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COMP2004 Computer Networking & COMP2005 Computer Networking (Advanced) Spring 2024 Welcome, Administration & Module 1 1) Teaching staff contact details 5) vUWS 2) Learning guide 6) Cisco Networking Ac...

COMP2004 Computer Networking & COMP2005 Computer Networking (Advanced) Spring 2024 Welcome, Administration & Module 1 1) Teaching staff contact details 5) vUWS 2) Learning guide 6) Cisco Networking Academy 3) Assessment Summary 7) Module 1 Slides – Networking Today 4) Schedule of teaching and learning activities 8) Module 1 – Discussion Questions Teaching Staff Contact Details Subject Coordinator, Lecturer & Tutor Dr Nabil Giweli, Email: [email protected] Deputy Subject Coordinator, Lecturer & Tutor Ms Sharon Griffith, Email: [email protected] Tutors for lab workshops: Dr Raed Alsurdeh (Parramatta), Email: [email protected] Ms Maria Mikhail (Parramatta), Email: [email protected] Mr Mousa Abu Kashef (Parramatta), Email: [email protected] Ms Sarah Jones (Campbelltown and Kingswood), Email: [email protected] COMP2004 Subject Outline COMP2005 Subject Outline  Assessment Summary To pass this subject, you must: Attempt all assessment items AND attain a total subject mark of 50 or greater. Students not meeting this minimum mark may have demonstrated good practical skills but would not have demonstrated the required conceptual and theoretical understanding required of someone studying at a university level. In other words, to pass this subject you need to achieve 50% of the overall mark regardless of your achieved marks for each assessment (no threshold per assessment). However, not attending all practical sessions or one of the subject exams (i.e., Practical exam, Intra-term Exam or Final Exam) will result in failing the subject even if you have achieved the 50% overall mark or more (in this case, your grade will be Fail Non Submission, FNS). Learning Outcomes 1. Examine the fundamental concepts and protocols for computer networking and internetworking 2. Investigate and analyse the Internet architecture 3. Analyse the significance of the OSI and TCP/IP models, protocol stacks and their operation in computer networks 4. Evaluate modern technologies in computer networking 5. Investigate the functions of important OSI layer 2 and OSI layer 3 networking devices 6. Assess the management practices and security requirements of computer networks 7. Construct, test and troubleshoot a LAN design with introduced connectivity errors 8. Subnet an enterprise network given design criteria Schedule of teaching and learning activities 1 Schedule of teaching and learning activities 2 Learning Resources Information vUWS https://vuws.westernsydney.edu.au You will require a current WSU student account. Cisco Networking Academy (NetAcad) website for online course material & Cisco’s assessment server for module quizzes and final online quiz and much, much more. https://www.netacad.com You require a Cisco Networking Academy user account. Module 1: Networking Today Module Objectives Module Title: Networking Today Module Objective: Explain the advances in modern technologies. Topic Title Topic Objective Networks Affect our Lives Explain how networks affect our daily lives. Network Components Explain how host and network devices are used. Network Representations and Topologies Explain network representations and how they are used in network topologies. Common Types of Networks Compare the characteristics of common types of networks. Internet Connections Explain how LANs and WANs interconnect to the internet. Reliable Networks Describe the four basic requirements of a reliable network. Network Trends Explain how trends such as BYOD, online collaboration, video, and cloud computing are changing the way we interact. Network Security Identify some basic security threats and solution for all networks. The IT Professional Explain employment opportunities in the networking field. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 1.1 Networks Affect Our Lives © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12 Networking Today Networks Connect Us Communication is almost as important to us as our reliance on air, water, food, and shelter. In today’s world, through the use of networks, we are connected like never before. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 Networking Today No Boundaries World without boundaries Global communities Human network © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 1.2 Network Components © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 Network Components Host Roles Every computer on a network is called a host or end device. Servers are computers that provide information to end devices: email servers web servers Server Description Type file server Email Email server runs email server software. Clients are computers that send Clients use client software to access email. requests to the servers to retrieve Web Web server runs web server software. information: Clients use browser software to access web pages. web page from a web server email from an email server File File server stores corporate and user files. The client devices access these files. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16 Network Components Peer-to-Peer It is possible to have a device be a client and a server in a Peer-to-Peer Network. This type of network design is only recommended for very small networks. Advantages Disadvantages Easy to set up No centralized administration Less complex Not as secure Lower cost Not scalable Used for simple tasks: transferring files and sharing Slower performance printers © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 17 Network Components End Devices An end device is where a message originates from or where it is received. Data originates with an end device, flows through the network, and arrives at an end device. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18 Network Components Intermediary Network Devices An intermediary device interconnects end devices. Examples include switches, wireless access points, routers, and firewalls. Management of data as it flows through a network is also the role of an intermediary device, including: Regenerate and retransmit data signals. Maintain information about what pathways exist in the network. Notify other devices of errors and communication failures. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19 Network Components Network Media Communication across a network is carried through a medium which allows a message to travel from source to destination. Media Types Description Metal wires within cables Uses electrical impulses Glass or plastic fibers Uses pulses of light. within cables (fiber-optic cable) Wireless transmission Uses modulation of specific frequencies of electromagnetic waves. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 20 1.3 Network Representations and Topologies © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21 Network Representations and Topologies Network Representations Network diagrams, often called topology diagrams, use symbols to represent devices within the network. Important terms to know include: Network Interface Card (NIC) Physical Port Interface Note: Often, the terms port and interface are used interchangeably © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22 Network Representations and Topologies Topology Diagrams Physical topology diagrams illustrate the Logical topology diagrams illustrate devices, physical location of intermediary devices ports, and the addressing scheme of the and cable installation. network. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 23 1.4 Common Types of Networks © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 24 Common Types of Networks Networks of Many Sizes Small Home Networks – connect a few computers to each other and the Internet Small Office/Home Office – enables computer within a home or remote office to connect to a corporate network Small Home SOHO Medium to Large Networks – many locations with hundreds or thousands of interconnected computers World Wide Networks – connects hundreds of millions of computers world- wide – such as the internet Medium/Large World Wide © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 25 Common Types of Networks LANs and WANs Network infrastructures vary greatly in terms of: Size of the area covered Number of users connected Number and types of services available Area of responsibility Two most common types of networks: Local Area Network (LAN) Wide Area Network (WAN). © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 26 Common Types of Networks LANs and WANs (cont.) A LAN is a network infrastructure that spans A WAN is a network infrastructure that spans a small geographical area. a wide geographical area. LAN WAN Interconnect end devices in a limited area. Interconnect LANs over wide geographical areas. Administered by a single organization or Typically administered by one or more service individual. providers. Provide high-speed bandwidth to internal Typically provide slower speed links between LANs. devices. