This article explains the evolution from OSI to TCP/IP models, details the structure and allocation ranges of IPv4 class A‑E addresses, compares network and host portions, introduces subnet masks, CIDR notation, and the relationship between IP and hardware (MAC) addresses.
This article explains the 48‑bit MAC address format, IEEE allocation rules, address block sizes, how to modify MAC addresses on Linux and macOS, and the role of MAC addresses in Ethernet frames, ARP, and LAN communication, highlighting practical considerations and limitations.
A college student recounts turning a single Ethernet cable into a makeshift network switch, unintentionally creating a VLAN broadcast storm that exposed the mechanics of Ethernet loops, STP detection, and the challenges of covertly controlling a dormitory LAN.
This article explains the difference between public and private IP addresses, details the IPv4 class A‑E ranges, describes why private networks often use 192.168.x.x, and introduces NAT as the mechanism that maps internal addresses to external ones for internet access.
This article presents a comprehensive collection of 100 essential networking concepts, covering topics such as links, OSI model layers, backbone, LAN, routers, subnet masks, VPN, NAT, TCP/IP, security measures, cabling, topologies, protocols, and many other foundational terms that every network professional should know.
This article explains the fundamentals of IP addressing, detailing how network and host IDs identify devices, the classification of IP addresses into classes A through E, their binary prefixes and numeric ranges, and introduces subnetting concepts such as subnet masks and dividing networks into smaller segments.
Using a quirky long-distance video-chat scenario, the article illustrates how TCP’s three-way handshake and four-way termination work, explains the purpose of each packet exchange, details TCP header fields, and even covers SYN-flood attacks, turning everyday communication glitches into networking fundamentals.
The article explains the complete exhaustion of the global IPv4 address pool, outlines the key dates when regional registries ran out of addresses, and highlights how IPv6's massive address space and technical advantages are essential for the future of the Internet and IoT.
The article explains the complete exhaustion of the 4.3 billion IPv4 addresses, outlines the timeline of the last allocations by regional registries, and highlights IPv6’s massive address space and security benefits as the essential solution for the future internet and IoT growth.
This guide explains how to manually configure IP addresses using ifconfig or ip commands, the role of DHCP in dynamic IP allocation, and how PXE leverages DHCP to automate OS installation, covering packet flow, ARP handling, lease renewal, and boot processes.
This article explains the basic concepts of network switches, including data link layer functions, MAC address structure, unicast and multicast addressing, Ethernet II frame composition, common switch models, and the forwarding principles illustrated with diagrams.
This guide explains the concepts of routing tables, static and default routes, and provides step‑by‑step Cisco router configuration commands and verification procedures to achieve full network connectivity between two routers and their attached PCs.
This article explains the basic definition of computer networks, their main functions, the evolution from early LANs and WANs to the modern Internet, and introduces core concepts such as protocols, standards, and the four historical development stages of networking technology.
This article explains the purpose and binary composition of IPv4 addresses, details class A‑E ranges, private address blocks, subnet masks, and provides step‑by‑step router configuration commands to establish network connectivity.
This article explains how OSPF avoids routing loops by using various LSA types—Type‑1, Type‑2, Type‑3, Type‑4, and Type‑5—and the role of ABRs, backbone requirements, and SPF calculations in maintaining a loop‑free network topology.
This article explains DNS fundamentals, the impact of incorrect local DNS on user experience, outlines recursive and authoritative DNS roles, describes domain hierarchy, and provides a practical overview of BIND server setup, its configuration files, and sample zone definitions with dig query results.
This article provides a comprehensive reference of the 65535 TCP/UDP ports, detailing the most frequently used ports, their associated services, typical vulnerabilities, and the specific ports commonly used by proxy servers, helping readers quickly identify and troubleshoot network and security issues.
This article explains the problems of layer‑2 loops and broadcast storms, how VLAN segmentation and spanning‑tree protocols mitigate them, and introduces TRILL technology for scalable data‑center networks, providing detailed concepts, mechanisms, and practical examples for network engineers.
This comprehensive guide walks you through the core concepts of computer networking, including the OSI and TCP/IP models, detailed explanations of TCP and UDP protocols, HTTP fundamentals, socket programming, IP addressing, ICMP, ping operations, and the differences between routers, switches, cookies, sessions, and tokens.
This article introduces the basic concepts, structure, advantages, key devices, and current and future transmission techniques of optical communication, explaining how light‑based networks enable long‑distance, high‑capacity, and fast data transfer worldwide.
This article explains the TCP header layout, details each field and control flag, and walks through the three‑way handshake for connection establishment and the four‑step termination process, including why these specific numbers of steps are required and the purpose of the 2 MSL wait.
This article explains the TCP connection process, detailing socket creation, the roles of send and receive buffers, the functions socket(), bind(), listen(), accept(), and how address/port reuse and SYN flood mitigation affect performance and reliability.
This article explains DNS fundamentals, detailing how domain names are resolved to IP addresses, the multi‑step query process shown with the dig tool, the hierarchical server architecture, record types, and additional utilities, enabling readers to fully understand and troubleshoot DNS operations.
The article uses the analogy of heavy rain flooding to explain network flooding and broadcast storms, describing how Ethernet switches handle unknown frames, why loops cause endless broadcast traffic, and how VLAN segmentation and spanning‑tree protocols mitigate these issues in modern data‑center architectures.
This guide outlines the fundamental concepts, mindset, and step‑by‑step skills needed for beginners to start learning hacking and information security, covering everything from basic network knowledge to legal considerations.
This guide demonstrates how to configure interfaces and static routes on three Cisco routers (R1, R2, R3) using CLI commands, assign IP addresses, enable interfaces, and verify the routing table, providing a step‑by‑step example of basic network routing setup.
This article explains the TCP three-way handshake and four-way termination processes, detailing each packet exchange, state transition, and the reasons why these mechanisms are essential for reliable network communication.
