems"