Introduction to Networking & TCP/IP PDF

NI L E Introduction to C T Networking U Networking Infrastructure R E Diploma in CSF Year 1 (2024/25), Semester 2 1  Official (Closed) - Non Contents Sensitive Definition of a Computer Network Local Area Network (LAN), Wirel...

NI L E Introduction to C T Networking U Networking Infrastructure R E Diploma in CSF Year 1 (2024/25), Semester 2 1  Official (Closed) - Non Contents Sensitive Definition of a Computer Network Local Area Network (LAN), Wireless LAN & Wide Area Network Networking Hardware Components Client and Server Communication How a Browser communicates with a Web Server? Encapsulation & De-encapsulation 4-Layer & 5-Layer TCPIP Protocol Suite Slide 2 Last update: Dec 10, 2024  Official (Closed) - Non Definition of a Computer Network (Recap CSF – Slide 3 to 15) Sensitive A network is a set of technologies used to connect computers together, to allow them to communicate and share resources e.g. files and printers A typical network is a Local Area Network (LAN); a network device such as Switch provides connection ports for computers and devices to be attached using cables Switch 3 A LAN spans a small geographic area such as a home, a floor within a building, a single building or multiple buildings in a campus. Slide 3 Last update: Dec 10, 2024  Official (Closed) - Non Definition of a Computer Network – cont’d Sensitive Wireless LAN (WLAN) allows devices to connect using a wireless Access Point (AP) without using cables (wired connections) This wireless AP can be connected to a switch using a cable, forming a larger LAN. Wireless LAN LAN Switch File / Application Server 4 Slide 4 Last update: Dec 10, 2024  Official (Closed) - Non Definition of a Computer Network – cont’d Sensitive Interconnected LANs/networks that span across wide geographical locations form a Wide Area Network (WAN). For a switch to connect to the WAN/Internet i.e. LAN to WAN, it requires a networking device called a Router (or Gateway). LAN WAN Wireless LAN WAN Switch connection Router Server Slide 5 Last update: Dec 10, 2024  Official (Closed) - Non Networking Hardware Components Sensitive In a typical LAN, the networking hardware components are: - A network device (interconnecting device), typically a switch - A network adapter or network interface controller (NIC) for each computer/device. - Network cables to connect computers/devices to the switch. Ethernet Switch (Network UTP Cable with an cable: unshielded twisted pair (UTP) cable with (Network an RJ45 Device) RJ45 Connector at connectoreach on end each end used for wired connection) 6 NIC Slide 6 Last update: Dec 10, 2024  Official (Closed) - Non Networking Hardware Components – cont’d Sensitive Network Interface Controller (NIC) – for wired LAN It provides LAN connectivity It can be a card or built into the motherboard; it can also be an external adapter 7 USB Ethernet UTP cable Adapter RJ45 connector Slide 7 Last update: Dec 10, 2024  Official (Closed) - Non Networking Hardware Components – cont’d Sensitive In a wireless LAN, the hardware components are: - wireless Access Point (AP) - wireless network adapter or Wi-Fi adapter (can be a card or built-in on the motherboard; can also be an external adapter; it transmits and receives radio waves to/from AP) 8 Slide 8 Last update: Dec 10, 2024  Official (Closed) - Non Network Hardware Devices - Summary Sensitive Network hardware devices (or interconnecting devices) Switch connects devices to form a LAN Wireless AP connects devices to form a wireless LAN Router (or gateway) routes data on the LAN to the Internet (WAN) Optical Network Terminal (ONT) or Modem connects the router to the Internet via the WAN connection Wireless WAN Access Point Switch Router ONT/Modem WAN connection Slide 9 Last update: Dec 10, 2024  Official (Closed) - Non Home Network Hardware Devices Sensitive In home and small office networks, the Router, the Switch and the Wireless Access Point could be integrated into one unit called the Wireless Router (or Residential Gateway). Wireless WAN Access Point Switch Router ONT/Modem WAN connection Wireless Router (Residential