Category: Networking

How to run Cisco router as a virtual machine?

Introduction In this post we will learn how to install and run Cisco router as a virtual machine. Cisco has a special product called CSR (Cloud Services Router) 1000v for deploying routers as virtual machines. You can use these VMs for testing and learning purposes. Cisco supports all popular cloud and virtualization platforms, but I

Port Forwarding on Fortigate

Introduction In this post we will configure port forwarding on a Fortigate firewall running FortiOS 5.4. What is Port Forwarding? Port forwarding is a feature on the routers/firewalls that allows devices behind the NAT to be accessed by external devices. In other words, if you want anyone on the Internet to access a service (e.g.

Mininet Tutorial

What is Mininet? Mininet is a software that emulates virtual network environment with OpenFlow support. It is great for learning, prototyping and testing SDN features and applications.   How to install Mininet? There are several ways you can install Mininet. The easiest and recommended one is to go to and download the image for your

Tcpdump command examples.

Introduction This post is about tcpdump – packet analyzer that comes preinstalled with any modern Linux distribution. tcpdump allows us to capture packets and either display them in real time or save them to a file for later analysis. We will look at several examples of using tcpdump to learn which options it has and

How to configure DHCP server on Aruba switches

The configuration of DHCP server on Aruba switches is pretty similar to the configuration of DHCP server on Cisco switches, except that Aruba switches require  dhcp-server explicitly enabled on an interface. First, we have to configure L3 interface on our switch, the snippet below shows how to assign IP address( to VLAN 1. Now that