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 27 Common Types of Networks The Internet The internet is a worldwide collection of interconnected LANs and WANs. LANs are connected to each other using WANs. WANs may use copper wires, fiber optic cables, and wireless transmissions. The internet is not owned by any individual or group. The following groups were developed to help maintain structure on the internet: IETF ICANN IAB © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 28 Common Types of Networks Intranets and Extranets An intranet is a private collection of LANs and WANs internal to an organization that is meant to be accessible only to the organizations members or others with authorization. An organization might use an extranet to provide secure access to their network for individuals who work for a different organization that need access to their data on their network. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 29 1.5 Internet Connections © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 30 Internet Connections Internet Access Technologies There are many ways to connect users and organizations to the internet: Popular services for home users and small offices include broadband cable, broadband digital subscriber line (DSL), wireless WANs, and mobile services. Organizations need faster connections to support IP phones, video conferencing and data center storage. Business-class interconnections are usually provided by service providers (SP) and may include: business DSL, leased lines, and Metro Ethernet. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 31 Internet Connections Home and Small Office Internet Connections Connection Description Cable high bandwidth, always on, internet offered by cable television service providers. DSL high bandwidth, always on, internet connection that runs over a telephone line. Cellular uses a cell phone network to connect to the internet. Satellite major benefit to rural areas without Internet Service Providers. Dial-up an inexpensive, low bandwidth telephone option using a modem. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 32 Internet Connections Businesses Internet Connections Corporate business connections may Type of Description require: Connection Dedicated These are reserved circuits within higher bandwidth Leased Line the service provider’s network that dedicated connections connect distant offices with private voice and/or data networking. managed services Ethernet This extends LAN access technology WAN into the WAN. DSL Business DSL is available in various formats including Symmetric Digital Subscriber Lines (SDSL). Satellite This can provide a connection when a wired solution is not available. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 33 Internet Connections The Converging Network Before converged networks, an organization would have been separately cabled for telephone, video, and data. Each of these networks would use different technologies to carry the signal. Each of these technologies would use a different set of rules and standards. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 34 Internet Connections The Converging Network (Cont.) Converged data networks carry multiple services on one link including: data voice video Converged networks can deliver data, voice, and video over the same network infrastructure. The network infrastructure uses the same set of rules and standards. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 35 1.6 Reliable Networks © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 36 Reliable Network Network Architecture Network Architecture refers to the technologies that support the infrastructure that moves data across the network. There are four basic characteristics that the underlying architectures need to address to meet user expectations: Fault Tolerance Scalability Quality of Service (QoS) Security © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 37 Reliable Network Fault Tolerance A fault tolerant network limits the impact of a failure by limiting the number of affected devices. Multiple paths are required for fault tolerance. Reliable networks provide redundancy by implementing a packet switched network: Packet switching splits traffic into packets that are routed over a network. Each packet could theoretically take a different path to the destination. This is not possible with circuit-switched networks which establish dedicated circuits. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 38 Reliable Network Scalability A scalable network can expand quickly and easily to support new users and applications without impacting the performance of services to existing users. Network designers follow accepted standards and protocols in order to make the networks scalable. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 39 Reliable Network Quality of Service Voice and live video transmissions require higher expectations for those services being delivered. Have you ever watched a live video with constant breaks and pauses? This is caused when there is a higher demand for bandwidth than available – and QoS isn’t configured. Quality of Service (QoS) is the primary mechanism used to ensure reliable delivery of content for all users. With a QoS policy in place, the router can more easily manage the flow of data and voice traffic. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 40 Reliable Network There are two main types of network Network Security security that must be addressed: Network infrastructure security Physical security of network devices Preventing unauthorized access to the devices Information Security Protection of the information or data transmitted over the network Three goals of network security: Confidentiality – only intended recipients can read the data Integrity – assurance that the data has not be altered with during transmission Availability – assurance of timely and reliable access to data for authorized users © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 41 1.7 Network Trends © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 42 Network Trends Recent Trends The role of the network must adjust and continually transform in order to be able to keep up with new technologies and end user devices as they constantly come to the market. Several new networking trends that effect organizations and consumers: Bring Your Own Device (BYOD) Online collaboration Video communications Cloud computing © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 43 Network Trends Bring Your Own Device (BYOD) Bring Your Own Device allows users to use their own devices giving them more opportunities and greater flexibility. BYOD allows end users to have the freedom to use personal tools to access information and communicate using their: Laptops Netbooks Tablets Smartphones E-readers BYOD means any device, with any ownership, used anywhere. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 44 Network Trends Online Collaboration ▪ Collaborate and work with others over the network on joint projects. ▪ Collaboration tools including Cisco WebEx (shown in the figure) gives users a way to instantly connect and interact. ▪ Collaboration is a very high priority for businesses and in education. ▪ Cisco Webex Teams is a multifunctional collaboration tool. send instant messages post images post videos and links © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 45 Network Trends Video Communication Video calls are made to anyone, regardless of where they are located. Video conferencing is a powerful tool for communicating with others. Video is becoming a critical requirement for effective collaboration. Cisco TelePresence powers is one way of working where everyone, everywhere. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 46 Network Trends Cloud Computing Cloud computing allows us to store personal files or backup our data on servers over the internet. Applications can also be accessed using the Cloud. Allows businesses to deliver to any device anywhere in the world. Cloud computing is made possible by data centers. Smaller companies that can’t afford their own data centers, lease server and storage services from larger data center organizations in the Cloud. