Network Security A-Z™: Cyber Security + Ethical Hacking

Explore the open systems interconnection model and its layered architecture, learning how encapsulation enables data to move across interoperable networks and how to troubleshoot using the layered approach.

Describe how the layered reference model structures computer communications into distinct layers, enabling binding and standardization to achieve interoperability, simpler design, and isolated, vendor-friendly development.

Explore the seven-layer open systems interconnection model, from application to physical, and see how top layers handle application communication while bottom layers manage end-to-end transfer, IP addressing, and Mac addressing.

Coordinate partner availability and resources at the application layer, enabling communication for file transfer, email, and remote access via the protocol stack.

explains the presentation layer's role in translating, formatting, and standardizing data for application, compression and encryption, and outlines session layer's duties in managing sessions and simplex to full duplex communication.

The transport layer segments and reassembles data into a stream, enabling end-to-end services, a logical host connection, connection-oriented multiplexing of applications, virtual connections, and supports tcp and udp.

Contrast connection oriented and connectionless transport services, explain virtual circuit setup, three-way handshake, and overhead, and show why connection oriented offers reliable data transfer.

Explore flood control and flow control at the transport layer to ensure reliable, connection oriented data transfer, using virtual circuits, sequencing, acknowledgements, and not ready indicators.

Explore how windowing in the transport layer controls data flow by using window size to send multiple data segments before acknowledgments, improving throughput and understanding flow control.

Explore the physical layer, which sends and receives bits, encodes data for media, and defines mechanical, electrical, and procedures for activating and deactivating a physical link, including DTE/DCE devices.

Recap the seven-layer model, its layer functions and encapsulation, then explore data link and physical layer duties, with switches, bridges, and routers explained for certification exams.

Explore network topologies and physical media, wiring cables, and wiring standards, as this section covers transceivers, media converters, and cable properties to prepare for exams.

Discover how coaxial cable serves as the physical media backbone, detailing its copper center conductor, dielectric, shield, and plastic jacket, plus plenum rating, NFPA requirements, and BNC connectors.

Analyze twisted pair cables, including shielded and unshielded variants, and how twisting minimizes crosstalk and interference. Examine Ethernet standards such as 100BaseX, 1000BaseX, and 10GBaseX to understand megabits-per-second transmission rates.

Fiber optic cable transmits digital signals as light, is immune to EMI, and uses glass or plastic with cladding and buffer; single mode and multimode fibers support long-distance, high-speed links.

Explore common media converters, including single-mode fiber to ethernet, multimode fiber to ethernet, and fiber to coaxial, and compare serial and usb connections to understand cable types and interfaces.

Explore the evolution of utp cable categories from cat 1 to cat 6e, including data rates and frequency ranges, and learn RJ-11/RJ-45 connectors and basic utp terminations.

Explore why network cables differ in speed and distance as you review wiring standards such as 568-a, 568-b, and 568-e, and learn straight-through and crossover cable concepts.

Learn how straight-through, crossover, and rollover cables connect hosts, switches, routers, and Cisco consoles. Understand pin mappings and 10/100 Ethernet limits.

Master networking cabling basics, including twisted pair and fiber, with coaxial usage limited; learn wiring standards, connectors (RJ-11, RJ-45, BNC), media converters, and crossover vs rolled-over cables.

Explore the basics of local area networks, ethernet fundamentals, ip addressing, and mac addresses, including collision and broadcast domains, baseband and broadband, and data link and physical layer implementations.

Explore Ethernet basics and the contention media access method that shares bandwidth. Learn how collision domains and broadcast domains shape traffic in hub, switch, and repeater environments.

Explore how CSMA/CD uses collision detection, jam signals, and a backoff algorithm to manage Ethernet access and prevent simultaneous transmissions on shared media.

Explore broadband and baseband concepts, including transmitting analog and digital signals via frequency division multiplexing, Ethernet in LANs, and the distinction between bitrate and baud.

Understand how binary digits and bits form numbers, learn binary-to-decimal conversion with examples like 128, 65, and 35, and preview hexadecimal and tcp/ip protocol fundamentals.

Explore the 48-bit MAC address, six hexadecimal octets with an IEEE 24-bit OUI. See how unicast versus multicast and local versus global bits indicate destination and administration.

Explore how Ethernet frames at the data link layer encapsulate network data into MAC frames, detailing preamble, addresses, length or type, data, and CRC for error detection.

Explore how Ethernet operates at the physical layer, from coaxial cable and twisted pair to fiber. Trace the evolution of IEEE 802.3 standards—from fast to gigabit to 10 gigabit Ethernet.

Explore IEEE 802.3 ethernet standards, including 10base-t, 100base-tx, and 1000base-t, and compare cabling like cat 3 and cat 5/6 with star topology.

Learn the fundamentals of internet networking, including how hosts communicate on local area networks with hardware addresses, and understand internet addressing in hex and binary, plus common networking devices.

Define cybersecurity as using technologies and controls to defend computer systems, networks, and data from malicious attacks, and distinguish it from broader information security.

Identify core cybersecurity types, including network security, application security, system security, physical security, personal security, organizational security, secure code development, and cloud security, to protect data across organizations.

