Security Control Using a Switch

Posted by in Security+ | 0 comments

Understanding basic network devices such as using a switch is an important topic for the Security+ exam.  This post should help.

For example, can you answer this question?

Q. Your organization has several switches used within the network. You need to implement a security control to secure the switch from physical access. What should you do?

A. Disable unused ports.

B. Implement an implicit deny rule.

C. Disable STP.

D. Enable SSH.

More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.

Security+ Practice Test Questions

SY0-501 Practice Test Questions 

Over 300 realistic Security+ practice test questions

All questions include explanations so you'll know why the correct answers are correct,

and why the incorrect answers are incorrect.

Pass the Security+ Exam

the First Time You Take It

Multiple quiz formats to let you use these questions based on the way you learn.
  • Learn mode - randomized. View each of the questions in random order. Learn mode allows you to keep selecting answers until you select the correct answer. Once you select the correct answer, you'll see the explanation. Click here to see how learn mode works.
  • Learn mode - not randomized. View each of the questions in the same order. Use this if you want to make sure that you see all of the questions. Learn mode allows you to keep selecting answers until you select the correct answer. Once you select the correct answer, you'll see the explanation. Click here to see how learn mode works.
  • Test mode - randomized. View each of the questions in random order. In test mode, you can only see the correct answers and explanations after you complete the test. Click here to see how test mode works.
  • Test mode - not randomized. View each of the questions in the same order. In test mode, you can only see the correct answers and explanations after you complete the test. Click here to see how test mode works.
  • Test mode - 75 random questions. View 75 random questions from the full test bank similar to how the Security+ exam has a potential maximum of 75 multiple choice questions. In test mode, you can only see the correct answers and explanations after you complete the test. Click here to see how test mode works.

Get the full bank of SY0-501 Practice Test Questions Here

 SY0-501 Practice Test Questions


INCLUDES QUESTIONS TO HELP YOU PREPARE

FOR THE NEW PERFORMANCE BASED QUESTIONS 

Bonus - Performance Based Questions

Three sets of performance-based questions including over 30 questions. These questions show you what you can expect in the live exam. They include drag and drop, matching, sorting, and fill in the blank questions. See a demo here.

Bonus - Extra Practice Test Questions

New multiple-choice questions in the extra test bank. Questions are added occasionally. You can see what has been added recently here.

Get the full bank of Security+ (SYO-501) Practice Test Questions Here

Get the full bank of Security+ Practice Test Questions

Click here if you're looking for SY0-501 Full Study Package

How a Switch Works

A switch has the ability to learn which computers are attached to each of its physical ports. It then uses this knowledge to create internal switched connections when two computers communicate with each other.

Consider the following figure. When the switch turns on, it starts out without any knowledge other than knowing it has four physical ports. Imagine that the first traffic is the beginning of a TCP/IP conversation between Lisa’s computer and Homer’s computer.

Switch

Switch

When Lisa’s computer sends the first packet, it includes the MAC address of the destination computer. However, because the switch doesn’t know which port Homer’s computer is connected to, it forwards this first packet to all the ports on the switch.

Included in that first packet is the MAC address of Lisa’s computer. The switch logs this information into an internal table. It then directs any future traffic addressed to Lisa’s MAC address to port 1, and port 1 only.

When Homer’s computer receives the packet, it responds. Embedded in this return packet is the MAC address of Homer’s computer. The switch captures Homer’s MAC address and logs it with port 4 in the internal table. From here on, any unicast traffic between Lisa’s and Homer’s computers is internally switched. Switches will internally switch unicast traffic. However, they pass broadcast traffic to all ports.

CompTIA Security+ Study Guide

The 501 Version of the Study Guide

The CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide is an update to the top-selling SY0-201, SY0-301, and SY0-401 study guides, which have helped thousands of readers pass the exam the first time they took it.  It includes the same elements readers raved about in the previous three versions.

Each of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.

You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.



Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:

  • A 75 question pre-test
  • A 75 question post-test
  • Practice test questions at the end of every chapter.

Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.

If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-501 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.

Kindle edition also available.

Security Benefit of a Switch

What you really need to know is why basic networking relevant in security. If an attacker installed a sniffer on a computer attached to another port (such as port 3 in the figure above), the sniffer would not capture unicast traffic going through the switch to other ports. If Lisa and Homer are exchanging data on ports 1 and 4, none of the traffic reaches port 3. The sniffer can’t capture traffic that doesn’t reach the port.

In contrast, if the computers were connected via a hub, unicast traffic goes to all hub ports and the attacker could capture it. This is the main security reason why organizations replace hubs with switches. The switch reduces the risk of an attacker capturing data with a sniffer. Of course, switches also increase the efficiency of a network.

