IT 271 Computer Networks Fundamentals PDF

IT 271 Computer Networks Fundamentals 1 Module 1 Explaining Network Topologies 2 Learning Objectives Explain network types and characteristics. Compare and contrast OSI model layers. Configure SOHO networks. Explain CompTIA...

IT 271 Computer Networks Fundamentals 1 Module 1 Explaining Network Topologies 2 Learning Objectives Explain network types and characteristics. Compare and contrast OSI model layers. Configure SOHO networks. Explain CompTIA’s troubleshooting methodology. 3 Lesson 1.1 Networking Overview 4 Think About It How would you define your social network? 5 How are Personal and IT Networks Similar? Social Network IT Network A collection of computers and A collection of friends, family, other devices connected by coworkers, and acquaintances transmission medium Provides emotional support, Provides an opportunity for advice, and opportunities in shared resources personal matters Helps in communication, Helps with communication information sharing, and and information sharing in a social connections digital environment 6 What’s A computer Network ? "A computer network is a system of interconnected devices that communicate using standard protocols to share resources, exchange data, and provide services, using wired or wireless connection." 7 Networks working architecture Peer-to-Peer Client-Server 8 Networks working architecture (Cont’d) 1. Peer-to-Peer (P2P) Network In a P2P network, each device (called a peer) is both a client and a server. All devices in the network have equal responsibilities and can directly communicate with each other, sharing resources without a central authority. It is typically used in smaller networks or for specific applications like file sharing. Advantages: Simple to set up. No need for a central server. Each device can act as a server Disadvantages: Not as scalable for large networks. Limited security and management features. 9 Networks working architecture (Cont’d) 2. Client-Server Network In a Client-Server network, there is a clear distinction between the client and the server. The server is a central system that manages resources, and clients are devices (e.g., computers, smartphones) that request services or resources from the server. It is widely used in larger, more complex networks, such as corporate environments and web applications (e.g., websites, email servers). Advantages: Centralized control and management. Easier to secure and manage, especially for large networks. Better suited for scalability and handling large amounts of traffic. Disadvantages: Requires dedicated servers and more complex setup. If the server goes down, clients lose access to resources. 10 Peer-to-Peer Client-Server 11 Network classification by size and coverage area Network Type Definition Example Range A network for personal devices Bluetooth connection between a PAN (Personal Area Network) A few meters (around a person). within a small area. phone and smartwatch. A network that connects devices Office network with computers and Up to several kilometers (building LAN (Local Area Network) within a limited area such as a printers connected to a router. or campus). building. Company branches within a city MAN (Metropolitan Area A network that covers a city or Up to tens of kilometers (city- connected via network Network) large campus. wide). infrastructure. A network that covers broad The Internet, connecting networks Can cover countries, continents, WAN (Wide Area Network) areas, connecting multiple LANs. across the world. or even globally. 12 Local Area Networks A local area network (LAN) is confined to a single geographical location. SOHO Enterprise LAN Datacenter 13 Activity: Quick Search Point-to-Point Star Topology Topology Mesh Topology 14 Network Topologies Topology Description Advantages Disadvantages Example If the backbone fails, the All devices share a single Simple to set up, uses less cabling whole network goes down; Bus communication line or backbone, Early Ethernet networks. than other topologies. performance decreases with and data is sent to all devices. more devices. Devices are connected in a A failure in any one Fiber Distributed Data circular loop, with data traveling in Easy to install and troubleshoot, Ring connection can disrupt the Interface (FDDI) and some one direction until it reaches its predictable data transmission times. entire network. LANs. destination. Every device is connected to Expensive and complex to High redundancy, reliable, no single Military and mission-critical Mesh every other device, allowing set up due to the number of point of failure. networks. multiple paths for data to travel. connections needed. All devices are connected to a Easy to manage and troubleshoot, Central hub is a single point Most modern home and Star central hub or switch, which failure of one device doesn’t affect of failure; if it goes down, the office networks using routers manages data flow. the network. entire network is affected. or switches. 