Practical Networking .net

VLANs — Index

The following index of articles all cover various aspects of Virtual Local Area Networks, or VLANs. They are listed here in one place to make it easier to find if you are interested in learning more about VLANs. This handy shortlink has been created which will always take you to this page: Practical Networking […]


FLSM and VLSM – Part 2

I’ve just completed Part 2 of the VLSM and FLSM extensions of the Subnetting Mastery video series. The series now, more than ever, covers everything anyone would ever need to know about Subnetting. The series runs you through an example VLSM (Variable Length Subnet Mask) problem. You are given the network and tasked to […]


FLSM and VLSM – Part 1

After many requests to extend the Subnetting Mastery video series, I am adding an appendix which will cover Fixed Length Subnet Masks (FLSM) and Variable Length Subnet Masks (VLSM). This is Part 1, which teaches how to answer questions of this variety: If you start with a /18, what size sub-network would you need to […]


Voice VLAN – Auxiliary VLAN

The terms Voice VLAN or Auxiliary VLAN typically mean the same thing: They are a feature which allows an access port — which normally only accepts untagged traffic for a single VLAN — to also accept tagged traffic for a second VLAN. But that is merely the “what”, and if you were simply looking for […]


Converged Network

In the early days of Networking, a computer network was meant to carry only data traffic. As time went on, VOIP, or Voice-Over-IP technologies were invented, computer networks had to be designed to also carry Voice traffic. When a single network fabric is carrying both Data traffic and Voice traffic, it is referred to as […]


What is the Native VLAN?

The Native VLAN is an oft confused concept, though it needn’t be. This video will explain what the Native VLAN is and how it affects traffic on a wire. Summary An Access port (or “untagged port” in the non Cisco world) is a switch port which carries traffic for only one VLAN. A Trunk port […]


Subnetting Mastery

Lately I’ve been working on a Subnetting Mastery video series. The goal is take someone with little to no exposure to subnetting and make them a subnetting pro. I’m happy to announce that the video series is finally complete! If anyone is working through or trying to learn subnetting, this is the video series for […]


Cisco ASA NAT – Configuration Guide

This article provides all the information you need to understand and configure NAT on Cisco ASA and Cisco ASA-X Firewalls. There are  four possible methods of address translation, and each were defined in the Network Address Translation article series: Static NAT, Static PAT, Dynamic PAT, Dynamic NAT. This article assumes prior knowledge of each of […]