Networking Fundamentals for VAPT – Complete Course Content

Course Overview

Course Name: Networking Fundamentals for Cyber Security, VAPT & Ethical Hacking

Level: Beginner to Intermediate

Recommended Duration: 4 Weeks

Training Approach: Theory, Demonstrations, Command-Line Practice and Hands-on Labs

Target Audience: Freshers, IT Professionals, Software Testers, System Administrators, Network Engineers and Aspiring Cyber Security Professionals.

Module 1: Introduction to Computer Networking

• What is Computer Networking?
• Why is Networking Important in Cyber Security?
• Advantages and Disadvantages of Computer Networks
• Types of Networks: LAN, WAN, MAN, PAN and WLAN
• Client-Server Architecture
• Peer-to-Peer Networking
• Intranet, Extranet and Internet
• Network Topologies: Star, Bus, Ring, Mesh and Tree
• Network Communication Fundamentals
• How Computers Communicate Over a Network
• Real-Time Networking Examples
• Role of Networking in VAPT

Practical Lab: Identify network devices and observe how a computer connects to the Internet.

Module 2: OSI and TCP/IP Models

• Introduction to the OSI Model
• Seven Layers of the OSI Model
• Physical Layer
• Data Link Layer
• Network Layer
• Transport Layer
• Session Layer
• Presentation Layer
• Application Layer
• Functions of Each Layer
• Introduction to the TCP/IP Model
• Four Layers of the TCP/IP Model
• OSI Model vs TCP/IP Model
• Encapsulation and Decapsulation
• Data, Segments, Packets, Frames and Bits
• Protocols Associated with Each Layer
• Troubleshooting Using Network Layers

Practical Lab: Map common network protocols to their corresponding layers and inspect packet captures.

Module 3: IP Addressing Fundamentals

• What is an IP Address?
• IPv4 Addressing
• IPv6 Addressing
• IPv4 Address Format
• Binary and Decimal Conversion
• Public IP vs Private IP
• Static IP vs Dynamic IP
• Valid and Invalid IPv4 Addresses
• Loopback Address
• Link-Local Addresses
• Network Address and Broadcast Address
• Host Addressing
• Unicast, Broadcast and Multicast
• IPv4 vs IPv6
• IP Address Configuration
• IP Address Identification in Windows and Linux
• IP Addressing in VAPT

Practical Lab: Identify IP addresses, network interfaces and local network configurations.

Module 4: Subnetting and CIDR

• What is Subnetting?
• Why is Subnetting Required?
• What is a Subnet Mask?
• Network Portion vs Host Portion
• CIDR Notation
• Understanding /8, /16, /24, /25, /26, /27, /28 and /30
• Network Address Calculation
• Broadcast Address Calculation
• Usable Host Address Range
• Number of Hosts in a Subnet
• Basic Subnetting Calculations
• Introduction to IPv6 Prefixes
• Understanding Network Ranges
• Subnetting in Internal Network Assessments
• CIDR Scope Interpretation in VAPT

Practical Lab: Calculate subnet ranges and determine the addresses included in a given authorized network scope.

Module 5: MAC Addresses and ARP

• What is a MAC Address?
• MAC Address Format
• MAC Address vs IP Address
• Physical Address Identification
• Unicast and Multicast MAC Addresses
• Introduction to ARP
• How ARP Works
• ARP Request and ARP Reply
• ARP Cache
• Viewing ARP Entries
• ARP vs IPv6 Neighbor Discovery
• Understanding Local Network Communication
• ARP-Related Security Risks
• Introduction to ARP Spoofing and Defensive Measures

Practical Lab: View local ARP entries and examine ARP packets in an authorized lab.

Module 6: TCP, UDP and Port Numbers

• Introduction to the Transport Layer
• What is TCP?
• What is UDP?
• TCP vs UDP
• TCP Header Fundamentals
• UDP Header Fundamentals
• Source Port and Destination Port
• Well-Known Ports
• Registered Ports and Dynamic Ports
• TCP Three-Way Handshake
• SYN, SYN-ACK and ACK
• TCP Connection Termination
• TCP Flags: SYN, ACK, FIN, RST and PSH
• Connection-Oriented and Connectionless Communication
• Listening Ports and Established Connections
• Open, Closed and Filtered Port States
• Port Numbers in VAPT
• Understanding Service Exposure

Practical Lab: View listening ports and inspect TCP handshakes using approved diagnostic tools.

