Joshua Drake

(LinuxWorld) -- My last SysAdmin column was a modest attempt to bring some basic awareness on Linux 2.4 firewalling. This week we will continue on the security-focused path, bringing forth a plethora of knowledge for the uninitiated. The topic: PortSentry from Psionic Software. PortSentry is an easy-to-install application that is designed to assist a Linux user in their attempts to stop those cold-hearted crackers from breaching the mighty fortress that is your Linux machine. Specifically, PortSentry runs as a daemon on the protected host. When running, it listens to TCP/UDP ports that you specify. If it detects a port scan, it will block the scanning IP from connecting to your machine. Don't log in as root You should only log in as root when absolutely required. If you can use the su command with the -c flag to achieve your result, do so. If you are unsure on the s... (more)

DocBook can be a sysadmin's best friend

(LinuxWorld) -- Technical documentation is the savior and bane of every programmer and system administrator. On one hand, we need documentation as it helps us learn and understand what we need to accomplish. As long as we don't need to write it, we value documentation above all else. Most technical people I know don't like to write. They put Post-it Notes all over the place describing how to do this or that, and usually nothing more organized than a really big text file. The big-text-file system may work for some, but what happens when your not-so-technical manager comes to you... (more)

10 minutes to an iptables-based Linux firewall

(LinuxWorld) -- As I write this column, the world suffers infestation by yet another Internet worm, and again the worms are intended to attack Microsoft-based machines. Fortunately for my company, we don't run any Microsoft-based machines, but the Nimda worm still affects us.   Nimda eats our bandwidth since other companies sharing our subnet are running infectious Windows 98, NT, and 2000 machines. These diseased, ill-maintained beasts from the land of insufficient light are now trying to infest our stable, secure, long running, easy-to-use, well-behaved Linux machines. (Can ... (more)

The kernel of pain

(LinuxWorld) -- Let's start from the beginning. In July 2001, I was responsible for upgrading a customer's server from Red Hat 6.2 to Mandrake 8.0. The machine was built from scratch, and Mandrake was installed onto a freshly formatted RAID 5 array. We then migrated the Red Hat 6.2 applications to the new machine. After a little configuration, the machine seemed to run fine. We successfully migrated the entire system in less than five hours. Considering this was a large-scale server, that was quite a feat and was certainly welcomed by our paying customer. However, after about a... (more)

Zelerate's AllCommerce targets e-business

I have had my eye on Zelerate (formerly OpenSales) since I saw the company's booth at the LinuxWorld Expo last August. So when LinuxWorld.com asked me to review Zelerate's AllCommerce product, I was happy to oblige. I have developed shopping carts in the past, but they have always been for a specific product line, and therefore not very flexible. I prefer to use PHP and PostgreSQL. The Zelerate AllCommerce software can create a flexible, database-independent solution, using only Perl. AllCommerce provides more than just a shopping cart; it offers inventory control, order tracking, ... (more)