David Davis

The ping command is irreplaceable when it comes to troubleshooting. At some point, you will undoubtedly use this command to solve a networking problem. But how do you properly use this command in the Cisco IOS? There is more to it than you might think. What Are The Basics of Ping? The ping command works…

In a previous article, we explained the OSI model and how it works. In that article, we went over how the OSI model is a standard theoretical model for how networking hardware, software, protocols work together. What we didn’t discuss in that article is how the OSI model can help you in your day to…

Maybe you have a new router or you want to verify that you have security properly configured on your existing router. Either way, password security is critical to properly securing your Cisco router. So let’s get started configuring passwords on your Cisco router. Types of Cisco Router Passwords When it comes to basic password security,…

Lost the password to your Cisco switch? David Davis walks you through how to recover that password (and your sanity).

As a network administrator, you must be able to configure your routers to route traffic across the network. Static routes are commonly used on routers to accomplish this. For a network admin, knowing how to use a static route is a requirement. Let’s learn about static routes, and how to properly use them. Static vs….

A Cisco IOS Access-List (ACL) is used to specify network traffic. Once you specify traffic with an ACL, you can then do a variety of things with it. For example, you could allow it, deny it, limit it, or use it to restrict routing updates. In this article, we will learn the basics of Cisco…

In Part 1 of this article, we explained how access-lists work. In this article, we’ll take a sample network and explain how to create and apply an access-list. Remember that an Access-List (ACL) is used to specify network traffic. Once you specify traffic with an ACL, you can then do a variety of things with…

Most Cisco devices do not have a graphical Web-based interface by default.  You must configure them from the command line using the serial-based console port on the switch or router.  While there are a variety of serial terminal emulation programs available, most people use HyperTerminal to do this because it is included free with Windows. …

VMware ESX server is an amazing and complex product. It combines a Linux Service console with the power to run multiple virtual machine operating systems, all on the same server. There are a number of ways to administer ESX. Perhaps you are considering VMware ESX server or maybe you have it installed but want to…

Have you ever made a change to your VMware ESX Server Network configuration using the Virtual Infrastructure (VI) Client and then lost communications with the server? If you had to go to the ESX Service console to troubleshoot the virtual network configuration, would you know the commands to do it? In this article, you will…