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 […]
The Cloonix development team recently released a major update to the Cloonix network simulator. Cloonix version 28 makes major changes to the infrastructure of Cloonix. It changes the installation procedure, the location of Cloonix files on your computer, and the names of the commands used to start and administer Cloonix. Cloonix version 28 also makes
I need to determine the maximum number of KVM virtual machines that can run on an average laptop computer. Unfortunately, I cannot find authoritative information about the maximum number of KVM virtual machines that can run on a host computer. Most information I could find about KVM limits does not publish absolute limits but, instead,
In this post, I will show how to set up data capture in the GNS3 network simulator when using network devices that are emulated by VirtualBox or QEMU virtual machines. The GNS3 network simulator makes it easy for users to capture and view data passing across the interfaces of devices running in a GNS3 network
GNS3 1.3 will create and manage VirtualBox virtual machine linked clones from within the GNS3 user interface. This simplifies the process of setting up VirtualBox virtual machines in GNS3, which makes GNS3 easier to use for studying the operation of open-source routers, switches, and hosts in network simulation scenarios. In this post, I will show
When network engineers are learning the concepts of software defined networking and SDN controllers, they may want to experiment with SDN network scenarios before learning to write programs to be used by the SDN controllers. POX is a simple-to-use SDN controller that is bundled with the Mininet SDN network emulator and is used in education
When testing SDN functions in the Mininet network emulator and viewing captured OpenFlow messages in a packet analyzer such as Wireshark, it is difficult to identify which SDN switch is the source or destination of each captured message. The only reliable way to identify which SDN switch sent or received an OpenFlow message is to
The IMUNES open-source network simulator can now be installed on and run on Linux. Previously, IMUNES was available only for the FreeBSD operating system. The Linux version of IMUNES is ready to be used and can set up and run network emulation scenarios. It does not yet have all the features offered in the FreeBSD
In 2014, the GNS3 development team launched a successful Kickstarter crowdfunding campaign to support development of a major new release, version 1.0, which was released in October that same year. I was happy to support the Kickstarter campaign and now I am finally getting around to taking a look at the new version of GNS3.