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 47 Network Trends Cloud Computing (Cont.) Four types of Clouds: Public Clouds Available to the general public through a pay-per-use model or for free. Private Clouds Intended for a specific organization or entity such as the government. Hybrid Clouds Made up of two or more Cloud types – for example, part custom and part public. Each part remains a distinctive object but both are connected using the same architecture. Community/Custom Clouds Built to meet the needs of a specific industry, such as healthcare or media. Can be private or public. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 48 Network Trends Technology Trends in the Home Smart home technology is a growing trend that allows technology to be integrated into every-day appliances which allows them to interconnect with other devices. Ovens might know what time to cook a meal for you by communicating with your calendar on what time you are scheduled to be home. Smart home technology is currently being developed for all rooms within a house. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 49 Network Trends Powerline networking can Powerline Networking allow devices to connect to a LAN where data network cables or wireless communications are not a viable option. Using a standard powerline adapter, devices can connect to the LAN wherever there is an electrical outlet by sending data on certain frequencies. Powerline networking is especially useful when wireless access points cannot reach all the devices in the home. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 50 Network Trends Wireless Broadband In addition to DSL and cable, wireless is another option used to connect homes and small businesses to the internet. More commonly found in rural environments, a Wireless Internet Service Provider (WISP) is an ISP that connects subscribers to designated access points or hotspots. Wireless broadband is another solution for the home and small businesses. Uses the same cellular technology used by a smart phone. An antenna is installed outside the house providing wireless or wired connectivity for devices in the home. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 51 1.8 Network Security © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 52 Network Security Security Threats Network security is an integral part of networking regardless of the size of the network. The network security that is implemented must take into account the environment while securing the data, but still allowing for quality of service that is expected of the network. Securing a network involves many protocols, technologies, devices, tools, and techniques in order to secure data and mitigate threats. Threat vectors might be external or internal. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 53 Network Security External Threats: Security Threats (Cont.) Viruses, worms, and Trojan horses Spyware and adware Zero-day attacks Threat Actor attacks Denial of service attacks Data interception and theft Identity theft Internal Threats: lost or stolen devices accidental misuse by employees malicious employees © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 54 Network Security Security Solutions Security must be implemented in multiple layers using more than one security solution. Network security components for home or small office network: Antivirus and antispyware software should be installed on end devices. Firewall filtering used to block unauthorized access to the network. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 55 Network Security Security Solutions (Cont.) Larger networks have additional security requirements: Dedicated firewall system Access control lists (ACL) Intrusion prevention systems (IPS) Virtual private networks (VPN) The study of network security starts with a clear understanding of the underlying switching and routing infrastructure. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 56 1.9 The IT Professional © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 57 The IT Professional The Cisco Certified Network Associate CCNA (CCNA) certification: demonstrates that you have a knowledge of foundational technologies ensures you stay relevant with skills needed for the adoption of next-generation technologies. The new CCNA focus: IP foundation and security topics Wireless, virtualization, automation, and network programmability. New DevNet certifications at the associate, specialist and professional levels, to validate your software development skills. Specialist certification validate your skills in line with your job role and interests. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 58 The IT Professional Networking Jobs At www.netacad.com you can click the Careers menu and then select Employment opportunities. Find employment opportunities by using the Talent Bridge Matching Engine. Search for jobs with Cisco, Cisco partners and distributors seeking Cisco Networking Academy students and alumni. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 59 Module Practice and Quiz What did I learn in this module? Through the use of networks, we are connected like never before. All computers that are connected to a network and participate directly in network communication are classified as hosts. Diagrams of networks often use symbols to represent the different devices and connections that make up a network. A diagram provides an easy way to understand how devices connect in a large network. The two types of network infrastructures are Local Area Networks (LANs), and Wide Area Networks (WANs). SOHO internet connections include cable, DSL, Cellular, Satellite, and Dial-up telephone. Business internet connections include Dedicated Leased Line, Metro Ethernet, Business DSL, and Satellite. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 60 Module Practice and Quiz What did I learn in this module? (Cont.) Network architecture refers to the technologies that support the infrastructure and the programmed services and rules, or protocols, that move data across the network. There are four basic characteristics of network architecture: Fault Tolerance, Scalability, Quality of Service (QoS), and Security. Recent networking trends that affect organizations and consumers: Bring Your Own Device (BYOD), online collaboration, video communications, and cloud computing. There are several common external and internal threats to networks. Larger networks and corporate networks use antivirus, antispyware, and firewall filtering, but they also have other security requirements: Dedicated firewall systems, Access control lists (ACL), Intrusion prevention systems (IPS), and Virtual private networks (VPN) The Cisco Certified Network Associate (CCNA) certification demonstrates your knowledge of foundational technologies. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 61 Module 1 New Terms and Commands Peer-to-Peer File Sharing Logical topology diagram Network bandwidth Small Office/Home Office or Local Area Network (LAN) Bring Your Own Device (BYOD) SOHO Wide Area Network (WAN) Collaboration Medium to large network Internet Cloud computing Server Intranet Private clouds Client Extranet Hybrid clouds Peer-to-Peer network Internet Service Provider (ISP) Public clouds End device Converged networks Custom clouds Intermediary device Network architecture Data center Medium Fault tolerant network Smart home technology Network Interface Card (NIC) Packet-switched network Powerline networking Physical Port Circuit-switched network Wireless Internet Service Interface Scalable network Provider (WISP) Physical topology diagram Quality of Service (Qos) Network architecture © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 62 Module 1: Discussion Questions Topic 1.1 How does the Internet create global communities? What are the trending Internet technologies available now? Topic 1.2 What do you think of when someone uses the term “host”. What is a “host”? What is the difference between a server client network verses a peer-to-peer (P2P) network? What challenges can we have with P2P networks? Topic 1.3 Create a Packet Tracer showing a basic topology with some key devices (switch/router)and how they connect to a PC/server/laptop. What are the differences between the physical and logical topologies? © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 63 Module 1: Discussion Questions (Cont.) Topic 1.4 What kind of equipment do you have on your home network? Consider that all of these items are on the larger networks. The difference is in ability, quantity, and cost of a companies equipment. Topic 1.5 How do you connect to the Internet at home? Does anyone ever remember connecting via dialup modem? Do you use a VoIP phone service bundled from your ISP. This is an example of a home converged network. Topic 1.6 What is QoS? How can Confidentiality, Integrity, and Availability be implemented in