15 Network Topologies Ring Bus Star Mesh 16 Network Topologies: Point-to-Point 17 Network Topologies: Star 18 Lesson Summary Network: Connected devices sharing data (computers, protocols, transmission medium) Client-Server Network: Central server provides resources and services to client devices Local Area Network (LAN): Connects devices within a limited area (home, office) Network Topology: Layout of connections between network devices (star, mesh, point-to-point) 19 Lesson 1.2 OSI Model Concepts 20 The OSI Model Packet Flow 7 Application 1 Physical Sender Receiver 6 Presentation 2 Data Link 5 Session 3 Network 4 Transport 4 Transport 3 Network 5 Session 2 Data Link 6 Presentation 1 Physical 7 Application 21 The OSI Model Mnemonic Please Do Not Throw Sausage Pizza Away P D N T S P A Physical Data Link Network Transport Session Presentation Application 22 Responsibility of the Network 7 Application 6 Presentation 5 Session 4 Transport 3 Network Responsibility 2 Data Link of the Network 1 Physical 23 Layer 1 – Physical 7 Application Functions and Examples Transmit bits from sending source over network 6 Presentation communications to physical layer of receiving device Data transmitted using cables or wireless media 5 Session Examples: Coax and fiber cables, hubs and repeaters, modem, transceiver 4 Transport 3 Network 2 Data Link Bit Stream Sender Receiver 1 Physical 24 Layer 2 – Data Link 7 Application Functions and Examples 6 Presentation Transfers data between nodes on the same logical segment using hardware addresses 5 Session Encapsulation: organizes stream of bits arriving from the Physical layer into frames Examples: NIC, bridge, switch, wireless access point 4 Transport 3 Network G1 Host AA 2 Data Link G2 Host AB 1 Physical G3 Host AC 25 Layer 3 – Network Functions and Examples 7 Application Moving data around a network of networks 6 Presentation using network and host IDs Packets given a destination IP address and 5 Session forwarded to the destination network Examples: Router, IP, ACL, Basic Firewall 4 Transport 3 Network Network 9 2 Data Link Router A Router B: 1.254 2.254 1 Physical Network 1 Network 1 (Hosts 1.1, 1.2, 1.3) (Hosts 2.1, 2.2, 2.3) 26 Layer 4 - Transport 7 Application Functions and Examples 6 Presentation Tracks communication between applications on source and destination hosts 5 Session Segments data and manages each data piece Reassembles segments into application data 4 Transport Examples: Multilayer switches, advanced 3 Network firewalls, intrusion detection systems (IDSs) 2 Data Link 1 Physical 27 Layer 4 – Transport 28 Responsibility of Host 7 Application Responsibility 6 Presentation of the Host 5 Session 4 Transport 3 Network 2 Data Link 1 Physical 29 Layer 5 - Session 7 Application Functions and Examples 6 Presentation Establishes and manages the 5 Session connections between applications Examples: ASP, ADSP, NetBIOS, PAP 4 Transport 3 Network Authentication Request 2 Data Link Session Established 1 Physical Respond 30 Layer 6 - Presentation Functions and Examples 7 Application Delivers data across network 6 Presentation connections Examples: MIME, 5 Session Encryption/Decryption Services 4 Transport Application Layer Data Application Layer Data 3 Network Presentation Layer Presentation Layer 2 Data Link Decrypted, Decoded, and Encrypted, Encoded, Compressed Decompressed 1 Physical Session Layer Data Session Layer Data 24 Layer 7 - Application Functions and Examples 7 Application Interacts directly with end-user’s 6 Presentation software applications for network 5 Session service Examples: SMTP, DNS, FTP 4 Transport 3 Network 2 Data Link Human Machine 1 Physical Readable Readable 32 Activity: Unscramble the OSI Model Network Physical Presentation Physical Data Link Network Transport Session Presentation Application 33 Lesson 1.3 SOHO Networks 34 Think About It What is a SOHO router? And what is it used for? 35 SOHO Router – Physical Layer 36 SOHO Router – Data Link Layer Ethernet switch Wireless access point Each host interface identified by a MAC address 37 SOHO Router – Network Layer Forwards between local private network and public internet Runs a DHCP server to provide