Book Image

CCNA Routing and Switching 200-125 Certification Guide

By : Lazaro (Laz) Diaz
Book Image

CCNA Routing and Switching 200-125 Certification Guide

By: Lazaro (Laz) Diaz

Overview of this book

Cisco Certified Network Associate (CCNA) Routing and Switching is one of the most important qualifications for keeping your networking skills up to date. CCNA Routing and Switching 200-125 Certification Guide covers topics included in the latest CCNA exam, along with review and practice questions. This guide introduces you to the structure of IPv4 and IPv6 addresses and examines in detail the creation of IP networks and sub-networks and how to assign addresses in the network. You will then move on to understanding how to configure, verify, and troubleshoot layer 2 and layer 3 protocols. In addition to this, you will discover the functionality, configuration, and troubleshooting of DHCPv4. Combined with router and router simulation practice, this certification guide will help you cover everything you need to know in order to pass the CCNA Routing and Switching 200-125 exam. By the end of this book, you will explore security best practices, as well as get familiar with the protocols that a network administrator can use to monitor the network.
Table of Contents (24 chapters)
4
Subnetting in IPv4
21
Mock Test Questions
22
Assessments

A brief history of NAT

NAT was set up simply to slow down the depletion of public IPv4 addresses. When the commercialization of the internet started, we found ourselves running out of public assigned IP addresses. No one could have imagined that 4.2 billion addresses were going to fall short of the mark.

So, the concept of NAT was introduced, with its purpose of taking a private IPv4 address and translating it into a public IPv4 address, so that it could go onto the internet and allow users to do whatever they need to do.

If you want to get specific as to what NAT can help us do, besides go play online video games, here are some points that you should keep in mind:

  • NAT enables you to connect to the internet and your end devices have only private IP addresses
  • When you change to a new ISP, you do not need to change your internal addressing
  • NAT helps if you are bringing networks...