networks? © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 64 Module 1: Discussion Questions (Cont.) Topic 1.7 What devices do you BYOD to and where? What is Cloud Computing and do you use it? If so, what for? What is a Custom Cloud? How could we use smart home technology? Topic1.8 What kind of internal threats might a network administrator see in an organization? Why are internal attacks as important to address as external attacks? © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 65 © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 66 COMP2004 Computer Networking & COMP2005 Computer Networking (Advanced) Spring 2024 Basic Switch and End Device Configuration Module 2 © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1 Module Objectives Module Title: Basic Switch and End Device Configuration Module Objective: Implement initial settings including passwords, IP addressing, and default gateway parameters on a network switch and end devices. Topic Title Topic Objective Explain how to access a Cisco IOS device for configuration Cisco IOS Access purposes. Explain how to navigate Cisco IOS to configure network IOS Navigation devices. The Command Structure Describe the command structure of Cisco IOS software. Basic Device Configuration Configure a Cisco IOS device using CLI. Save Configurations Use IOS commands to save the running configuration. Ports and Addresses Explain how devices communicate across network media. Configure IP Addressing Configure a host device with an IP address. Verify Connectivity Verify connectivity between two end devices. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 2.1 Cisco IOS Access © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3 Cisco IOS Access Operating Systems Shell - The user interface that allows users to request specific tasks from the computer. These requests can be made either through the CLI or GUI interfaces. Kernel - Communicates between the hardware and software of a computer and manages how hardware resources are used to meet software requirements. Hardware - The physical part of a computer including underlying electronics. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4 Cisco IOS Access GUI A GUI allows the user to interact with the system using an environment of graphical icons, menus, and windows. A GUI is more user-friendly and requires less knowledge of the underlying command structure that controls the system. Examples of these are: Windows, macOS, Linux KDE, Apple iOS and Android. GUIs can fail, crash, or simply not operate as specified. For these reasons, network devices are typically accessed through a CLI. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5 Cisco IOS Access Purpose of an OS PC operating system enables a user to do CLI-based network operating system enables a the following: network technician to do the following: Use a mouse to make selections Use a keyboard to run CLI-based and run programs network programs Enter text and text-based Use a keyboard to enter text and commands text-based commands View output on a monitor View output on a monitor © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 6 Cisco IOS Access Access Methods Console – A physical management port used to access a device in order to provide maintenance, such as performing the initial configurations. Secure Shell (SSH) – Establishes a secure remote CLI connection to a device, through a virtual interface, over a network. (Note: This is the recommended method for remotely connecting to a device.) Telnet – Establishes an insecure remote CLI connection to a device over the network. (Note: User authentication, passwords and commands are sent over the network in plaintext.) © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 7 Cisco IOS Access Terminal Emulation Programs Terminal emulation programs are used to connect to a network device by either a console port or by an SSH/Telnet connection. There are several terminal emulation programs to chose from such as PuTTY, Tera Term and SecureCRT. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 8 2.2 IOS Navigation © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9 IOS Navigation Primary Command Modes User EXEC Mode: Allows access to only a limited number of basic monitoring commands Identified by the CLI prompt that ends with the > symbol Privileged EXEC Mode: Allows access to all commands and features Identified by the CLI prompt that ends with the # symbol © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10 IOS Navigation Configuration Mode and Subconfiguration Modes Global Configuration Mode: Used to access configuration options on the device Line Configuration Mode: Used to configure console, SSH, Telnet or AUX access Interface Configuration Mode: Used to configure a switch port or router interface © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 IOS Navigation Video – IOS CLI Primary Command Modes This video will cover the following: User EXEC mode Privilege EXEC mode Global Config mode See 2.2.3 in the NetAcad course. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12 IOS Navigation Navigation Between IOS Modes ▪ Privileged EXEC Mode: To move from user EXEC mode to privilege EXEC mode, use the enabled command. ▪ Global Configuration Mode: To move in and out of global configuration mode, use the configure terminal command. To return to privilege EXEC mode, use the exit command. ▪ Line Configuration Mode: To move in and out of line configuration mode, use the line command followed by the management line type. To return to global configuration mode, use the exit command. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 IOS Navigation Navigation Between IOS Modes (Cont.) Subconfiguration Modes: To move out of any subconfiguration mode to get back to global configuration mode, use the exit command. To return to privilege EXEC mode, use the end command or key combination Ctrl +Z. To move directly from one subconfiguration mode to another, type in the desired subconfiguration mode command. In the example, the command prompt changes from (config-line)# to (config-if)#. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 IOS Navigation Video – Navigation Between IOS Modes This video will cover the following: enable disable configure terminal exit end Control + Z on keyboard Other commands to enter sub configuration modes © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 2.3 The Command Structure © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16 The Command Structure Basic IOS Command Structure Keyword – This is a specific parameter defined in the operating system (in the figure, ip protocols). Argument - This is not predefined; it is a value or variable defined by the user (in the figure, 192.168.10.5). © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 17 The Command Structure IOS Command Syntax Check A command might require one or more arguments. To determine the keywords and arguments required for a command, refer to the command syntax. Boldface text indicates commands and keywords that are entered as shown. Italic text indicates an argument for which the user provides the value. Convention Description Boldface text indicates commands and keywords that you enter literally as boldface shown. italics Italic text indicates arguments for which you supply values. [x] Square brackets indicate an optional element (keyword or argument). {x} Braces indicate a required element (keyword or argument). Braces and vertical lines within square brackets indicate a required choice [x {y | z }] within an optional element. Spaces are used to clearly delineate parts of the command. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18 The Command Structure IOS Command Syntax Check (Cont.) ▪ The command syntax provides the pattern, or format, that must be used when entering a command. ▪ The command is ping and the user-defined argument is the ip-address of the destination device. For example, ping 10.10.10.5. ▪ The command is traceroute and the user-defined argument is the ip- address of the destination device. For example, traceroute 192.168.254.254. ▪ If a command is complex with multiple arguments, you may see it represented like this: © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19 The Command Structure IOS Help Features The IOS has two forms of help available: context-sensitive help and command syntax check. Context-sensitive help enables you to Command syntax check verifies that quickly find answers to these questions: a valid command was entered by Which commands are available in each command the user. mode? If the interpreter cannot understand the Which commands start with specific characters or command being entered, it will provide group of characters? feedback describing what is wrong with the command. Which arguments and keywords are available to particular commands? © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 20 The Command Structure Video – Context Sensitive Help and Command Syntax Checker This video will cover the following: Use the help command in user EXEC, privileged EXEC, and global config mode Finish commands and arguments with the help command Use the command syntax checker to fix syntax errors and incomplete commands See section 2.3.4. