Book Image

Implementing and Administering Cisco Solutions: 200-301 CCNA Exam Guide

By : Glen D. Singh
Book Image

Implementing and Administering Cisco Solutions: 200-301 CCNA Exam Guide

By: Glen D. Singh

Overview of this book

In the dynamic technology landscape, staying on top of the latest technology trends is a must, especially if you want to build a career in network administration. Achieving CCNA 200-301 certification will validate your knowledge of networking concepts, and this book will help you to do just that. This exam guide focuses on the fundamentals to help you gain a high-level understanding of networking, security, IP connectivity, IP services, programmability, and automation. Starting with the functions of various networking components, you’ll discover how they are used to build and improve an enterprise network. You’ll then delve into configuring networking devices using a command-line interface (CLI) to provide network access, services, security, connectivity, and management. The book covers important aspects of network engineering using a variety of hands-on labs and real-world scenarios that will help you gain essential practical skills. As you make progress, this CCNA certification study guide will help you get to grips with the solutions and technologies that you need to implement and administer a broad range of modern networks and IT infrastructures. By the end of this book, you’ll have gained the confidence to pass the Cisco CCNA 200-301 exam on the first attempt and be well-versed in a variety of network administration and security engineering solutions.
Table of Contents (26 chapters)
1
Section 1: Network Fundamentals
6
Section 2: Network Access
9
Section 3: IP Connectivity
12
Section 4: IP Services
15
Section 5: Security Fundamentals
20
Section 6: Automation and Programmability
22
Chapter 16: Mock Exam 1
23
Chapter 17: Mock Exam 2

Understanding first hop redundancy

Let's imagine that, within your organization, each device is configured to use a specific IP address as its default gateway to the internet. What if that IP address or device goes offline? How will your client devices reach the internet?

The following diagram shows the default gateway going down, thus preventing clients from reaching the internet:

Figure 8.54 – Default gateway goes offline

You may be thinking, we can replace the router with another and apply the same configurations to it and our internet connectivity will be restored. This is a workable solution, but it's not too efficient because it's a reactive solution and requires too many interventions.

What if we could implement redundancy on the default gateway to ensure that, if the main router goes down, there's another device that will act as the new default gateway, without us having to change the default gateway's IP address...