If you’re planning on taking the Security+ exam, you should have a basic understanding of protocols used with VPNs. For example, can you answer this question?
Q. Your organization is planning to implement a VPN and wants to ensure it is secure. Which of the following protocols is the BEST choice to use with the VPN?
A. HTTP
B. SFTP
C. IPsec
D. PPTP
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+ (SY0-601) Practice Test Questions
SY0-601 Practice Test Questions
Over 385 realistic Security+ practice test questions
At least 10 performance-based questions
All questions include explanations so you’ll know why the correct answers are correct,
and why the incorrect answers are incorrect.
Upgrade Your Resume with the Security+ New Version
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.
- 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 – 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.
Pass the First Time You Take It
Get the full bank of SY0-601 Practice Test Questions Here
Click here if you’re looking for SY0-501 Online Study Package
Connecting via Remote Access
The following figure shows three examples of how users can connect to internal networks from remote locations. The first VPN client connects to the Internet using a broadband connection to an Internet Service Provider (ISP), and the second VPN client connects to the Internet using a dial-up connection to an ISP. The third client bypasses the Internet and instead uses a dial-up connection directly to the RAS server.

Connecting to a VPN server and a RAS server
The figure shows the VPN server and RAS server between two firewalls (configured as a DMZ). The firewalls provide some protection for the servers and the private network. The VPN server is reachable through a public IP address, making it accessible from any other host on the Internet and the RAS server is reachable through a phone line. Both the VPN server and RAS server use an internal RADIUS server to authenticate clients before granting them access to the internal network.
Of course, the firewall access control lists (ACLs) need to include rules allowing the traffic. The ports you open are dependent on the tunneling protocols used for the VPN.
CompTIA Security+ Study Guide
The
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide
is an update to the top-selling SY0-201, SY0-301, SY0-401, and SY0-501 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 four 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 SY0-601 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.
IPsec as a Protocol Used with VPNs
IPsec supports Tunnel mode, which encrypts the entire IP packets, and is the mode used with VPNs. Transport mode only encrypts the payload within the IP packets and is used within private networks.
IPsec provides security in two ways:
- Authentication. IPsec includes an Authentication Header (AH) to allow each of the hosts in the IPsec conversation to authenticate with each other before exchanging data. AH provides authentication and integrity. AH uses protocol ID number 51.
- Encryption. IPsec includes Encapsulating Security Payload (ESP) to encrypt the data and provide confidentiality. ESP includes AH so it provides authentication, integrity, and confidentiality. ESP uses protocol ID number 50.
The term protocol ID number may look like a typo, but it isn’t. AH and ESP are identified with protocol ID numbers, not port numbers. A basic packet-filtering firewall can filter packets based on IP addresses, ports, and some protocols, such as Internet Control Message Protocol (ICMP) and IPsec. Packet filters use the protocol ID numbers to identify AH and ESP traffic.
IPsec uses Internet Key Exchange (IKE) over port 500 to authenticate clients in the IPsec conversation. IKE creates security associations (SAs) for the VPN and uses these to set up a secure channel between the client and the VPN server.
Remember this
IPsec is a secure encryption protocol used with VPNs. Encapsulating Security Payload (ESP) provides confidentiality, integrity, and authentication for VPN traffic. IPsec uses Tunnel mode for VPN traffic and can be identified with protocol ID 50 for ESP. It uses IKE over port 500.
L2TP and IPsec
Cisco and Microsoft joined forces to create the Layer 2 Tunneling Protocol (L2TP). Although it is possible to use L2TP to create a tunnel between devices, L2TP doesn’t include any encryption, so it does not provide confidentiality of the data. However, you can combine IPsec with L2TP (as L2TP/IPsec) to provide security for the VPN tunnel. L2TP uses UDP port 1701.
NAT and IPsec
IPsec and Network Address Translation (NAT) are not compatible with each other. NAT manipulates the IP header of the packets when it translates the IP addresses. This change causes the receiving end of the VPN tunnel to discard the packet as invalid.
If the path to the VPN server is through a device using NAT, you need to look for alternatives. NAT Traversal (NAT-T) is one possible choice, or you could use another tunneling protocol.
Full Security+ Course
SY0-601 Full Security+ Course
Helping you Pass the First Time
This course includes all of the multiple-choice practice test questions, performance-based questions, audio, and flashcards from the but adds the CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide within an online course.
Test your readiness with these quality materials
Here’s what you get
Random 75-question tests
Random practice tests from the all of the practice test questions in the
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide. All questions include explanations so you’ll know why the correct answers are correct, and why the incorrect answers are incorrect.
Performance-based 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.
Online Flashcard Set
Audio – SY0-601 Security+ Remember This Audio Files
Learn by Listening (MP3 downloads.)
Audio – SY0-601 Security+ Question and Answer Audio Files
Learn by Listening (MP3 downloads.)Bonus #1
The same set of questions organized by domain including questions in the
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide plus extra practice test questions.
Bonus #2
Audio from the end of chapter reviews from each of the chapters in the
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide.
Bonus #3
Access to all of the online content that is available for free to anyone that purchases the CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide. This includes labs, extra practice test questions, and supplementary materials.Bonus #4
Extended access. Access the study materials for a total of 60 days because sometimes life happens.Bonus #5
10% off Voucher Code. Access to a coupon code that will give you 10% off your exam voucher. At the current price of $370 USD for the Security+ voucher, this can save you $37.Get the SY0-601 Full Security+ Course Here
Q. Your organization is planning to implement a VPN and wants to ensure it is secure. Which of the following protocols is the BEST choice to use with the VPN?
A. HTTP
B. SFTP
C. IPsec
D. PPTP
Answer is C. Internet Protocol secure (IPsec) is one of several protocols used to secure virtual private network (VPN) traffic. It is the best choice of the available answers.
Hypertext Transfer Protocol (HTTP) doesn’t provide any security.
Secure File Transfer Protocol (SFTP) secures FTP transmissions but not VPNs.
Point-to-Point Tunneling Protocol (PPTP) is an older protocol used with VPNs, but it is not as secure as IPsec.
See Chapter 4 of the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide for more information on remote access.