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21 The Command Structure Hot Keys and Shortcuts The IOS CLI provides hot keys and shortcuts that make configuring, monitoring, and troubleshooting easier. Commands and keywords can be shortened to the minimum number of characters that identify a unique selection. For example, the configure command can be shortened to conf because configure is the only command that begins with conf. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22 The Command Structure Hot Keys and Shortcuts (Cont.) ▪ The table below is a brief list of keystrokes to enhance command line editing. Keystroke Description Tab Completes a partial command name entry. Backspace Erases the character to the left of the cursor. Left Arrow or Ctrl+B Moves the cursor one character to the left. Right Arrow or Ctrl+F Moves the cursor one character to the right. Recalls the commands in the history buffer, beginning with Up Arrow or Ctrl+P the most recent commands. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 23 The Command Structure Hot Keys and Shortcuts (Cont.) When a command output produces more text than can be displayed in a terminal window, The table below lists commands that can the IOS will display a “--More--” prompt. The be used to exit out of an operation. table below describes the keystrokes that can be used when this prompt is displayed. Keystroke Description Keystroke Description When in any configuration mode, ends the Enter Key Displays the next line. Ctrl-C configuration mode and returns to privileged EXEC mode. When in any configuration mode, ends the Space Bar Displays the next screen. Ctrl-Z configuration mode and returns to privileged EXEC mode. Ends the display string, returning to All-purpose break sequence used to abort DNS Any other key Ctrl-Shift-6 privileged EXEC mode. lookups, traceroutes, pings, etc. Note: To see more hot keys and shortcuts refer to 2.3.5. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 24 The Command Structure Video – Hot Keys and Shortcuts This video will cover the following: Tab key (tab completion) Command shortening Up and down arrow key CTRL + C CTRL + Z CTRL + Shift + 6 CTRL + R © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 25 2.4 Basic Device Configuration © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 26 Basic Device Configuration Device Names The first configuration command on any device should be to give it a unique hostname. By default, all devices are assigned a factory default name. For example, a Cisco IOS switch is "Switch.” Guideline for naming devices: Start with a letter Contain no spaces End with a letter or digit Note: To return the switch to the default Use only letters, digits, and dashes prompt, use the no hostname global Be less than 64 characters in length config command. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 27 Basic Device Configuration Password Guidelines The use of weak or easily guessed passwords are a security concern. All networking devices should limit administrative access by securing privileged EXEC, user EXEC, and remote Telnet access with passwords. In addition, all passwords should be encrypted and legal notifications provided. Password Guidelines: Use passwords that are more than eight characters in length. Use a combination of upper and lowercase letters, numbers, special characters, and/or numeric sequences. Note: Most of the labs in this course use simple passwords such as cisco or class. These passwords Avoid using the same password for all devices. are considered weak and easily guessable and should Do not use common words because they are be avoided in production environments. easily guessed. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 28 Basic Device Configuration Configure Passwords Securing user EXEC mode access: First enter line console configuration mode using the line console 0 command in global configuration mode. Next, specify the user EXEC mode password using the password password command. Finally, enable user EXEC access using the login command. Securing privileged EXEC mode access: First enter global configuration mode. Next, use the enable secret password command. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 29 Basic Device Configuration Configure Passwords (Cont.) Securing VTY line access: First enter line VTY configuration mode using the line vty 0 15 command in global configuration mode. Next, specify the VTY password using the password password command. Finally, enable VTY access using the login command. ▪ Note: VTY lines enable remote access using Telnet or SSH to the device. Many Cisco switches support up to 16 VTY lines that are numbered 0 to 15. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 30 Basic Device Configuration Encrypt Passwords ▪ The startup-config and running-config files ▪ Use the show running-config command display most passwords in plaintext. to verify that the passwords on the device are now encrypted. ▪ To encrypt all plaintext passwords, use the service password-encryption global config command. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 31 Basic Device Configuration Banner Messages ▪ A banner message is important to warn unauthorized personnel from attempting to access the device. ▪ To create a banner message of the day on a network device, use the banner The banner will be displayed on attempts to access the device. motd # the message of the day # global config command. Note: The “#” in the command syntax is called the delimiting character. It is entered before and after the message. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 32 Basic Device Configuration Video – Secure Administrative Access to a Switch This video will cover the following: Access the command line to secure the switch Secure access to the console port Secure virtual terminal access for remote access Encrypt passwords on the switch Configure the banner message Verify security changes See 2.4.6 section. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 33 2.5 Save Configurations © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 34 Save Configurations Configuration Files ▪ There are two system files that store the device configuration: startup-config - This is the saved configuration file that is stored in NVRAM. It contains all the commands that will be used by the device upon startup or reboot. Flash does not lose its contents when the device is powered off. running-config - This is stored in Random Access Memory (RAM). It reflects the current configuration. Modifying a running configuration affects the operation of a Cisco device immediately. RAM is volatile memory. It loses all of its content when the device is powered off or restarted. To save changes made to the running configuration to the startup configuration file, use the copy running-config startup-config privileged EXEC mode command. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 35 Save Configurations Alter the Running Configurations If changes made to the running config do not have the desired effect and the running-config has not yet been saved, you can restore the device to its previous configuration. To do this you can: Remove the changed commands individually. Reload the device using the reload command in privilege EXEC mode. Note: This will cause the device to briefly go offline, leading to network downtime. If the undesired changes were saved to the startup-config, it may be necessary to clear all the configurations using the erase startup- config command in privilege EXEC mode. After erasing the startup-config, reload the device to clear the running-config file from RAM. