Practical Networking .net
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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 […]

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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 […]

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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 […]

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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 […]

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Cisco NAT Configuration – IOS Router

In this article, we will illustrate the Cisco NAT configuration on IOS Routers. This is a follow up article to the Network Address Translation article series which thoroughly covered the operation of NAT and answers the questions “What is NAT?” and “How does NAT work?“. There are only four types of network address translation: Static NAT, Static PAT, […]

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Cisco NAT Terminology

Cisco has created some NAT terminology which explicitly refer to the IP addresses and/or ports involved in Network Address Translation (NAT). While discussing the addresses involved in a NAT, using the terms like “Source” and “Destination” are common. However, using such terms can create some ambiguity. Specifically, the terms “Source” and “Destination” can create confusion […]

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Network Address Translation (NAT)

Every device on the Internet has an IP address. The IP address serves as the device’s identification – much like how a phone number identifies a particular phone. When devices communicate on the Internet, they are sending data from their IP address to the IP address of their intended destination. Sometimes, while data is en […]

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NAT Terminology Disambiguation

If you’ve made it here, then at this point you should have a solid understanding of each of the four types of translation that can exist: Static NAT, Static PAT, Dynamic PAT, and Dynamic NAT. Moreover, you have an understanding of Policy NAT and Twice NAT, which are simply two different ways of implementing the […]