Networking Basics and Concepts

• Introduces basic networking concepts, architecture, terminology, and common network devices.
• Assumes familiarity with basic computer software/hardware and limited network exposure.
• Skills covered include defining network concepts, cloud/virtualization, and remote access methods.

Defining Network Concepts

• A network consists of two or more electronic devices sharing information over interconnected media.
• Each device has a unique MAC or IP address for identification on the network.
• The Internet is a collection of interconnected networks.
• Devices communicate using bits and bytes, transmitted serially.
• Shared networks require devices to take turns sending data in small chunks called frames or packets.
• Multiple access protocol is a technique of sharing a common media among many devices.

Network Protocols

• Protocols are sets of rules that define network behavior, covering hardware and software.
• Protocols ensure interoperability between devices from different manufacturers.
• Common protocols include IP, TCP, and Ethernet.

Internet Structure

• The Internet is a global network of interconnected local networks.
• Access providers connect homes/offices to the internet.
• Service providers aggregate traffic from access provider locations.
• Backbone providers offer long-haul, high-speed infrastructure.
• The Internet Engineering Task Force (IETF) provides protocols and standards.
• The World Wide Web (Web) is a way of accessing information on the internet using the HTML protocol and web browsers.

Intranet and Extranet

• Intranet is an organization's private network accessible only to authorized members with limited external access.
• Extranet is an intranet with expanded access for external organizations, restricted to selected users with login credentials.

Client-Server vs. Peer-to-Peer

• Peer-to-peer networks allow any device to communicate with any other, without hierarchy.
• Client-server involves a client requesting services from a server; common on the internet.
• Client-side software resides on the end-user device, while server-side software is on a server at a service provider.

Transmission Types

• Unicast transmission sends data to one specific address (one-to-one).
• Multicast transmission sends data to multiple nodes simultaneously (one-to-many)
• Broadcast transmissions sends a message to every device on a network (one-to-all).

Network Devices and Ethernet

• A network node is any connected device.
• Network hardware (switches, routers, bridges) enables network operation.
• Application hardware constitutes "user" devices (computers, printers, etc.)
• Ethernet is a family of networking technologies for LANs, defining hardware and data transmission.
• Network switches connect individual network nodes and route data.
• Network routers route traffic between networks.
• Bridges connect different physical media.

Internet of Things (IoT)

• IoT refers to the growing number of electronic devices communicating peer-to-peer over the Internet.
• IoT devices have created interoperability and security challenges.

Cloud Computing

• Cloud refers to something (software, hardware) residing at a distant, unknown location on the internet.
• Cloud computing involves running and accessing application software on a remote computer which has several advantages:
  • Not needing to own, install, or maintain the software.
  • Being able to access the software from anywhere with an internet connection.
  • Data being stored on remote servers with access granted to other co workers
• If there is no internet then files are not accessible, there are also potential security risks

Virtualization

• Virtualization emulates a hardware environment in software to fake a hardware environment to other software.
• Virtual machines (VMs) run operating systems within an application, behaving like independent computers.
• It allows multiple applications/users to share hardware resources, improving processor time utilization.

Hypervisors

• Hypervisors are specialized software that enables a host computer to support multiple VMs simultaneously.
• They isolate operating systems/applications from hardware and manage shared resources.
  • Type 1 hypervisors run directly on the host system ("bare metal").
  • Type 2 hypervisors run as an application on the native OS ("hosted").

Network Virtualization

• Network virtualization extends the virtual machine concept to network components.
• Virtual NIC cards and switches can be implemented in software.
• Virtualizing networks (SDN) allows easier configuration, upgrade, and maintenance.

Virtual Private Networks (VPNs)

• A VPN creates a private, secure, encrypted connection over the Internet to conceal the identity and activity of the device.
• VPNs rely on IPsec and provide authentication, integrity, and confidentiality.
• VPN software creates a secure connection, encrypts data, and encapsulates it within a non-encrypted packet for tunneling.
• VPNs facilitate remote workers becoming part of the office, with access to printers and files.
• VPN communications can run on a single computer, a router or a site-to-site network
• VPN service providers provide encrypted and secure connections from any location
• The extra encryption and tunneling adds overhead that can slow everything down
• Compatibility issues can emerge as VPN software from different manufacturers can all have different algorithms which affect speeds

Remote Desktop

• Remote desktop software allows controlling a computer in another location over a network.
• It uses Remote Desktop Protocol (RDP) to display the remote screen and control it.
• There are two major categories of remote desktop software: operating system-based and third-party solutions.
• RDP encrypts data for secure connections.
• The delay can cause slow keystrokes, transmitted mouse movements, and desktop displays