Module 7: Common Network Protocols and Ports

Learn the purpose, default ports and security considerations of common protocols.

• FTP — Ports 20 and 21
• SSH — Port 22
• Telnet — Port 23
• SMTP — Port 25
• DNS — Port 53
• DHCP — UDP Ports 67 and 68
• HTTP — Port 80
• POP3 — Port 110
• NTP — Port 123
• IMAP — Port 143
• SNMP — Port 161
• LDAP — Port 389
• HTTPS — Port 443
• SMB — Port 445
• MySQL — Port 3306
• RDP — Port 3389
• PostgreSQL — Port 5432
• VNC — Commonly Port 5900
• Alternate HTTP Services — Commonly Port 8080

Additional topics:

• TCP Ports vs UDP Ports
• Common vs Actual Service Ports
• Port-to-Service Mapping
• Service Identification
• Risks Associated with Exposed Services
• Service Hardening Fundamentals

Practical Lab: Identify ports and services on local lab systems and document the findings.

Module 8: DNS – Domain Name System

• What is DNS?
• Why is DNS Required?
• Domain Names and IP Addresses
• DNS Resolution Process
• Recursive and Authoritative DNS Servers
• DNS Root Servers
• Top-Level Domains
• DNS Caching
• DNS Resolver
• DNS Record Types
• A Record
• AAAA Record
• CNAME Record
• MX Record
• NS Record
• TXT Record
• PTR Record
• SOA Record
• Forward and Reverse DNS Lookup
• DNS Troubleshooting
• DNS Security Fundamentals
• DNS Spoofing Concepts
• DNS Misconfiguration Risks
• DNS Information Gathering Within Authorized Scope

Practical Lab: Use nslookup and dig to query DNS records and understand the returned results.

Module 9: DHCP, ICMP and Network Diagnostics

DHCP

• What is DHCP?
• Dynamic IP Address Assignment
• DHCP DORA Process
• DHCP Discover
• DHCP Offer
• DHCP Request
• DHCP Acknowledgment
• DHCP Lease
• DHCP Server and Client

ICMP

• What is ICMP?
• ICMP Echo Request and Echo Reply
• Ping Utility
• ICMP Error Messages
• Traceroute and Tracert
• TTL Fundamentals
• Connectivity Troubleshooting
• Why Ping May Fail Even When a Host Is Online

Practical Lab: Troubleshoot connectivity and interpret ping and traceroute results.

Module 10: Routing and Network Communication

• What is Routing?
• Router Functions
• Routing Table
• Default Gateway
• Default Route
• Directly Connected Routes
• Static Routing
• Dynamic Routing Overview
• Inter-Network Communication
• Same-Subnet vs Different-Subnet Communication
• Packet Forwarding
• Routing Metrics at a Basic Level
• Understanding Network Reachability
• Routing Problems and Troubleshooting
• Network Paths in VAPT

Practical Lab: View the routing table and identify the default gateway using Windows and Linux commands.

Module 11: Network Devices and Security Architecture

• Network Interface Card (NIC)
• Hub and Switch
• Router
• Firewall
• Modem
• Wireless Access Point
• Proxy Server
• Reverse Proxy
• Load Balancer
• Network Address Translation (NAT)
• Port Address Translation (PAT)
• Virtual Private Network (VPN)
• Virtual LAN (VLAN)
• Network Segmentation
• Demilitarized Zone (DMZ)
• Network Access Control
• Stateful and Stateless Firewalls
• Allow and Deny Rules
• Inbound and Outbound Traffic
• Network Security Zones
• Principle of Least Privilege
• Common Network Misconfigurations

Practical Lab: Draw a basic enterprise network diagram and identify the locations of firewalls, gateways, servers and security boundaries.

Module 12: HTTP, HTTPS and Web Networking

• Introduction to HTTP
• How Web Browsers Communicate With Web Servers
• HTTP Request and Response
• HTTP Methods: GET, POST, PUT, PATCH, DELETE and HEAD
• HTTP Request Headers
• HTTP Response Headers
• URL Structure
• Query Parameters
• Cookies
• Sessions
• HTTP Status Codes
• Redirection
• HTTP vs HTTPS
• TLS Fundamentals
• Digital Certificates
• Certificate Authority
• Certificate Expiry and Hostname Validation
• TLS Handshake Overview
• Encryption in Web Communication
• Common Web Configuration Weaknesses
• Basic Web Troubleshooting
• Networking Concepts Used in Web Application VAPT

Practical Lab: Use browser Developer Tools and curl to inspect HTTP response headers and status codes.