Full Security+ Course

SY0-501 Full Security+ Course

Helping you Pass the First Time

Online access includes all of the content from the

CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide

  • Introduction
  • About the exam (including information on the number of questions, test duration, passing score, types of questions and more. Also includes a listing of the exam objectives)
  • 75 question pre-assessment exam
  • Mastering Security Basics (full content from Chapter 1 of the study guide including the exam topic review and 15 practice test questions)
  • Understanding Identity and Access Management (full content from Chapter 2 of the study guide including the exam topic review and 15 practice test questions)
  • Exploring Network Technologies and Tools (full content from Chapter 3 of the study guide including the exam topic review and 15 practice test questions)
  • Securing Your Network (full content from Chapter 4 of the study guide including the exam topic review and 15 practice test questions)
  • Securing Hosts and Data (full content from Chapter 5 of the study guide including the exam topic review and 15 practice test questions)
  • Comparing Threats, Vulnerabilities, and Common Attacks (full content from Chapter 6 of the study guide including the exam topic review and 15 practice test questions)
  • Protecting Against Advanced Attacks (full content from Chapter 7 of the study guide including the exam topic review and 15 practice test questions)
  • Using Risk Management Tools (full content from Chapter 8 of the study guide including the exam topic review and 15 practice test questions)
  • Implementing Controls to Protect Assets (full content from Chapter 9 of the study guide including the exam topic review and 15 practice test questions)
  • Understanding Cryptography and PKI (full content from Chapter 10 of the study guide including the exam topic review and 15 practice test questions)
  • Implementing Policies to Mitigate Risks (full content from Chapter 11 of the study guide including the exam topic review and 15 practice test questions)
  • 75 question post-assessment exam
  • Glossary

Get the SY0-501 Full Security+ Course Here


Test your readiness with these quality materials

Random 75-question tests

Random practice tests from the all of the practice test questions in the CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide. All questions include explanations so you'll know why the correct answers are correct, and why the incorrect answers are incorrect.

3 sets Performance-based Questions

Three new sets of performance-based questions with a total of 30 questions. These new questions use a new testing engine that includes realistic drag and drop, matching, sorting, and fill in the blank questions.

Flashcard Set

  • 494 Online Security+ Glossary Flashcards
  • 222 Online Security+ Acronyms Flashcards
  • 223 Online Security+ Remember This Slide from the popular CompTIA Security+ Get Certified Get Ahead: SY0-501 Study Guide

Audio - SY0-501 Security+ Remember This Audio Files

Learn by Listening. Over one hour and 20 minutes of audio (MP3 downloads.)

Audio - SY0-501 Security+ Question and Answer Audio Files

Learn by Listening. Over two hours hour and 53 minutes of audio (MP3 downloads.)

Bonus #1

Audio from the end of chapter reviews from each of the chapters in the CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide. Over one hour and 40 minutes of additional audio.

Bonus #2

Access to all of the online content that is available for free to anyone that purchases the CompTIA Security+ Get Certified Get Ahead: SY0-501 Study Guide. This includes labs, extra practice test questions, and supplementary materials

Bonus #3 

Access the study materials for a total of 60 days because sometimes life happens.

Get the SY0-501 Full Security+ Course Here

Physical Security of a Switch

Many switches have a console port that administrators can use to monitor all traffic. Unlike the normal ports that only see traffic specifically addressed to the port, the monitoring port will see all traffic in or out of the switch. This includes any unicast traffic the switch is internally switching between two regular ports. The monitoring port is useful for legitimate troubleshooting, but if the switch isn’t protected with physical security, it can also be useful to an attacker.

Physical security protects a switch by keeping it in a secure area such as in a locked wiring closet. Physical security ensures that attackers don’t have physical access to the switch and other network devices.

Loop Protection

In some situations, a network can develop a switching loop or bridge loop problem. The effect is similar to a broadcast storm and it can effectively disable a switch. For example, if a user connects two ports of a switch together with a cable, it creates a switching loop where the switch continuously sends and resends unicast transmissions through the switch. In addition to disabling the switch, it also degrades performance of the overall network.

This is trivial for many network administrators, because most current switches have Spanning Tree Protocol (STP) or the newer Rapid STP (RSTP) installed and enabled. STP and RSTP protect against switching loops. However, if these protocols are disabled, the switch is susceptible to loop problems. The simple solution is to ensure that switches include loop protection such as STP or RSTP.

Spanning Tree Protocol also protects the network against potential attackers. For example, imagine an attacker visits a conference room and has access to RJ-45 wall jacks. If loop protection isn’t enabled, he can connect two jacks together with a cable, slowing network performance down to a crawl.

Remember this

Loop protection such as STP or RSTP is necessary to protect against switching loop problems, such as those caused when two ports of a switch are connected together.


 

Q. Your organization has several switches used within the network. You need to implement a security control to secure the switch from physical access. What should you do?

A. Disable unused ports.

B. Implement an implicit deny rule.

C. Disable STP.

D. Enable SSH.

Answer is A. You can provide added security by disabling unused physical ports on the switch. If someone gains physical access to the switch by plugging in a computer to one of its unused ports, that person will not be able to connect to the network.

An implicit deny rule is placed at the end of an access control list on a router to deny traffic that hasn’t been explicitly allowed, but it doesn’t not affect physical ports differently.

Spanning Tree Protocol (STP) prevents switching loop problems and should be enabled.

Secure Shell (SSH) encrypts traffic but doesn’t protect a switch.

See Chapter 3 of the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide for more information on basic network security.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

CompTIA Security+ Get Certified Get Ahead: SY0-501 Study Guide

Subscribe To Our Newsletter

Join our mailing list and get a free excerpt of the CompTIA Security+: Get Certified Get Ahead: SY0-501 Study Guide.  This excerpt includes the introduction and Chapter 1. 

You have Successfully Subscribed!

Get Certified Get Ahead is a participant in the Amazon Services LLC Associates Program,
an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.

Copyright © 2015 Get Certified Get Ahead. All Rights Reserved.