# Internet Fundamentals/Networking

This lesson introduces networking fundamentals, including network devices, Internet protocols, and name resolution.

## Objectives and Skills

Objectives and skills for this lesson include:
* Identify the infrastructure required to access the Internet, including hardware and software components.
* Define important Internet communications protocols and their roles in delivering basic Internet services.
* Identify the basic principles of the Domain Name System (DNS).

## Readings

* Wikipedia: Computer network
* Wikipedia: Internet protocol suite
* Wikipedia: Domain Name System
* Wikibooks: Introduction to Computer Information Systems/Computer Networks

## Multimedia

* YouTube: Computer Networks - Crash Course
* YouTube: The Internet: IP Addresses and DNS
* YouTube: The Internet: Packets, Routing and Reliability
* YouTube: How does the INTERNET work?
* YouTube: DNS Explained
* YouTube: The OSI Model Demystified
* YouTube: IT Fundamentals - Basic Networking Devices
* YouTube: Introduction to Computer Networks Part 1 - Easy to understand basics
* YouTube: Introduction to Computer Networks Part 2 - Easy to understand basics
* YouTube: Introduction to Computer Networks Part 3 - Easy to understand basics
* YouTube: Installing a SOHO Network

## Activities

* Complete the following tutorials:
** TutorialsPoint: Internet Reference Models
** TutorialsPoint: Internet Protocols
** TutorialsPoint: Internet Domain Name System
* Review IP address settings for your local network:
** Windows:
*** Review Microsoft: How do I fix network adapter problems? and Microsoft: Change TCP/IP Settings. Review network settings for your system.
*** Review ipconfig. Complete the activities to display IP address information, all information, and release and renew a dynamic IP address.
** macOS:
*** Review Apple: About Network Utility. Use Network Utility to review network settings for your system.
*** Review MacWorld: Configuring Your Mac's Network Settings Use System Preferences / Network to review network settings for your system. Use the Advanced button and TCP/IP settings to renew your DHCP lease.
*** Review Wikipedia: ifconfig. Use ifconfig to review network settings for your system.
** Linux:
*** Review YoLinux: Network GUI Configuration Tools. Use Network Configuration or System Settings / Networking to review network settings for your system.
*** Review Wikipedia: ifconfig. Use ifconfig to review network settings for your system. Review CyberCiti: Linux Force DHCP Client to Renew IP Address. Use dhclient to release and renew a dynamic IP address.
* Verify Internet connectivity:
** Verify a physical connection:
*** Wired: Check for connectivity lights on the network adapter and switch or router.
*** Wireless: Check for connectivity through the user interface.
** Verify ip address settings.
*** Windows: Use ipconfig.
*** macOS: Use Network Utility, System Preferences / Network, or ifconfig.
*** Linux: Use Network Configuration, System Settings / Networking, or ifconfig.
** Review Ping/Host. Verify local and remote connectivity using ping.
*** Ping your local IP address.
*** Ping your local default gateway address.
*** Ping an Internet host such as 8.8.8.8.
** Review Tracert. Trace the route to an Internet host such as 8.8.8.8.
** Use https://traceroute-online.com/ to visually trace the route to en.wikiversity.org or another host.
** Review Nslookup. Verify name resolution using nslookup and an Internet host name, such as en.wikiversity.org.
* Share a folder and connect to the shared folder:
** Windows GUI:
*** Review Microsoft: File Sharing Essentials. Share a folder on your system.
*** From another computer, use a UNC path to connect to the shared folder.
** Windows CLI:
*** Review Microsoft: Net Share. Use the net share command to share a folder on your system.
*** Review Microsoft: Net Use. From another computer, use the net use command to connect to the shared folder.
** macOS:
*** Review Apple: Mac Basics: File Sharing. Share a folder on your system.
*** Review Apple: Connect to Shared Computers and File Servers on a Network. From another computer, connect to the shared folder.
** Linux:
*** Review TechGage: Using Samba to Share Your Linux Folders. Install Samba if necessary and share a folder on your system.
*** Review HowToGeek: 3 Easy Ways to Connect to Windows Shared Folders from Linux. From another computer, connect to the shared folder.
* Research and compare license and support costs for Windows, macOS, and Linux.
* Research plans available from different wired (cable, DSL) and wireless (cellular, wireless, satellite) Internet providers. Compare mobility, availability, bandwidth, reliability, delay, concurrent connections, security, and cost.
* Research, identify and describe the necessary components required to set-up a home network for yourself.