Module 13: Email and Directory Services

• SMTP Fundamentals
• POP3 Fundamentals
• IMAP Fundamentals
• Email Communication Flow
• Mail Servers and Mail Clients
• MX Records
• SPF, DKIM and DMARC Overview
• LDAP Fundamentals
• Active Directory Networking Overview
• Directory Services and Authentication
• Windows File Sharing Fundamentals
• SMB Overview
• Remote Administration Services
• Common Service Exposure Risks
• Secure Configuration Fundamentals

Practical Lab: Examine publicly available DNS mail records for an authorized domain and study protocol behavior in a controlled environment.

Module 14: Windows and Linux Networking Commands

Windows Commands

• ipconfig
• ipconfig /all
• ping
• tracert
• nslookup
• arp -a
• route print
• netstat -ano
• hostname
• curl

Linux Commands

• ip addr
• ip route
• ip neigh
• ping
• traceroute
• dig
• ss -tulnp
• ip link
• hostname
• curl

Additional topics:

• Understanding Command Output
• Identifying Local Interfaces
• Viewing Listening Services
• Finding Active Connections
• Checking DNS Resolution
• Identifying the Default Gateway
• Basic Network Troubleshooting
• Command-Line Fundamentals for VAPT

Practical Lab: Complete a networking information-gathering worksheet using Windows or Linux.

Module 15: Network Packet Analysis Using Wireshark

• Introduction to Wireshark
• Packet Capture Fundamentals
• Network Interface Selection
• Capturing Live Traffic in an Authorized Lab
• Packet Details and Packet Bytes
• Ethernet Frames
• IP Packets
• TCP Segments
• UDP Datagrams
• TCP Three-Way Handshake Analysis
• DNS Packet Analysis
• HTTP Request and Response Analysis
• TLS Handshake Overview
• Source and Destination Addresses
• Source and Destination Ports
• Wireshark Display Filters
• Identifying Communication Errors
• Exporting and Saving Packet Captures
• Packet Analysis for Security Investigations
• Limitations of Encrypted Traffic Analysis

Practical Lab: Capture and analyze DNS queries, TCP handshakes and authorized HTTP traffic.

Module 16: Network Discovery and Port Scanning Using Nmap

• Introduction to Nmap
• Why Network Discovery Is Used
• Host Discovery Concepts
• TCP and UDP Scanning Fundamentals
• Understanding Port States
• Service and Version Detection
• Scan Timing and Accuracy
• Target Specification
• CIDR Target Notation
• Reading Nmap Results
• Identifying Exposed Services
• Understanding Firewall Effects on Results
• Service Enumeration Fundamentals
• Documenting Scan Results
• Limitations of Port Scanning
• Authorized Network Assessment Practices

Practical Lab:

• Scan a deliberately configured local lab machine.
• Identify open and closed ports.
• Review detected services.
• Compare results with the lab machine’s configuration.
• Prepare a basic service discovery report.

All scans must remain within systems and IP ranges that you own or are explicitly authorized to assess.

Module 17: Networking Security Concepts for VAPT

• Network Attack Surface
• Network Enumeration Fundamentals
• Service Exposure and Misconfiguration
• Weak Network Access Controls
• Insecure Remote Administration
• Unnecessary Open Ports
• Network Segmentation Weaknesses
• Public vs Internal Service Exposure
• Firewall Rule Review
• DNS Misconfiguration
• Basic Network Spoofing Concepts
• Man-in-the-Middle Attack Concepts
• Network Sniffing Concepts
• Denial-of-Service Concepts and Defensive Awareness
• Secure Network Configuration
• Logging and Monitoring
• Remediation Recommendations
• Rules of Engagement
• Scope and Authorization
• Responsible Reporting

This module emphasizes identifying, understanding and reporting security weaknesses rather than testing unauthorized systems.

Module 18: Network Assessment Workflow for VAPT

• Understanding the Assessment Scope
• Confirming Written Authorization
• Reviewing Target IP Ranges
• Identifying Network Boundaries
• Understanding the Target Environment
• Performing Approved Host Discovery
• Conducting Approved Port Scans
• Identifying Network Services
• Reviewing Service Configurations
• Validating Findings Safely
• Assessing Risk and Business Impact
• Recording Evidence
• Preparing a Vulnerability Report
• Recommending Remediation
• Retesting After Fixes
• Maintaining Professional Documentation

Practical Lab: Perform a small, authorized network assessment against a dedicated lab environment and prepare a report containing scope, methodology, findings and recommendations.