Gateway) Slide 10 Last update: Dec 10, 2024  Official (Closed) - Non Home Network Hardware Devices – cont’d Sensitive For a typical home network using optical fibre connection, the Internet Service Provider (ISP) usually provides: - Optical Network Terminal (ONT) - Wireless Router (or Residential Gateway) Wireless Router (Residential Gateway) ONT Optical Fibre Connection Slide 11 Last update: Dec 10, 2024  Official (Closed) - Non Home Network Hardware Devices – cont’d Sensitive For newer installations, ISP may provide an Optical Network Router (ONR). Switch Router ONT Optical Network Connection Optical Network Router (ONR) Note: Wireless AP may also be integrated into the ONR Slide 12 Last update: Dec 10, 2024  Official (Closed) - Non MAC Addressing Sensitive  To allow devices to communicate within a LAN, each of them has an address called media access control (MAC) address.  It is also known as physical address (burnt-in to the NIC or Adapter). 13 Slide 13 Last update: Dec 10, 2024  Official (Closed) - Non MAC Addressing – cont’d Sensitive  You can find your device’s MAC/Physical address by typing the command at the command prompt: ipconfig /all 14 Slide 14 Last update: Dec 10, 2024  Official (Closed) - Non IP Addressing Sensitive  While MAC address identifies devices within a LAN, an IP address identifies each device connected to the Internet.  You can find your device’s IP address using the command at the command prompt: ipconfig /all or ipconfig 15 Slide 15 Last update: Dec 10, 2024  Official (Closed) - Non Activity 1: MAC & IP Address Sensitive From your laptop, start command prompt.  Type the command: ipconfig /all and write down:  Physical & IPv4 address of Wireless LAN adapter 10.1.131.106  Physical & IPv4 address of LAN/Ethernet adapter (if available on your laptop) 192.168.29.1 Type the command: ping ip_address (IP address of the Wireless LAN adapter on your classmate’s laptop)  If the “Destination host unreachable”, ask your classmate to “turn off” the Windows Defender Firewall on the laptop and try again  Remember to “turn on” the firewall after the activity  Note: Windows Defender Firewall is a host firewall on your laptop. Slide 16 Last update: Dec 10, 2024  Official (Closed) - Non Client-Server Communication Model Sensitive  In client-server model (or architecture), any process can act as Server or Client  It describes how a server process provides resources and/or services to one or more client processes. Example: - web server and - web client Slide 17 Last update: Dec 10, 2024  Official (Closed) - Non Examples of Server Services Sensitive Some examples of Server services: Each type runs software specific to its purpose: Web server - Apache HTTP Server, Microsoft IIS FTP server – Filezilla Many different server services can be installed on a single hardware server device. Slide 18 Last update: Dec 10, 2024  Official (Closed) - Non Examples of Client Software Sensitive When you retrieve a web-page using Google Chrome, Microsoft Edge, or Firefox, these different browsers are referred to as Web Client. FileZilla Client is the FTP Client that allow you to transfer file to and from the FTP Server. Similarly, Outlook is the e-mail client software that you use to retrieve e-mail from a mail server (Microsoft Exchange Server). Same as the hardware server, many different client software can be installed on a notebook or desktop, i.e. hardware client device. Slide 19 Last update: Dec 10, 2024  Official (Closed) - Non How a Browser communicates with a Web Server? Sensitive Application Application Layer Layer Transport Transport Layer Layer Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 Each computer has 4 protocol layers. The two computers are connected to the same network. Each computer has an IP Address and a MAC Address. Slide 20 Last update: Dec 10, 2024  Official (Closed) - Non Data Encapsulation Sensitive Application Application Layer Layer Transport Transport Layer Data Layer Encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 The data is encapsulated with a protocol header as it moves down the layers, a trailer is also added at the