Archives For Publishing

I recently purchased a used Lenovo Thinkpad T420 laptop to replace the Lenovo Thinkpad T400 I was previously using as my main platform for researching open-source network simulators and emulators. The T420 is a five-year old product but it offers all the ports and performance I need. Because it is well past its depreciation curve, anyone can purchase a used T420 for a very low price.


I wanted a computer that supports high-resolution external monitors so it required a DisplayPort output. I also wanted to expand the number of VMs I can run concurrently with adequate performance so I needed a processor that supports HyperThreading. I wanted to switch to the Ubuntu Linux distribution and the Ubuntu Unity desktop environment needs just a bit more processing power to run smoothly. The Lenovo Thinkpad T420 meets all these requirements.

Continue reading to learn more about the Lenovo Thinkpad T420, another excellent and inexpensive Linux platform.

Continue Reading…

When writing a blog post about a technical topic, I often capture a lot of screen shots that I need to edit before adding them to my blog article. Usually I want to add a border around each image and I sometimes want to reduce the size of images that are too large. I want to do this quickly and easily so I use ImageMagick, an open-source command line image editor.


ImageMagick is a powerful image manipulation tool with an intimidatingly large set of options and subcommands. However, most bloggers will use only a few simple options. In this post, I will show how to install and use ImageMagick to perform the simple image conversions bloggers typically need. I will show how this can be done on each of the major operating systems: Linux, Windows, and Mac OS X.

Continue Reading…

Blog status report 2014

August 7, 2014

The occasion of my fiftieth post is a good milestone to pause and look back on the two years since I started blogging about open-source routing and network simulation. I will review the blog’s performance statistics and reflect on why I started this blog and what I want to do next.

50th post stats

The chart above shows the blog traffic over the past two years, starting in August 2012. In the first year I thought I would reach only a small audience but, as I posted more content, more users found my blog. In the past twelve months, 29,500 unique users visited this blog. Traffic grew steadily almost every month in the past year.

Continue Reading…

Image used is from

Image used is from

When I started researching open-source routing and networking software, I ran the open-source Linux operating system on a virtual machine running on my Apple iMac computer. When I wanted to experiment with virtualization technologies such as KVM, which will not work inside a virtual machine, I set up my iMac to dual-boot Linux and Mac OS X.

Eventually, I wanted a second computer on which I could frequently install and re-install different distributions of Linux without worrying if I would cause problems on the iMac, which is also used by the rest of my family.

I needed to buy a computer specifically for my research project. I wanted to get a good computer at a very low price. Read on to learn about the Lenovo T400 laptop computer, an excellent and inexpensive Linux platform.

Continue Reading…

Google Webmaster Tools

March 5, 2014

Recently, Google temporarily dropped my blog from its search results. Since over 75% of my traffic comes from first-time users who find the site through search results, this effectively caused a two-day “outage” for my site.

As I tried to understand why my blog was not findable in Google, I realized that it would have been helpful to have Google Webmaster Tools set up on my hosted web site.

This post describes how to set up Google Webmaster Tools for a blog hosted on a remote server managed by a service provider, such as bluehost.

Continue Reading…