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 36 Save Configurations Video – Alter the Running Configuration This video will cover the following: Copy the running-config file to the startup-config file Show the files in the flash or NVRAM directory Use command shortening Erase the startup-config file Copy the start-config file to the running-config file © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 37 Save Configurations Capture Configuration to a Text File Configuration files can also be saved and archived to a text document. Step 1. Open terminal emulation software, such as PuTTY or Tera Term, that is already connected to a switch. Step 2. Enable logging in to the terminal software and assign a name and file location to save the log file. The figure displays that All session output will be captured to the file specified (i.e., MySwitchLogs). © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 38 Save Configurations Capture Configuration to a Text File (Cont.) Step 3. Execute the show running- config or show startup-config command at the privileged EXEC prompt. Text displayed in the terminal window will be placed into the chosen file. Step 4. Disable logging in the terminal software. The figure shows how to disable logging by choosing the None session logging option Note: The text file created can be used as a record of how the device is currently implemented. The file could require editing before being used to restore a saved configuration to a device. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 39 2.6 Ports and Addresses © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 40 Ports and Addresses IP Addresses The use of IP addresses is the primary means of enabling devices to locate one another and establish end-to-end communication on the internet. The structure of an IPv4 address is called dotted decimal notation and is represented by four decimal numbers between 0 and 255. An IPv4 subnet mask is a 32-bit value that differentiates the network portion of the address from the host portion. Coupled with the IPv4 address, the subnet mask determines to which subnet the device is a member. The default gateway address is the IP address of the router that the host will use to access remote networks, including the internet. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 41 Ports and Addresses IP Addresses (Cont.) IPv6 addresses are 128 bits in length and written as a string of hexadecimal values. Every four bits is represented by a single hexadecimal digit; for a total of 32 hexadecimal values. Groups of four hexadecimal digits are separated by a colon “:”. IPv6 addresses are not case-sensitive and can be written in either lowercase or uppercase. Note: IP in this course refers to both the IPv4 and IPv6 protocols. IPv6 is the most recent version of IP and is replacing the more common IPv4. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 42 Ports and Addresses Interfaces and Ports Network communications depend on end user device interfaces, networking device interfaces, and the cables that connect them. Types of network media include twisted- pair copper cables, fiber-optic cables, coaxial cables, or wireless. Different types of network media have different features and benefits. Some of the differences between various types of media include: Distance the media can successfully carry a signal Environment in which the media is to be installed Amount of data and the speed at which it must be transmitted Cost of the media and installation © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 43 2.7 Configure IP Addressing © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 44 Configure IP Addressing Manual IP Address Configuration for End Devices End devices on the network need an IP address in order to communicate with other devices on the network. IPv4 address information can be entered into end devices manually, or automatically using Dynamic Host Configuration Protocol (DHCP). To manually configure an IPv4 address on a Windows PC, open the Control Panel > Network Sharing Center > Change adapter settings and choose the adapter. Next right-click and select Properties to display the Local Area Connection Properties. Next, click Properties to open the Internet Protocol Version 4 (TCP/IPv4) Properties window. Then configure the IPv4 address and subnet mask information, and default gateway. Note: IPv6 addressing and configuration options are similar to IPv4. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 45 Configure IP Addressing Automatic IP Address Configuration for End Devices DHCP enables automatic IPv4 address configuration for every end device that is DHCP-enabled. End devices are typically by default using DHCP for automatic IPv4 address configuration. To configure DHCP on a Windows PC, open the Control Panel > Network Sharing Center > Change adapter settings and choose the adapter. Next right-click and select Properties to display the Local Area Connection Properties. Next, click Properties to open the Internet Protocol Version 4 (TCP/IPv4) Properties window, then select Obtain an Note: IPv6 uses DHCPv6 and SLAAC (Stateless Address IP address automatically and Obtain DNS Autoconfiguration) for dynamic address allocation. server address automatically. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 46 Configure IP Addressing Switch Virtual Interface Configuration To access the switch remotely, an IP address and a subnet mask must be configured on the SVI. To configure an SVI on a switch: Enter the interface vlan 1 command in global configuration mode. Next assign an IPv4 address using the ip address ip-address subnet-mask command. Finally, enable the virtual interface using the no shutdown command. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 47 2.8 Verify Connectivity © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 48 Verify Connectivity Video – Test the Interface Assignment This video will cover the following: ▪ Connect a console cable from the PC to the switch ▪ Use the terminal emulation program and accept the defaults to bring you to the command line ▪ Use enable to enter privileged EXEC mode ▪ Use the global configuration mode and the interface configuration mode to enter the no shutdown command © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 49 Verify Connectivity Video – Test End-to-End Connectivity This video will cover the use of the ping command to test connectivity on both switches and both PCs. See 2.8.1 in the NetAcad course. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 50 Module Practice and Quiz What did I learn in this module? All end devices and network devices require an operating system (OS). Cisco IOS software separates management access into the following two command modes: User EXEC Mode and Privileged EXEC Mode. Global configuration mode is accessed before other specific configuration modes. From global config mode, the user can enter different subconfiguration modes. Each IOS command has a specific format or syntax and can only be executed in the appropriate mode. Basic device configurations- hostname, password, encrypt passwords and banner. There are two system files that store the device configuration: startup- config and running-config. IP addresses enable devices to locate one another and establish end- to-end communication on the internet. Each end device on a network must be configured with an IP address. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 51 Module 2 : Basic Switch and End Device Configuration New Terms and Commands operating system (OS) line configuration mode console CLI interface configuration mode enable secret GUI Enable VTY line shell configure terminal show running-config kernel exit banner motd hardware end startup-config console argument running-config Secure Shell (SSH) keyword reload Telnet command syntax erase startup-config terminal emulation ping DHCP programs traceroute switch virtual interface (SVI) user EXEC mode help command ”?” ipconfig privileged EXEC mode hot keys show ip int brief hostname © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 52 Module 2: Discussion Questions Topic 2.1 What are the advantages and disadvantages of using a GUI interface or CLI? Why is SSH more important to use instead of Telnet? Topic 2.2 What are the differences between User EXEC mode and Privileged EXEC mode? Why are the commands available in User EXEC mode limited? What are the differences between Privilege EXEC mode and Global Configuration mode? Topic 2.3 What are some hot keys or shortcuts used for ISO CLI commands? © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 53 Module 2: Discussion Questions (Cont.) Topic 2.4 What are the guidelines for naming a network device and why the default name should be changed? Why would you want to encrypt all the passwords on a switch? Why is a banner important to configure on a network device? Topic 2.5 What would be a disadvantage of reloading a switch? What is the difference between the running-config and the startup-config? © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 54 Module 2: Discussion Questions (Cont.) Topic 2.6 Name some end devices that are configured with IP addresses. Why do they need to be configured with an IP address? Topic 2.7 Have you ever configured your computer with a manual IP address? Why do you need to use the no shutdown command on an interface? Topic 