Network Interface Layer… Slide 21 Last update: Dec 10, 2024  Official (Closed) - Non Data Encapsulation Sensitive Application Application Layer Message Layer Transport Transport Layer Segment Layer Internet Packet Internet Layer Layer Network Interface Layer Frame Network Interface Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 Protocol Data Unit (PDU) is the basic unit of information exchanged between entities at each layer e.g. PDU for Internet layer is Packet. Slide 22 Last update: Dec 10, 2024  Official (Closed) - Non Data Encapsulation Sensitive Application Application Layer Layer Transport Transport Layer Layer Internet Internet Layer Layer Network Interface Layer Frame Network Interface Layer 001010010100100010101000110… 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 At the Network Interface Layer, the Frame is encoded into ‘0’ and ‘1’ and sent to the transmission medium… Slide 23 Last update: Dec 10, 2024  Official (Closed) - Non Frame Header Sensitive Source: https://en.wikipedia.org/wiki/Ethernet_frame Slide 24 Last update: Dec 10, 2024  Official (Closed) - Non Data De-encapsulation Sensitive https://www.youtube.com/watch?v=ntVii_EJc6s Application Application Layer Layer 35555 80 Transport Transport Layer Layer Internet Internet Layer Layer Network Interface Network Interface Layer Frame Layer 001010010100100010101000110… 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 The Network Interface Layer will check if the frame belongs to itself and thereafter check for errors … Slide 25 Last update: Dec 10, 2024  Official (Closed) - Non Data De-encapsulation Sensitive Application Application Layer Layer 35555 80 Transport Transport Layer Layer Data De-encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 The Headers and Trailer are removed and the data is passed on to the Internet layer. Slide 26 Last update: Dec 10, 2024  Official (Closed) - Non IP Header Sensitive Source: http://intronetworks.cs.luc.edu/1/html/ipv4.html Slide 27 Last update: Dec 10, 2024  Official (Closed) - Non Data De-encapsulation Sensitive Application Application Layer Layer 35555 80 Transport Transport Layer Layer Data De-encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 At the IP layer, if the IP address is belong to the computer, the IP Header is removed and the data is passed on to the Transport layer. Slide 28 Last update: Dec 10, 2024  Official (Closed) - Non TCP Header Sensitive 35555 80 slide29 Source: http://intronetworks.cs.luc.edu/1/html/tcp.html Slide 29 Last update: Dec 10, 2024  Official (Closed) - Non Data De-encapsulation Sensitive Application Application Layer Layer 35555 80 Transport Transport Layer Data Layer Encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 At the Transport layer, the destination port address is checked. If the destination port address is port 80, the TCP header is removed, the data is send upwards to the web server in the Application layer. The web server will reply and the process will be reversed. Slide 30 Last update: Dec 10, 2024  Official (Closed) - Non Concept of Encapsulation and De-encapsulation Sensitive Application Application Layer Layer 35555 Transport Transport Layer Data Layer Encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 Slide 31 Last update: Dec 10, 2024  Official (Closed) - Non Concept of Encapsulation and De-encapsulation Sensitive Application Application Layer Layer 35555 80 Transport Transport Layer Layer Data De-encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 Slide 32 Last update: Dec 10, 2024  Official (Closed) - Non Concept of Encapsulation and De-encapsulation Sensitive Application Application Layer Layer 80 Transport Transport Layer Data Layer Encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 34-17-EB-B6-17-28 Slide 33 Last update: Dec 10, 2024  Official (Closed) - Non Concept of Encapsulation and De-encapsulation Sensitive Application Application Layer Layer 35555 80 Transport Transport Layer Layer Data De-encapsulation Internet Internet Layer Layer Network Interface Network Interface Layer Layer 153.20.57.151 153.20.57.125 34-17-EB-B6-10-F6 Slide 34 Last update: