Network Fundamentals

Spanning Tree and Switches are a lot like the Highlander – “there can be only one”  (root bridge in your spanning tree).  The process of electing a root bridge is very similar to Highlander in that switches will battle it out until one bridge is the root.  And all designated …

As your network begins to grow you start to see a need to logically separate different parts of your network into different broadcast domains. But what is a broadcast domains and how is it different from a collision domains? And how do I get two different broadcast domains to talk …

Collision Domains are layer 2 segments where computers can communicate over ethernet.  But what happens when your layer 2 ethernet segment gets too noisy and packets start colliding. Your network performance goes down the toilet and you starts getting complaints from your users.  Not a good thing! Welcome to the …

Network Routing Protocols – IGRP, EIGRP, OSPF, ISIS, BGP Overview of Routing Protocols The purpose of routing protocols is to learn of available routes that exist on the enterprise network, build routing tables and make routing decisions. Some of the most common routing protocols include RIP, IGRP, EIGRP, OSPF, IS-IS …

Authentication, Authorization, and Accounting… Otherwise Known as AAA (triple A).  Most people who have had to implement AAA on a router or switch probably know very little about the commands they copy to the router config.  Most simply grab the AAA configs from another working router or switch and be …

Many engineers (at one time myself too) believe they understand wild card masks. If you ask someone they will most likely tell you that a wild card mask is just the opposite or reverse of a subnet mask. Unfortunately this isn’t quite correct. Yes, at first glance a wild card …

Today I’m going to get back to basics and discuss the 7 layer OSI reference model and how it applies to networking.  Most experienced network engineers know the OSI model all to well and most if not all certifications will expect you to know it. So lets unwrap this 7 …