Final Assessment and Hands-on Project

Project: Basic Network Security Assessment

Students will work with a deliberately configured lab network.

Project Tasks:

1. Document the approved scope and lab topology.
2. Identify the host’s IP configuration.
3. Calculate the relevant network range.
4. Review connectivity and routing.
5. Identify listening ports and services.
6. Perform an authorized Nmap scan.
7. Analyze selected packets using Wireshark.
8. Explain the security implications of exposed services.
9. Document findings and limitations.
10. Recommend suitable hardening measures.

Expected Deliverables:

• Network diagram.
• IP Addressing and Subnetting Worksheet.
• Port and Service Inventory.
• Packet Analysis Notes.
• Network Assessment Report.
• Remediation Recommendations.

Learning Outcomes

After completing this course, students should be able to:

• Understand core networking concepts.
• Explain the OSI and TCP/IP Models.
• Work with IPv4, IPv6 and subnetting.
• Understand TCP, UDP and port numbers.
• Identify common networking protocols and services.
• Troubleshoot basic DNS, routing and connectivity issues.
• Use standard Windows and Linux networking commands.
• Analyze basic network packets with Wireshark.
• Interpret network discovery and Nmap scan results.
• Understand network security risks and configuration weaknesses.
• Prepare a basic network assessment report.
• Progress toward VAPT and Ethical Hacking training.

Recommended Prerequisites

No advanced networking experience is required. Basic computer usage and a willingness to learn command-line tools are sufficient to start.

Students should build their practical skills progressively and use authorized lab systems throughout the course.

Recommended Next Course

After completing Networking Fundamentals, students can proceed to:

1. Linux Fundamentals for Cyber Security.
2. Web Technologies and HTTP Fundamentals.
3. Security Testing Tools and Methodologies.
4. Web Application VAPT.
5. API Security Testing.
6. Network Penetration Testing.
7. Android Application Security Testing.
8. Vulnerability Reporting and Remediation.

For your goal of learning Networking Fundamentals for VAPT and Ethical Hacking, I recommend a learning path that starts with basic networking, then covers IP addressing and subnetting, followed by packet analysis and Nmap.

You do not need to purchase every course below. Start with one comprehensive networking course and add the specialized courses as you progress.

1. Best Udemy courses for your learning path

Start here

1. Introduction to Computer Networking – Beginner Crash Course

Instructor: Rick Crisci

⭐ 4.7/5 · Around 16,000 ratings · Updated February 2026

Covers TCP/IP, OSI Model, IP addressing, subnetting, Ethernet, DNS, DHCP, routing, switches, VPNs and VLANs. Suitable for learners starting without networking experience.

Beginner Crash Course

+1

View course on Udemy

2. The Complete IP Subnetting Course: Beginner to Advanced!

Instructor: Learn to Excel Online

⭐ 4.7/5 · Around 5,300 ratings · Listed as free when checked

Focuses on subnet masks, binary conversions, CIDR, IPv4 network ranges and subnet calculations. Particularly helpful before learning network scanning. The listed course was last updated in September 2019.

Udemy

View course on Udemy

3. Getting Started with Wireshark: The Ultimate Hands-On Course

Instructors: David Bombal and Chris Greer

⭐ 4.8/5 · Around 12,000 ratings · Approximately 4.5 hours

Covers packet capture, DNS, DHCP, TCP/IP, troubleshooting and network traffic analysis. This is a strong follow-up after learning networking fundamentals.

Udemy

View course on Udemy

4. Nmap for Ethical Hackers – The Ultimate Hands-On Course

Instructors: David Bombal and Chris Greer

⭐ 4.7/5 · Around 1,800 ratings · Approximately 3.5 hours

Covers network discovery, open ports, service/version detection, enumeration and interpreting scan results. Its listed update is April 2023, so check the preview and curriculum before enrolling.

The Ultimate Hands-On Course

View course on Udemy

2. Optional alternatives

If you prefer a more extensive networking course or need additional practice, consider these:

5. Microsoft Networking Fundamentals

⭐ 4.7/5 · Approximately 14 hours

A broader course covering OSI, TCP/IP, IPv4/IPv6, subnetting, routing, switching, Windows networking and command-line tools. A good alternative to the first course if you want more depth.