Dec 10, 2024  Official (Closed) - Non Concept of Encapsulation and De-encapsulation Sensitive Slide 35 Last update: Dec 10, 2024  Official (Closed) - Non Concept of Encapsulation and De-encapsulation Sensitive Source: https://www.elprocus.com/tcp-ip-protocol-architecture-and-its-layers/ Slide 36 Last update: Dec 10, 2024  Official (Closed) - Non Sensitive TCP/IP Developed by DARPA (US), this Protocol Suite is a hierarchical set of related protocols based on the Client- Server model which is adopted by the Internet. It is named from the first two of the most important protocols: Transmission Control Protocol (TCP) Internet Protocol (IP) Slide 37 Last update: Dec 10, 2024  Official (Closed) - Non 5-Layer TCP/IP Model Sensitive Application Application Original Transport Transport Later TCP/IP TCP/IP 4-Layer Internet Internet 5-Layer Model Model Data Network Link Data Link Interface Physical Physical Note:  The original TCP/IP model has only 4 layers. Subsequently the original Network Interface Layer was divided into Data Link (Layer 2) and Physical Layer (Layer 1). Slide 38 Last update: Dec 10, 2024  Official (Closed) - Non TCPIP Protocol Suite Sensitive A Protocol Suite is a hierarchical set of related protocols based on a reference model. TCP/IP (frequently used to refer to the whole protocol suite) is the most commonly used for communications across LANs and WANs. The main protocols (TCP, IP and Network Interface) checked for integrity of the data before accepting the data. Before eCommerce started to take off in the 90s, most data communications between any two devices are in plain text. Secure Socket Layer (SSL)/Transport Layer Security (TLS) protocol is used to encrypt communications between a web server and a browser. Slide 39 Last update: Dec 10, 2024  Official (Closed) - Non 5-Layer TCP/IP – Function of each layer Sensitive slide40 Slide 40 Last update: Dec 10, 2024  Official (Closed) - Non 5-Layer TCP/IP - Some Common Protocols/Services Sensitive Protocol Layer HTTP, DHCP, DNS, FTP etc. Application SSL/TLS TCP(more reliable), UDP(LESS Transport RELIABLE) IP Internet ARP Ethernet, Wireless LAN Network Interface - Data Link - Physical Transmission Medium (e.g. UTP, Optical Fibre, Wireless) Slide 41 Last update: Dec 10, 2024  Official (Closed) - Non Port Numbers (Recap) Sensitive  A port number uniquely identifies a network application process on a computer.  For example, in an incoming message/packet, the IP address is used to identify the destination computer, whereas the port number further specifies the destination application process in that computer. Some examples of well known ports:  HTTP port number is 80  FTP port number is 21  Secure Shell port number is 22  Telnet port number is 23  DNS port number is 53  HTTPS port number is 443 Slide 42 Last update: Dec 10, 2024  Official (Closed) - Non Activity 2: TCP/IP Protocol stack Sensitive Complete the following table to show the protocols involved at the different TCP/IP Protocol layer for the following services. Protocol Layer Assign IP Transfer Files over Web browsing Resolve domain name Addresses to a LAN using Wi-Fi of computer to IP computers address over a LAN automatically over a LAN Application DHCP FTP HTTP DNS Transport UDP TCP UDP UDP Internet IP IP IP IP Network Interface Slide 43 Last update: Dec 10, 2024  Official (Closed) - Non Activity 3: MAC & IP Address Sensitive  State whether it is a logical address or physical address for the following:  MAC address – Physical address >> Fixed, cannot change  IP address – logical address >> can be changed/ configure  Port number – logical address >> can be changed/ configured  Explain the two logical addresses needed for communications in a TCP/IP network. IP is to use from computer to computer TCP wat application process is used  State the Protocol Data Unit (PDU) associated with each of the following layer:  Application - message  Transport e.g. TCP - Segment  Internet - packet  Data Link e.g. MAC - frame  Physical e.g. PHY - bit Slide 44 Last update: Dec 10, 2024  Official (Closed) - Non Sensitive ~ The End ~ Slide 45 Last update: Dec 10, 2024