Certified Network Security Specialist Review

Certified Network Security Specialist (CNSS) is one of the courses and certifications provided by International CyberSecurity Institute (ICSI) which is an institute based in United Kingdom (UK) and has earned accreditation from Council for Registered Ethical Security Testers (CREST) and National Cyber Security Centre (NCSC). This course provides a holistic view of modern network security including operating system hardening, firewalls, intrusion-detection systems, VPNs and Encryption. Physical Security, Standards, System Security and Security Policies are also included.


While scrolling on Google Chrome’s suggested news on my phone, I found an article about a free network security course make available for people to improve their skills while dealing with COVID-19. My first thought was that I have never heard about this institute before, so I was not sure about the quality of the course or recognition that its certification will provide. I then found that this institute has also been accredited by CREST which is well-recognized accreditation within PenTester cycle. Since this course is free and institute has been accredited by CREST, I decided to give it a try to see quality of its contents.


As I have had learned and certified on some of the information security and network security courses such as Offensive Security Certified Professional (OSCP), Cisco Certified Network Associate Cyber Ops (CCNA Cyber Ops), Cisco Certified Networking Associate Security (CCNA Security), Certified Secure Computer User (CSCUv2) and Juniper Networks Certified Specialist Security (JNCIS-SEC) prior to attending this course, I found that I was familiar with around 90% of contents within the course. For more information related to what are covered within this course, please refer to the Course Outline section below. I spent just a day to go through and finish the course. After completed the course, I have 2 choices, just take the course completion certificate or take the certification exam to get certified.

Certification Exam

One important thing to note about this deal is that exam and labs are not included as part of this offer. You can however, complete the course and also receive your digital certificate of attendance. If you to want get CNSS certified, you will need to purchase the certification exam voucher and labs (valid for 6 months), you have to pay £75.00 which is around $100.

Below are the exam details.

Certification Name: ICSI | CNSS Certified Network Security Specialist
Exam Code: CNSS
Exam Type: 100 Multiple Choice Questions (Closed Book)
Time Allowed: 2 Hours and 30 minutes
Pass Mark: 70%
Validity: Does not expire
Exam Fee: £75.00 (valid for 6 months with online labs included)

For me, I decided not to take certification exam due to the fact I have had several certifications in this field already, so I don’t think that it is necessary for me to take this certification.

Final Thought

I think this course is good for students or newbie network engineer who would like to expand their knowledge on network security. I would say that most of this course are focusing on the delivering theory rather than practical skills. If you have not had any network security certifications yet and would like to get one, I think this is one of the best deal for you. You can claim this course for free, then purchase exam voucher around $100 and sit in the exam to get certified. With this COVID-19 deal, I don’t think you can find any other network security courses or certifications out there with the price as low as this one.

However, if we look at the full course and exam fee for CNSS without COVID-19 deal, we can see that it is £500 which is around $650. If we take into account the full course and exam fee and compare it with similar course within this price range such as Certified Network Defender (CND) by EC-Council or Practical Network Defense (PND) by eLearnSecurity, we can see that CND and PND has more modules and covered more domains of knowledge than CNSS. If you want to learn more on theory of network security, I think CND would give you more bang for the buck than CNSS. If you want to learn more hand-on skills of network security, I would suggest you to go with PND. In term of certification validity, CNSS and PND will not expire after you own it. On the other hand, CND will be valid for 3 years after you own it, and you will need to renew it in order to keep it valid.

Course Outline

This course has 13 modules, and each module ends with a quiz.

  1. Module 1: Introduction to Network Security
    • Network Basics
    • Guided Exercise: Analysing Network Traffic
    • Guided Exercise: Analysing Telnet Network Traffic
    • Basic Network Utilities
    • Guided Exercise: Using Basic Network Utilities
    • The OSI Model
    • Threat Classification
    • Security Terminology
    • Approaches of Network Security
    • Law and Network Security
    • Quiz
  2. Module 2: Types of Attacks
    • Denial of Service Attacks
    • Buffer Overflow Attacks
    • IP Spoofing
    • Guided Exercise: Preventing IP Spoofing
    • Session Hijacking
    • Quiz
  3. Module 3Fundamentals of Firewalls
    • What is a Firewall
    • Firewall Types
    • Firewall Implementation
    • Proxy Servers
    • Windows Firewalls
    • Guided Exercise: Configuring Windows Firewall
    • Linux Firewalls
    • Guided Exercise: Configuring iptables Rules
    • Quiz
  4. Module 4: Intrusion-Detection Systems
    • IDS Concepts
    • Components and Processes of IDSFREE PREVIEW
    • Implementing IDSFREE PREVIEW
    • Guided Exercise: Implementing an IDSFREE PREVIEW
    • Honeypots
    • Quiz
  5. Module 5: Fundamentals of Encryption
    • The History of Encryption
    • Modern Encryption Methods
    • Windows and Linux Encryption
    • Guided Exercise: Enabling BitLocker
    • Guided Exercise: Encrypting a Folder Using EFS
    • Hashing
    • Guided Exercise: Hashing
    • Cracking Passwords
    • Rainbow Tables
    • Guided Exercise: Cracking Passwords
    • Quiz
  6. Module 6: Virtual Private Networks (VPN)
    • Introduction to VPN
    • VPN Protocols
    • IPSec
    • SSL/TLS
    • VPN Solutions
    • Quiz
  7. Module 7: Operating System Hardening
    • Configuring Windows
    • Guided Exercise: Password Policies
    • Configuring Linux
    • Guided Exercise: Linux File Permissions
    • Guided Exercise: Disabling Linux Services
    • Operating System Patches
    • Quiz
  8. Module 8: Virus Attacks and How to Defend
    • Virus Types and Attacks
    • Virus Scanners
    • Antivirus
    • Guided Exercise: Scanning for Viruses
    • Virus Infection and Identification
    • Trojan Horses
    • Spyware or Adware
    • Quiz
  9. Module 9: Security Policies
    • User Policies Definition
    • Guided Exercise: Analysing Policies
    • System Administration Policies
    • Access Control
    • Quiz
  10. Module 10: Assessing System Security
    • Risk Assessment
    • Conducting an Initial Assessment
    • Probing the Network
    • Guided Exercise: Probing the Network
    • Vulnerabilities
    • Guided Exercise: Learning about Vulnerabilities
    • Documenting Security
    • Quiz
  11. Module 11: Security Standards
    • ISO Standards
    • NIST Standards
    • General Data Protection Regulation (GDPR)
    • PCI DSS
    • Quiz
  12. Module 12: Physical Security and Recovery
    • Physical Security
    • Disaster Recovery
    • Fault Tolerance
    • Guided Exercise: Backup Windows 10
    • Quiz
  13. Module 13: Attackers Techniques
    • Hacking Preparation
    • Guided Exercise: Passive Information Gathering
    • The Attack Phase
    • Hacking Wi-Fi
    • Quiz

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3 Responses

  1. Ivan says:

    did you take the exam ?? Because you have prior expertise on the field , I assume it was peace of cake . But for newbies what´s your recommendation

    • KHroot says:

      Hi, Ivan
      I did not take the exam because I thought it will overlap with what I have already had. For newbie recommendation, I think you can refer to Final Thought section.

  1. 14/11/2020

    […] Network Security Specialist (CNSS) course with ICSI before, and you can also find my CNSS review here. I think their contents in CNSS are quite good, so I would like to see the quality of contents […]

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