## Lesson Summary

* A computer network or data network is a digital telecommunications network that allows computers to exchange data. Networked computing devices pass data to each other in the form of packets across connections established using either cable or wireless media.
* A network packet is a formatted unit of data sent through a network to the destination. Once packets arrive, they are reassembled into their original message.
* Wired media includes coaxial cable, twisted-pair cable, and optical fiber.
* Wireless local area network connections use spread spectrum technology based on a common flavor of open-standards wireless radio-wave technology defined as IEEE 802.11 and known as Wi-Fi.
* A network interface controller (NIC) is hardware that provides a computer with the ability to access the transmission media, and has the ability to process low-level network information.
* In Ethernet networks, each NIC has a unique 48-bit Media Access Control (MAC) address.
* A repeater or hub is an electronic device that receives a network signal in the form of bits, cleans it of unnecessary noise, and regenerates it. In local area networks, switches have replaced hubs.
* A bridge or switch is a device that connects and filters multiple network segments or devices, by forwarding data only to one or multiple devices that need to receive the data based on destination MAC address.
* A router is a device that forwards data packets between different computer networks based on network address (IP address).
* A modem is a device used to connect network nodes via wire not originally designed for digital network traffic, by modulating the digital signal to produce an analog signal for transmission.
* A firewall is a device used to control network security and access rules by rejecting access requests from unrecognized sources while allowing actions from recognized ones.
* Network topology is the layout or organizational hierarchy of interconnected nodes of a computer network. Common topologies include bus, star, ring, and mesh.
* A communications protocol is a set of rules for exchanging information over a network. In a protocol stack, each protocol leverages the services of the protocol below it.
* An important example of a protocol stack is HTTP (the World Wide Web protocol) running over TCP over IP (the Internet protocols) over IEEE 802.11 (the Wi-Fi protocol).
* Participants in the Internet use a diverse array of methods of several hundred documented, and often standardized, protocols compatible with the Internet Protocol Suite and an addressing system (IP addresses) administered by the Internet Assigned Numbers Authority and address registries.
* A network can be characterized by its physical capacity or its organizational purpose. These include personal area network (PAN), local area network (LAN), and wide area network (WAN).
* A virtual private network (VPN) is an overlay network in which some of the links between nodes are carried by open connections or virtual circuits in some larger network instead of by physical wires.
* An intranet is a set of networks that are under the control of a single administrative entity.
* An extranet is a network that is under the administrative control of a single organization, but supports a limited connection to a specific external network.
* Routing is the process of selecting network paths to carry network traffic.
* Network services are applications hosted by servers on a computer network, to provide some functionality for members or users of the network, or to help the network itself to operate.
* Network security consists of provisions and policies adopted by the network administrator to prevent and monitor unauthorized access, misuse, modification, or denial of the computer network and its network-accessible resources.
* The Internet protocol suite is the set of communications protocols used for the Internet and similar networks.
* The Internet protocol suite is a four-layer model containing Link, Internet, Transport, and Application layers.
* The Internet protocol suite is maintained by the Internet Engineering Task Force (IETF).
* The Link layer contains communication technologies for a local network.
* The Internet layer connects local networks, thus establishing internetworking.
* The Transport layer handles host-to-host communication.
* The Application layer contains all protocols for specific data communications services on a process-to-process level.
* The Domain Name System (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network.
* The Domain Name System translates more readily memorized domain names to the numerical IP addresses needed for locating and identifying computer services and devices with the underlying network protocols.
* The Domain Name System delegates the responsibility of assigning domain names and mapping those names to Internet resources by designating authoritative name servers for each domain. Network administrators may delegate authority over sub-domains of their allocated name space to other name servers.
* The domain name space consists of a tree data structure. Each node or leaf in the tree has a label and zero or more resource records (RR), which hold information associated with the domain name.
* The domain name itself consists of the label, possibly concatenated with the name of its parent node on the right, separated by a dot.
* The domain name tree sub-divides into zones beginning at the root zone. The right-most label conveys the top-level domain.

## Key Terms
### 4G

    The fourth generation of mobile telecommunications technology.

### address

    A numerical designation that uniquely refers to a specific communication entity.

### backbone

    A part of computer network that interconnects various pieces of network, providing a path for the exchange of information between different LANs or subnetworks.

### bandwidth

    The bit-rate of available or consumed information capacity expressed typically in metric multiples of bits per second.

### client

    A piece of computer hardware or software that accesses a service made available by a server.

### DARPA

    An agency of the U.S. Department of Defense responsible for the development of emerging technologies for use by the military.

### domain name

    An identification string that defines a realm of administrative autonomy, authority or control within the Internet.

### DSL (Digital Subscriber Line)

    A family of technologies that are used to transmit digital data over telephone lines.

### frame

    A digital data transmission unit in computer networking and telecommunication.

### FQDN (Fully Qualified Domain Name)

    A domain name that specifies its exact location in the tree hierarchy of the Domain Name System (DNS).

### gateway

    A piece of networking hardware equipped for interfacing with another network that uses different protocols.

### host

    A computer or other device connected to a computer network.

### IANA (Internet Assigned Numbers Authority)

    A department of ICANN, a nonprofit private American corporation that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System, media types, and other Internet Protocol-related symbols and Internet numbers.

### IP (Internet Protocol)

    The principal communications protocol in the Internet protocol suite for relaying datagrams across network boundaries.

### ISP (Internet Service Provider)

    An organization that provides services accessing and using the Internet.

### packet

    A formatted unit of data carried by a packet-switched network.

### protocol

    A system of rules that allow two or more entities of a communications system to transmit information via any kind of variation of a physical quantity.

### proxy server

    A server that acts as an intermediary for requests from clients seeking resources from other servers.

### server

    A computer program or a device that provides functionality for other programs or devices.

### TCP (Transmission Control Protocol)

    One of the main protocols of the Internet protocol suite; It provides reliable, ordered, and error-checked delivery of a stream of bytes between applications running on hosts communicating by an IP network.

### TLD (Top-Level Domain)

    One of the domains at the highest level in the hierarchical Domain Name System of the Internet.

### throughput

    The rate of successful message delivery over a communication channel.

### wireless access point

    A networking hardware device that allows a Wi-Fi device to connect to a wired network.

## Assessments

* Crossword Puzzle: Crossword Basic Networking Terms

## See Also

* IC3/Network Fundamentals
* IT Fundamentals/Networking
* Networking Guides: Setting Up a Home Network