each host with an IP address Router’s WAN interface given a public IP address 38 SOHO Router – Transport and Application Application Layer Request and Response Transport Transport Layer Layer Segmentation Reassembly 39 SOHO Router – The Internet WAN: SOHO connection to Internet Public switched telephone network (PSTN) High-bandwidth trunks connecting IXPs ISP links between networks in IXP datacenter 40 Binary Numbers – Base 10 Ten-millions One- Hundred- Ten- One- Hundreds Tens Ones millions thousands thousands thousands Digit Digit Digit Digit Digit Digit Digit Digit x 10,000,000 x 1,000,000 x x x x x x 100,000 10,000 1,000 100 10 1 41 Binary Numbers – Base 10 128 64 32 16 8 4 2 1 Digit x 128 Digit x 64 Digit x 32 Digit x 16 Digit x 8 Digit x 4 Digit x 2 Digit x 1 42 Binary Conversion Let's look at how to convert 205 into binary. 128 64 32 16 8 4 2 1 Digit x 128 Digit x 64 Digit x 32 Digit x 16 Digit x 8 Digit x 4 Digit x 2 Digit x 1 1 1 0 0 1 1 0 1 43 Activity: Binary Conversion Convert 132 into binary. 128 64 32 16 8 4 2 1 Digit x 128 Digit x 64 Digit x 32 Digit x 16 Digit x 8 Digit x 4 Digit x 2 Digit x 1 1 0 0 0 0 1 0 0 44 Lesson 1.4 Troubleshooting Methodology 45 Discussion: Think About It What is troubleshooting? What steps should be involved in the troubleshooting process? 46 Troubleshooting Methodology Document Establish a Test the Identify Establish a Implement findings, theory of theory to Verify the the plan of the actions, probable determine solution problem action solution and cause cause outcomes 47 Identify the Problem Gather information System documentation Installation and maintenance logs Vendor support sites Question users Open questions to uncover information Closed question to invite a yes or no or fixed response 48 Identify Problem Symptoms Identify symptoms Physical inspection Logs and diagnostic software Try to duplicate the problem Determine if anything has changed Did it ever work? What has changed since it was last working? Approach problems individually Verify symptoms are related before treating them as one single issue 49 Establish a Theory of Probable Cause Troubleshooting styles Question the obvious Methodically prove the functionality of each component OSI Model Approach Top-down approach Bottom-up approach 50 Test the Theory to Determine the Cause Question the obvious Use one or more method-based approaches Don’t jump to conclusions Escalation Problem is beyond your knowledge or ability Problem falls under a system warranty Scope of the problem is very large Customer is difficult or abusive 51 Implement, Verify, and Document Implement changes Implement fixes Escalate if higher authorization is needed Verify the solution Make sure the system seems to work for you Make sure the system seems to work for customer Document Document findings, actions, and outcomes Logs are useful for future troubleshooting 52 Activity: Troubleshooting Several office employees report their computers are unable to connect to the Internet, affecting workflow and productivity. Document Establish a Test the Identify Establish a Implement findings, theory of theory to Verify the the plan of the actions, probable determine solution problem action solution and cause cause outcomes 53 Summary Remember OSI model’s 7 layers (physical, data link, network, transport, session, presentation, and application) Plan network structure and troubleshoot issues using OSI model layers Implement methodical approach to troubleshooting (identification, planning, execution, verification, and documentation) Use strategies like top-to-bottom, bottom-to-top, and divide-and- conquer 54 Module 2 Supporting Cabling and Physical Installations 1 Learning Objectives Summarize Ethernet standards. Summarize copper cabling and connector types. Summarize fiber optic cabling and connector types. Describe physical installation factors for rack-based installations in server rooms and datacenters. Deploy and troubleshoot Ethernet cabling. 2 Lesson 2.1 Ethernet 3 Network Data Transmission Terms Data transmission is Data is sent point-to Digital signals (1s and 0s) transferring data from point via wired or are transmitted across wireless streams or one device to another. the channels. channels. Transmission media Error The speed at which the include copper wires, detection/correction data is sent is the data fiber optic cables, or mechanisms detect transfer rate. wireless signals. transmission errors. 