2.8 Why is it important to test end-to-end connectivity? © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 55 © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 56 COMP2004 Computer Networking & COMP2005 Computer Networking (Advanced) Spring 2024 Protocols and Models & Physical Layer Week 3 - Modules 3 & 4 © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1 COMP2004 Computer Networking & COMP2005 Computer Networking (Advanced) Spring 2024 Protocols and Models Module 3 © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 Module Objectives Module Title: Protocols and Models Module Objective: Explain how network protocols enable devices to access local and remote network resources. Topic Title Topic Objective The Rules Describe the types of rules that are necessary to successfully communicate. Protocols Explain why protocols are necessary in network communication. Protocol Suites Explain the purpose of adhering to a protocol suite. Standards Organizations Explain the role of standards organizations in establishing protocols for network interoperability. Reference Models Explain how the TCP/IP model and the OSI model are used to facilitate standardization in the communication process. Data Encapsulation Explain how data encapsulation allows data to be transported across the network. Data Access Explain how local hosts access local resources on a network. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 3 3.1 The Rules © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4 The Rules Video – Devices in a Bubble This video will explain the protocols that devices use to see their place in the network and communicate with other devices. See 3.1.1 in the NetAcad course. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5 The Rules Communications Fundamentals Networks can vary in size and complexity. It is not enough to have a connection, devices must agree on “how” to communicate. There are three elements to any communication: There will be a source (sender). There will be a destination (receiver). There will be a channel (media) that provides for the path of communications to occur. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 6 The Rules Communications Protocols All communications are governed by protocols. Protocols are the rules that communications will follow. These rules will vary depending on the protocol. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 7 The Rules Rule Establishment Individuals must use established rules or agreements to govern the conversation. The first message is difficult to read because it is not formatted properly. The second shows the message properly formatted © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 8 The Rules Rule Establishment (Cont.) Protocols must account for the following requirements: An identified sender and receiver Common language and grammar Speed and timing of delivery Confirmation or acknowledgment requirements © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9 The Rules Network Protocol Requirements Common computer protocols must be in agreement and include the following requirements: Message encoding Message formatting and encapsulation Message size Message timing Message delivery options © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10 The Rules Message Encoding Encoding is the process of converting information into another acceptable form for transmission. Decoding reverses this process to interpret the information. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 The Rules Message Formatting and Encapsulation When a message is sent, it must use a specific format or structure. Message formats depend on the type of message and the channel that is used to deliver the message. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12 The Rules Message Size Encoding between hosts must be in an appropriate format for the medium. Messages sent across the network are converted to bits The bits are encoded into a pattern of light, sound, or electrical impulses. The destination host must decode the signals to interpret the message. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 The Rules Message Timing Message timing includes the following: Flow Control – Manages the rate of data transmission and defines how much information can be sent and the speed at which it can be delivered. Response Timeout – Manages how long a device waits when it does not hear a reply from the destination. Access method - Determines when someone can send a message. There may be various rules governing issues like “collisions”. This is when more than one device sends traffic at the same time and the messages become corrupt. Some protocols are proactive and attempt to prevent collisions; other protocols are reactive and establish a recovery method after the collision occurs. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 The Rules Message Delivery Options Message delivery may one of the following methods: Unicast – one to one communication Multicast – one to many, typically not all Broadcast – one to all Note: Broadcasts are used in IPv4 networks, but are not an option for IPv6. Later we will also see “Anycast” as an additional delivery option for IPv6. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 The Rules A Note About the Node Icon Documents may use the node icon , typically a circle, to represent all devices. The figure illustrates the use of the node icon for delivery options. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16 3.2 Protocols © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 17 Protocols Network Protocol Overview Network protocols define a Protocol Type Description common set of rules. Can be implemented on devices in: Network enable two or more devices to communicate over Communications one or more networks Software Hardware Network Security secure data to provide authentication, data integrity, and data encryption Both Protocols have their own: Routing enable routers to exchange route information, compare path information, and select best path Function Format Service used for the automatic detection of devices or Rules Discovery services © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 18 Protocols Network Protocol Functions Devices use agreed-upon protocols to communicate. Protocols may have one or more functions. Function Description Addressing Identifies sender and receiver Reliability Provides guaranteed delivery Flow Control Ensures data flows at an efficient rate Sequencing Uniquely labels each transmitted segment of data Error Detection Determines if data became corrupted during transmission Application Interface Process-to-process communications between network applications © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 19 Protocols Protocol Interaction Networks require the use of several protocols. Each protocol has its own function and format. Protocol Function Hypertext Transfer ▪ Governs the way a web server and a web client interact Protocol (HTTP) ▪ Defines content and format Transmission Control ▪ Manages the individual conversations Protocol (TCP) ▪ Provides guaranteed delivery ▪ Manages flow control Internet Protocol (IP) Delivers messages globally from the sender to the receiver Ethernet Delivers messages from one NIC to another NIC on the same Ethernet Local Area Network (LAN) © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 20 3.3 Protocol Suites © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 21 Protocol Suites Network Protocol Suites Protocols must be able to work with other protocols. Protocol suite: A group of inter-related protocols necessary to perform a communication function Sets of rules that work together to help solve a problem The protocols are viewed in terms of layers: Higher Layers Lower Layers- concerned with moving data and provide services to upper layers © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 22 Protocol Suites Evolution of Protocol Suites There are several protocol suites. Internet Protocol Suite or TCP/IP- The most common protocol suite and maintained by the Internet Engineering Task Force (IETF) Open Systems Interconnection (OSI) protocols- Developed by the International Organization for Standardization (ISO) and the International Telecommunications Union (ITU) AppleTalk- Proprietary suite release by Apple Inc. Novell NetWare- Proprietary suite developed by Novell Inc. