Network Defense and Countermeasures

I.     Course Prefix/Number: CNS 172

       Course Name: Network Defense and Countermeasures

       Credits: 3 (3 lecture; 1 lab)

II.    Prerequisite

Recommend: CNS 111 or consent of instructor, coordinator or program chair.

III.   Course (Catalog) Description

This course provides students with the knowledge and concepts needed for protecting computers and networks.  The course covers intrusion detection, develop a security policy, implement Network Address Translation (NAT) and packet filtering by installing proxy servers, firewalls, and virtual private network (VPNs).  The course also assists students in preparation for the appropriate Network or Information Security Certification examinations. Recommend: CNS 111 or consent of instructor, coordinator or program chair.

IV.   Learning Objectives

Upon completion of this course the student will be able to understand:

  1. Identify and describe the individuals who might attempt to break into your network
  2. Specify and setup goals for developing a network security system
  3. Determine and list the options for configuring and Integrate an Intrusion Detection System (IDS) into a network security configuration
  4. Identify and explain basics concepts of risk analysis
  5. Understand and design an effective security policy
  6. List the requirements for steps involved in setting up a Bastion Host
  7. Apply and test common firewall configurations
  8. Configure and test Network Address Translation (NAT)
  9. Configure and check Proxy Server to supplement a Firewall with a Proxy Server
  10. Install and configure Microsoft ISA Server 2000
  11. Identify and test the tunneling protocols and schemes that enable secure VPN Connections and encryption Schemes used by VPNs
  12. List and explain the benefits of the common vulnerabilities and exposures (CVE) standard
  13. Demonstrate the necessary response for false alarms to reduce reoccurrences
  14. Explain and analyze options for dealing with legitimate security alerts

V.    Academic Integrity and Student Conduct

Students and employees at Oakton Community College are required to demonstrate academic integrity and follow Oakton's Code of Academic Conduct. This code prohibits:

• cheating,
• plagiarism (turning in work not written by you, or lacking proper citation),
• falsification and fabrication (lying or distorting the truth),
• helping others to cheat,
• unauthorized changes on official documents,
• pretending to be someone else or having someone else pretend to be you,
• making or accepting bribes, special favors, or threats, and
• any other behavior that violates academic integrity.

There are serious consequences to violations of the academic integrity policy. Oakton's policies and procedures provide students a fair hearing if a complaint is made against you. If you are found to have violated the policy, the minimum penalty is failure on the assignment and, a disciplinary record will be established and kept on file in the office of the Vice President for Student Affairs for a period of 3 years.

Please review the Code of Academic Conduct and the Code of Student Conduct, both located online at

VI.   Sequence of Topics

  1. Foundations of Network Security
  2. Designing a Network Defense
  3. Risk Analysis and Security Policy Design
  4. Choosing and Designing Firewalls
  5. Configuring Firewalls
  6. Strengthening and Managing Firewalls
  7. Setting up a Virtual Private Network
  8. Intrusion Detection: An Overview
  9. Intrusion Detection: Preventive Measures
  10. Intrusion Detection: Incident Response
  11. Strengthening Defense through Ongoing Management

VII.  Methods of Instruction

Methods include lectures, class exercises and class discussion, perform lab exercise and projects.
Course may be taught as face-to-face, hybrid or online course.

VIII. Course Practices Required

Read course materials - textbook and current journals
Attend and participate in class lecture and lab
Complete required assignments, exercises, quizzes, and exams

IX.   Instructional Materials

Note: Current textbook information for each course and section is available on Oakton's Schedule of Classes.

Current Network Defense and Countermeasures Text and Lab book:
Current Self-Test Software
Software manuals

X.    Methods of Evaluating Student Progress

Evaluation methods include quizzes, examinations, completion of lab assignments and special exercises.

Final grades are determined through a weighted average of examinations, quizzes, laboratory assignments, homework assignments, class participation, and attendance. After your numerical grade has been calculated, your letter grade will be determined as follows:

A 90–100% of the total percentage points possible
B 80–89% of the total percentage points possible
C 70–79% of the total percentage points possible
D 60–69% of the total percentage points possible
F Less than 60% of the total percentage points possible

XI.   Other Course Information

    In response to Columbine and the NIU tragedies police agencies in Illinois have developed training for law enforcement and the public school systems. These Nationally accepted law enforcement response plans have been adopted by Oakton's Public Safety Department. Your actions will influence others therefore, Oakton is asking you as a student to:
    1. stay calm
    2. secure the immediate area; lock, block & barricade
    3. call 911 and:
      • report your specific location
      • number of people at your location
      • injuries
      • assailants; location, number, race, gender, clothing, physical features, type of weapon

Side Note: There is a phone for emergency purposes placed in each classroom.

If you have a documented learning, psychological, or physical disability you may be entitled to reasonable academic accommodations or services. To request accommodations or services, contact the Access and Disability Resource Center at the Des Plaines or Skokie campus. All students are expected to fulfill essential course requirements. The College will not waive any essential skill or requirement of a course or degree program.

Oakton Community College is committed to maintaining a campus environment emphasizing the dignity and worth of all members of the community, and complies with all federal and state Title IX requirements.

Resources and support for
  • pregnancy-related and parenting accommodations; and
  • victims of sexual misconduct
can be found at

Resources and support for LGBTQ+ students can be found at

Electronic video and/or audio recording is not permitted during class unless the student obtains written permission from the instructor. In cases where recordings are allowed, such content is restricted to personal use only. Any distribution of such recordings is strictly prohibited. Personal use is defined as use by an individual student for the purpose of studying or completing course assignments.

For students who have been approved for audio and/or video recording of lectures and other classroom activities as a reasonable accommodation by Oakton’s Access Disabilities Resource Center (ADRC), applicable federal law requires instructors to permit those recordings. Such recordings are also limited to personal use. Any distribution of such recordings is strictly prohibited.

Violation of this policy will result in disciplinary action through the Code of Student Conduct.