4 Ethernet Standards IEEE 802.3 standards define the physical layer and data link layer’s media access control (MAC) for wired Ethernet. Standard Cables Speed 10Base-T Unshielded twisted pair (UTP) 10 Mbps 100Base-T Cat5e or higher 100 Mbps 1000Base-T Cat6 or higher 1000 Mbps Gigabit Ethernet 10GBase-T Cat6 or higher 10 Gbps 10 Gigabit Ethernet 100Base-TX Cat5 or higher 100 Mbps Fast Ethernet 5 Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Collision Purpose Process Resolution Detection Carrier Sense Jam Signal Regulates If two devices communication transmit in networks with simultaneously, shared a collision is transmission detected. mediums Backoff Multiple Access Algorithm 6 CSMA/CD Diagram 7 Fiber Ethernet Standards Standard Cables Speed 100Base-FX MMF (OM1) 100 Mbps 100Base-SX MMF (OM1, OM2) 100 Mbps 1000Base-SX MMF (OM2, OM3) 1 Gbps 1000Base-LX MMF (OM1, OM2, OM3), SMF 1 Gbps (OS1, OS2) 10GBase-SR MMF (OM2, OM3, OM4) 10 Gbps 10GBase-LR SMF (OS1,OS2) 10 Gbps 8 Activity: True or False CSMA/CD regulates communication in networks with shared transmission media. 9 Lesson 2.2 Copper Cables and Connectors 10 Unshielded Twisted Pair (UTP) Structure Contains 2 to 1800 pairs in a plastic jacket Interference Minimal EMI protection Use Popular for LANs because it is cost-effective Categories Grades like Cat5e (1 Gbps) and Cat6a (10 Gbps) Installation Avoid sharp bends, keep away from EMI sources 11 Shielded Twisted Pair Cable (STP) Structure Interference Use Categories Installation High- Twisted EMI Grades such Careful interference copper wires protection as Cat5e, 6, 7 handling areas Sensitive Conductive Reduced Avoid sharp data shielding crosstalk bends transmission 12 Ethernet Connectors Feature RJ11 RJ45 Image Configuration 6 positions, 4 connectors 8 positions, 8 connectors Usage Phone and modem Computer networking Bandwidth 24 Mbps 10 Gbps over Ethernet 13 Plenum and Riser-Rated Cable Plenum-rated Riser-rated Used in vertical spaces Installed in plenum spaces between floors Made of fire-resistant low toxic Fire-resistant materials Meets higher fire safety Prevent spread of fire between standards floors More expensive More cost-effective 14 Coaxial and Twinaxial Cable Feature Coaxial Twinaxial Image Configuration Central conductor, insulation, metallic Two inner conductors in a twisted shield, outer jacket pair, insulation, outer jacket Usage TV, Internet, radio signals, CCTV 10 GB Ethernet networks Bandwidth Wide range of frequencies, high-speed Very-short range high-speed data transmission Connectors BNC, TNC, SMA Proprietary 15 Activity: Multiple Choice A company is setting up a network in an industrial environment where machinery often causes significant electromagnetic interference. The network requires a cabling solution that can handle high-speed data transfer while also being resistant to this interference. The cable will be used to connect servers within the same data center, and the runs will not exceed 100 meters. A. Unshielded Twisted Pair (UTP) B. Shielded Twisted Pair (STP) C. Coaxial Cable D. Fiber Optic Cable 16 Lesson 2.3 Wiring Implementation 17  Structured Cabling System A structured cabling scheme is a standard way of provisioning cabled networking for computers in an office building. Work Area User connection point Floor-level networking Horizontal Cabling Multiple IDFs Telecommunications Equipment hub Room Dedicated space Backbone Cabling Vertical connections Entrance Network transition point Facilities/Demarc LEC integration 18 Structured Cabling Diagram 19 T568A and T568B Termination Standards 20 Patch Panels Wiring Purpose Structure Function Standards Facilitates Punch down IDC terminals Supports T568A cable blocks at rear allow for wiring schemes management for cable secure and Supports T568B termination compact cable wiring schemes RJ45 ports in termination front for device RJ45 ports connections enable easy reconfiguration of network connections 21 Structured Cable Installation Pulling Cable Connection Documentation Gather tools Service loop Verify Plan route Label cables Cut and label Patch panel connections Record details Route cables Work area Test network Bundle cables Preparation Termination Testing 22 Termination Tools Cable Cutters Crimp Tools For clean cuts To attach of the cable connectors to without the cable damaging ends. wires. Punch-Down Tools Cable Strippers For For safely terminating removing cable wires in insulation punch down without blocks. nicking wires. 