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 23 Protocol Suites TCP/IP Protocol Example TCP/IP protocols operate at the application, transport, and internet layers. The most common network access layer LAN protocols are Ethernet and WLAN (wireless LAN). © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 24 Protocol Suites TCP/IP Protocol Suite TCP/IP is the protocol suite used by the internet and includes many protocols. TCP/IP is: An open standard protocol suite that is freely available to the public and can be used by any vendor A standards-based protocol suite that is endorsed by the networking industry and approved by a standards organization to ensure interoperability © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 25 Protocol Suites TCP/IP Communication Process A web server encapsulating and sending a A client de-encapsulating the web page for web page to a client. the web browser © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 26 3.4 Standards Organizations © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 27 Standards Organizations Open Standards Open standards encourage: interoperability competition innovation Standards organizations are: vendor-neutral non-profit organizations established to develop and promote the concept of open standards. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 28 Standards Organizations Internet Society (ISOC) - Promotes Internet Standards the open development and evolution of internet Internet Architecture Board (IAB) - Responsible for management and development of internet standards Internet Engineering Task Force (IETF) - Develops, updates, and maintains internet and TCP/IP technologies Internet Research Task Force (IRTF) - Focused on long-term research related to internet and TCP/IP protocols © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 29 Standards Organizations Internet Standards (Cont.) Standards organizations involved with the development and support of TCP/IP Internet Corporation for Assigned Names and Numbers (ICANN) - Coordinates IP address allocation, the management of domain names, and assignment of other information Internet Assigned Numbers Authority (IANA) - Oversees and manages IP address allocation, domain name management, and protocol identifiers for ICANN © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 30 Standards Organizations Electronic and Communications Standards Institute of Electrical and Electronics Engineers (IEEE, pronounced “I-triple-E”) - dedicated to creating standards in power and energy, healthcare, telecommunications, and networking Electronic Industries Alliance (EIA) - develops standards relating to electrical wiring, connectors, and the 19-inch racks used to mount networking equipment Telecommunications Industry Association (TIA) - develops communication standards in radio equipment, cellular towers, Voice over IP (VoIP) devices, satellite communications, and more International Telecommunications Union-Telecommunication Standardization Sector (ITU-T) - defines standards for video compression, Internet Protocol Television (IPTV), and broadband communications, such as a digital subscriber line (DSL) © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 31 3.5 Reference Models © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 32 Reference Models The Benefits of Using a Layered Model Complex concepts such as how a network operates can be difficult to explain and understand. For this reason, a layered model is used. Two layered models describe network operations: Open System Interconnection (OSI) Reference Model TCP/IP Reference Model © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 33 Reference Models The Benefits of Using a Layered Model (Cont.) These are the benefits of using a layered model: Assist in protocol design because protocols that operate at a specific layer have defined information that they act upon and a defined interface to the layers above and below Foster competition because products from different vendors can work together Prevent technology or capability changes in one layer from affecting other layers above and below Provide a common language to describe networking functions and capabilities © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 34 Reference Models The OSI Reference Model OSI Model Layer Description 7 - Application Contains protocols used for process-to-process communications. Provides for common representation of the data transferred between application 6 - Presentation layer services. 5 - Session Provides services to the presentation layer and to manage data exchange. Defines services to segment, transfer, and reassemble the data for individual 4 - Transport communications. 3 - Network Provides services to exchange the individual pieces of data over the network. 2 - Data Link Describes methods for exchanging data frames over a common media. 1 - Physical Describes the means to activate, maintain, and de-activate physical connections. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 35 Reference Models The TCP/IP Reference Model TCP/IP Model Description Layer Application Represents data to the user, plus encoding and dialog control. Transport Supports communication between various devices across diverse networks. Internet Determines the best path through the network. Network Access Controls the hardware devices and media that make up the network. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 36 Reference Models OSI and TCP/IP Model Comparison The OSI model divides the network access layer and the application layer of the TCP/IP model into multiple layers. The TCP/IP protocol suite does not specify which protocols to use when transmitting over a physical medium. OSI Layers 1 and 2 discuss the necessary procedures to access the media and the physical means to send data over a network. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 37 3.6 Data Encapsulation © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 38 Data Encapsulation Segmenting Messages Segmenting is the process of breaking up messages into smaller units. Multiplexing is the processes of taking multiple streams of segmented data and interleaving them together. Segmenting messages has two primary benefits: Increases speed - Large amounts of data can be sent over the network without tying up a communications link. Increases efficiency - Only segments which fail to reach the destination need to be retransmitted, not the entire data stream. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 39 Data Encapsulation Sequencing Sequencing messages is the process of numbering the segments so that the message may be reassembled at the destination. TCP is responsible for sequencing the individual segments. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 40 Data Encapsulation Encapsulation is the process where protocols Protocol Data Units add their information to the data. At each stage of the process, a PDU has a different name to reflect its new functions. There is no universal naming convention for PDUs, in this course, the PDUs are named according to the protocols of the TCP/IP suite. PDUs passing down the stack are as follows: 1. Data (Data Stream) 2. Segment 3. Packet 4. Frame 5. Bits (Bit Stream) © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 41 Data Encapsulation Encapsulation Example Encapsulation is a top down process. The level above does its process and then passes it down to the next level of the model. This process is repeated by each layer until it is sent out as a bit stream. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 42 Data Encapsulation De-encapsulation Example Data is de-encapsulated as it moves up the stack. When a layer completes its process, that layer strips off its header and passes it up to the next level to be processed. This is repeated at each layer until it is a data stream that the application can process. 1. Received as Bits (Bit Stream) 2. Frame 3. Packet 4. Segment 5. Data (Data Stream) © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 43 3.7 Data Access © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 44 Data Access Addresses Both the data link and network layers use addressing to deliver data from source to destination. Network layer source and destination addresses - Responsible for delivering the IP packet from original source to the final destination. Data link layer source and destination addresses – Responsible for delivering the data link frame from one network interface card (NIC) to another NIC on the same network. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 45 Data Access Layer 3 Logical Address The IP packet contains two IP addresses: Source IP address - The IP address of the sending device, original source of the packet. Destination IP address - The IP address of the receiving device, final destination of the packet. These addresses may be on the same link or remote. © Cisco and/or its affiliates. All rights reserved. Cisco Confidential 46 Data Access Layer 3 Logical Address (Cont.) An IP address contains two parts: Network portion (IPv4) or Prefix (IPv6) The left-most part of the