Udemy

View course on Udemy

6. CompTIA Network+ N10-009 Full Course, Labs, Course Notes

⭐ 4.8/5 · Labs and course notes

A more comprehensive option if you want structured networking study, practical labs and certification preparation alongside your VAPT learning.

Udemy

View course on Udemy

3. My recommended learning order

Step	What to study	Approximate time
1	Computer Networking Fundamentals	1–2 weeks
2	IP Addressing and Subnetting	3–5 days
3	Wireshark Packet Analysis	3–4 days
4	Nmap for Ethical Hackers	2–3 days
5	Practice and revision	3–5 days

The durations are study-time estimates, not the actual video lengths. Allow extra time for exercises and revision.

My recommendation: Start with Introduction to Computer Networking – Beginner Crash Course, use the free subnetting course to strengthen IP calculations, and then move to Wireshark and Nmap. You can skip the optional alternatives unless you need more depth.

Most of these courses are taught in English. Check the preview lessons and available captions before purchasing. Udemy prices, discounts and course details can change, so verify the current listing before enrolling.

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The Udemy courses are sufficient to build your basic Networking foundation for VAPT, but they are not sufficient by themselves to cover every topic in your complete 18-module syllabus.

The good news is that you do not need to buy more courses immediately. Complete these four courses, practice the concepts, and fill the specific gaps listed below.

1. How much of your syllabus will they cover?

Your course content	Coverage
Networking fundamentals and OSI Model	✅ Strong
TCP/IP Model and encapsulation	✅ Strong
IPv4, private/public IPs and subnetting	✅ Strong
MAC addresses, Ethernet and ARP	✅ Mostly covered
TCP, UDP and ports	✅ Core concepts covered
DNS and DHCP	✅ Covered
Routing and network devices	✅ Fundamentals covered
Common protocols and port numbers	⚠️ Some additional study needed
HTTP, HTTPS and TLS	⚠️ Study in more depth
Firewalls, NAT, VPNs and VLANs	✅ Fundamentals; security details need practice
Windows and Linux networking commands	⚠️ Practice separately
Wireshark packet analysis	✅ Dedicated course
Nmap and service discovery	✅ Dedicated course
LDAP, SMB, RDP and email protocols	⚠️ Study individually
Network security architecture and segmentation	⚠️ Additional study needed
VAPT assessment, reporting and remediation	❌ Not fully covered by these networking courses

The networking course by Rick Crisci covers fundamentals such as IP addressing, subnetting, switches, routers, DNS, DHCP, NAT, VPNs and VLANs. The subnetting course gives additional IPv4 practice, while the Wireshark and Nmap courses focus on practical packet analysis and service discovery.

Beginner Crash Course

+3

2. Follow this learning order

1. Networking fundamentals

Rick Crisci — Networking Basics

Learn first: OSI, TCP/IP, network devices, IP addressing and core protocols.

2. Subnetting practice

Complete IP Subnetting Course

Learn if you need more practice with CIDR, subnet masks, network ranges and host calculations. Skip it initially if the first course’s bonus subnetting lessons are enough.

3. Packet analysis

Wireshark Hands-On Course

Practice DNS queries, TCP handshakes, protocol analysis and troubleshooting.

4. Network discovery

Nmap for Ethical Hackers

Practice authorized host discovery, port scanning and service identification in a lab.

3. What should you study separately?

After completing those courses, focus on these five areas:

1. Protocols: SMTP, FTP, SSH, SMB, LDAP, RDP, SNMP and their common security risks.
2. Web networking: HTTP methods, headers, status codes, cookies, TLS certificates and TLS handshakes.
3. Network troubleshooting: ipconfig, ip route, netstat, ss, tracert, traceroute, ping and nslookup.
4. Network security: Firewall rules, VPNs, DMZs, VLAN segmentation and network access controls.
5. VAPT workflow: Scope definition, authorized scanning, service identification, finding validation, reporting, remediation and retesting.

You can learn these through vendor documentation, short tutorials and hands-on exercises rather than purchasing another complete course.

My final recommendation

Complete the four Udemy courses in the sequence above, then use your 18-module syllabus as a checklist. Spend extra time on practical exercises rather than watching additional videos without practice.

Your target should be: Understand the networking concepts, interpret actual command and packet-capture results, identify exposed services on your own lab systems, and explain the security implications of your findings.

Once you achieve that, you will have a solid networking foundation to begin Web Application VAPT, API Security Testing and Network Penetration Testing.