Trace the history of cybersecurity from the 1960s security basics to today’s defenses, including ARPANET origins, the Morris worm, firewalls, and major breaches like Yahoo and a 2017 ransomware attack.

Explore essential cybersecurity terms such as information security, confidentiality, integrity, availability, threats, vulnerabilities, risk management, cryptography, encryption, hashing, VPNs, firewalls, and authentication.

Identify, quantify, and prioritize security weaknesses through vulnerability assessments conducted by ethical hackers to remediate vulnerabilities and defend against threats like cross-site scripting and code injection.

Identify and score vulnerabilities across hardware and software assets, including coding errors, missed configurations, and input validation failures, to reveal weaknesses early and prevent exploits like eternal blue.

Master ten steps of vulnerability assessment: obtain legal authorization, define scope, gather information, use automated and manual testing, gain access, escalate privileges, report findings, patch, and revalidate with a team.

Discover why cybersecurity matters as internet use expands, safeguarding data from cyberattacks and breaches and protecting confidential information across banking, healthcare, and education in a connected world.

Explore major information security organizations and certifications, including Women in cybersecurity, SANS, OWASP, ISSA, FIRST, ISC Square, ISACA, EC-Council, CompTIA, and privacy professionals.

Penetration testers help organizations identify security weaknesses in information systems and networks, requiring networking knowledge, scripting, and strong reporting skills to communicate findings to management.

Explore the role of information security analysts who monitor, prevent, and respond to data breaches by building firewalls, encrypting data, and strengthening network security.

Explore the security consultant role as a security auditor who analyzes threats, oversees solutions, and communicates findings to clients using cloud computing, certifications, and critical thinking.

Explore the chief information security officer, the heart and brain of the security team, who leads cloud identity and access management, communication, and strategic leadership to protect the organization.

Explore what a virtual machine is and why we need it. Compare hardware-based and software-based virtual machines, and discover uses like testing, running different operating systems, and creating portable appliances.

Install and configure virtual box on a Windows machine, download the latest version, install the extension pack for USB and encryption support, and complete the setup as administrator.

Download and install Kali Linux from the official source, import the virtual image in VirtualBox, configure network and settings, and boot to explore information gathering and vulnerability assessment tools.

Download and install the Lapps broken application in VirtualBox, import the labs, configure the NAT network, start the machine, and locate its IP to begin penetration testing.

Install DVWA on Kali Linux by cloning the repo, setting permissions, and configuring the database and Apache; access 127.0.0.1/dvwa with admin credentials to practice vulnerabilities.

Install Metasploitable on VirtualBox by downloading the image, creating the VM, and configuring networking for a vulnerable, hands-on practice.

Practice basic Linux commands for ethical hacking in Kali Linux using the terminal. Explore navigating directories, creating folders, listing contents, and copying files with permissions in mind.

Master advanced Kali Linux commands for ethical hacking, including mv, touch, rm, nano, cat, passwd, useradd, userdel, and chmod for file operations, user management, and permissions.

Explore how web servers store, run, and deliver web pages to clients, including URL resolution, DNS lookup, IP addresses, and the role of the browser and server software.

Understand why web servers are compromised through misconfigurations, default credentials, and unnecessary services, and gain an overview of attacks like denial of service, hijacking, traversal, man-in-the-middle, and defacement.

Perform methodical web server pentesting to identify authentication weaknesses, misconfigurations, and protocol vulnerabilities, using information gathering, fingerprinting, directory enumeration, and vulnerability scanning to document and remediate findings.

Explore countermeasures for web servers, including DMZ design, firewalls, patch management, backups, secure remote access, least-privilege access, intrusion detection, certificate management, secure coding, and restricted access to databases.

Master information gathering and reconnaissance to collect target data through passive and active footprinting, mapping networks, domains, and systems, using search engines and social engineering to reveal vulnerabilities.

Leverage Maltego in Kali Linux to perform information gathering and reconnaissance, visualize open-source intelligence, and identify server technologies, domain name schema, and contact details.

Explore information gathering with Maltego in Kali Linux to map domains, mail servers, DNS, IP addresses, and geographical location.

Learn how to clone a website offline with HTTrack, mirroring a target to a local system to analyze directories, files, images, and videos for ethical hacking and pen testing.

Explore open source intelligence with the osint framework, a web-based toolset for data collection, reconnaissance, and classification of information resources for ethical hacking.

Learn to use the open source redhawk information gathering tool on Linux to detect cms, identify ip and web server details, and perform whois, dns, and subdomain lookups.

Explore the first five OWASP top ten web application vulnerabilities: injections, broken authentication, sensitive data exposure, XML external entity attacks, and broken access control.

Continue exploring the remaining OWASP top 10 attacks, including misconfiguration vulnerabilities, parameter tampering, improper error handling, insecure deserialization, using components with known vulnerabilities, cross-site scripting, and insufficient logging.

Master website footprinting with whois queries to uncover domain and IP data. Use builtwith and SSL certificate insights to identify technologies for pentesting.

Explore website footprinting with web archives, DNS, and web crawlers, and see how the Wayback Machine captures site snapshots from 1997 to 2020, illustrating changes over time.