IT Knowledgebase Articles

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…

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….

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

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,…

In this article, we will take a step further in securing our Cisco router by using a local username / password database in the Cisco IOS. Thus, a user must know a username AND password to be granted access to the Cisco IOS. Let’s see how this is done. Local Authentication The most basic level…

Why is your router’s Ethernet interface called Ethernet0/0 on one router but Ethernet 3/0 on another router? Where do these names come from? This article will explain how Cisco router interfaces get their names. Where do Router Interfaces get their names? Router interfaces get their names when the router boots.  A “device discovery” takes place…

Many of us use switches every day but never really think about how they work. Whether you are studying to become a CCNA or just want to learn more about how a switch really functions, this article is for you. Hubs vs. Switches Prior to switches, Hubs were the standard for connecting devices on a…

In our previous series on Cisco IOS Access-lists Part 1 and Part 2 , we covered all the basics of ACL’s and went through a real-world example. In the past, it was not possible to edit an ACL. Now, the impossible is possible with IOS 12.2 or later. In this article, you’ll learn how you…

If someone were to look at your router’s configuration, could they understand what the real purpose of the network connections were, who they connect to, and what to do if the interface is down? If you answered no, then you need to look at using router interface descriptions. What is a router interface description? Router…

Would you like to host a web server or e-mail server on your Internet connection, but don’t want to pay for a static IP address? Dynamic DNS (DDNS) is here to allow you to host that website while still using a dynamic IP address. Previously, this was only available as an executable computer program, or…