You want to be successful in computer networking. What’s the first thing you need to know?

1 OSI Model

The Open Systems Interconnection (OSI) model is a theoretical framework that describes how data flows from one device to another across a network. It consists of seven layers, each with a specific function and protocol. The OSI model helps you understand the roles and responsibilities of each layer, as well as how they interact and cooperate with each other. The OSI model is not a standard, but a reference tool that can help you learn and compare different network technologies.

2 TCP/IP Model

The Transmission Control Protocol/Internet Protocol (TCP/IP) model is a practical and widely used network model that defines how data is transmitted over the internet and other networks. It consists of four layers, each with a set of protocols that govern the communication and data exchange between devices. The TCP/IP model is a standard that enables interoperability and compatibility among different network devices and applications. The TCP/IP model is based on the OSI model, but it simplifies and consolidates some of the layers and functions.

3 Network Topologies

Network topologies refer to the physical and logical arrangements of network devices and connections. They affect the performance, reliability, and security of a network. There are different types of network topologies, such as star, bus, ring, mesh, tree, and hybrid. Each topology has its own advantages and disadvantages, depending on the size, scope, and purpose of the network. Network topologies can also be classified as LAN (local area network), WAN (wide area network), MAN (metropolitan area network), or PAN (personal area network), depending on the geographic range and scale of the network.

4 Network Devices

Network devices are the hardware components that enable data transmission and reception across a network. They perform various functions, such as routing, switching, firewalling, load balancing, and proxying. Some of the common network devices are routers, switches, hubs, bridges, repeaters, firewalls, load balancers, proxies, and modems. Each device has its own specifications, features, and capabilities, depending on the network layer and protocol it operates on. Network devices can be configured and managed using different methods, such as command-line interface (CLI), graphical user interface (GUI), or web-based interface.

5 Network Protocols

Network protocols are the rules and conventions that govern the communication and data exchange between network devices and applications. They define the format, structure, syntax, and semantics of the data packets, as well as the procedures and algorithms for error detection, correction, and recovery. There are hundreds of network protocols, each with a specific purpose and function. Some of the common network protocols are TCP, IP, UDP, HTTP, FTP, SMTP, DNS, DHCP, ARP, ICMP, and SSL/TLS. Network protocols can be classified into different categories, such as transport, application, routing, or security protocols, depending on the network layer and function they belong to.

6 Network Security

Network security is the process and practice of protecting network devices, data, and applications from unauthorized access, modification, or destruction. Network security involves both technical and human aspects, such as encryption, authentication, authorization, auditing, monitoring, and awareness. Network security is essential for ensuring the confidentiality, integrity, and availability of network resources and services. Network security can be implemented using different techniques, such as firewalls, VPNs, IDS/IPS, antivirus, encryption, and certificates.