23 Activity: What is it? 1 2 3 4 24 Lesson 2.4 Fiber Optic Cables and Connectors 25 Fiber Optic Considerations Fiber optic cables Thin stands of glass or plastic Transmit data using light pulses Composition Core: ultra-pure strands of glass Cladding: reflects light back into the core Buffer: outer protective jacket Benefits Transmit data up to 800 Gbps Maintain signal quality over long distances Immune to electromagnetic interference 26 Single Mode and Multimode Fiber Factor Single Mode Multimode Core diameter Small core allowing only one light Larger core allowing multiple light to pass through modes to pass through Light transmission Light travels directly down the fiber Light bounces more causing more with minimal reflection and dispersion and attenuation attenuation Distance and Suitable for long distances Best for shorter distances bandwidth Applications Long-haul networks, high-speed Datacenters, LANs broadband, telecommunications Cost More expensive Less expensive 27 Fiber Optic Connector Types Factor Subscriber Connector Lucent Connector (LC) Straight Tip Connector (SC) (ST) Image Ferrule Size 2.5 mm 1.25 mm 2.5 mm Applications Telecommunications Heavily populated patch LANS and datacenters networks, data panels and cabinets transmission Features Push-pull design, quick Square shape, duplex Bayonet twist-lock, older deployment, low insertion header design but still widely used loss, durability 28 Wavelength Division Multiplexing (WDM) Allows multiple data channels to share the same fiber using different wavelengths of light Bidirectional WDM Coarse WDM (CWDM): Dense WDM (DWDM): (BiDi): Supports Tx and Rx over the Supports up to 16 wavelengths Provisions more channels (20, same fiber strand Typically used for 4-8 40, 80, or 160) Uses shifted wavelengths bidirectional channels on a Requires precise lasers due to (1310 nm for Tx, 1490 nm for single strand less spacing between channels Rx) Can also be used for Supports multi-channel Requires installation in unidirectional channels on 1G, 10G, and 40G Ethernet opposite pairs dual strands links Documented in Ethernet Transceivers installed in standards (1000BASE-BX, opposite pairs for proper 10GBASE-BX) function 29 Activity: Two Truths and a Lie Fiber optic cables are Single mode fiber made of thin strands causes more of glass or plastic that dispersion and transmit data using attenuation then light pulses multimode fiber Lucent connectors are often used for heavily populated patch panels 30 Lesson 2.5 Physical Installation Factors 31 Rack Systems Secure Areas: Telecommunications closets, equipment rooms, server rooms Datacenters for server provisioning Access Control: Physical access controls for authorized entry Rack Installation: Steel shelving systems for standard-size equipment Secure, compact storage; increased density Standard Sizing: EIA standard 19"/48.26 cm width for rack-mounting 32 Humidity and Temperature Temperature Humidity Electrical Flood Monitoring Control Stability Detection Avoids Ensures Identifies Prevents condensation uninterrupted water-related overheating and corrosion power supply risks Triggers Ensures Monitors for Reduces static immediate effective heat voltage charge risks system dissipation irregularities shutdowns 33 Power Management Power Load and Battery PDUs Essentials Voltage Backups Component-level Essential stable storage device AC circuits aligned Ensure clean power protection power for network with equipment load signals appliances UPS for system-level power continuity Protection against High-voltage circuits Offer remote voltage spikes, UPS runtime in datacenters monitoring/control surges, and failures dependent on load/model Copyright © 2024 The Compu ng Technology Industry Associa on, Inc. All rights 34 reserved. Fire Suppression Fire Safety Detection and Sprinkler Sprinkler Extinguishers: Elements Alarms Systems Alternatives Clearly marked Dry-pipe fire exits. Various types for Heat-triggered, different fire water discharge. classes. Automatic and Pre-action Regular manual emergency smoke/fire evacuation drills. detection Halon (phased systems. out). Class C Risk of burst extinguishers for pipes, accidental Fire-resistant electrical safety. triggering. building design. Clean agent 35 Activity: Prevention What would you do to: Prevent equipment from overheating in server room Prevent static discharge Protect equipment and data from brownouts and blackouts 36 Lesson 2.6 Cable Troubleshooting 37 Specifications and Limitations: Part One Understanding Speed vs. Throughput Specifications Throughput Factors Compare Physical Layer: Average data expected vs. Symbols transfer rate over actual transmitted, time performance measured in Affected by Assess speed, baud rate (Hz) encoding, errors, throughput, Data Link Layer: distance, distance Nominal bit rate interference or bandwidth (bps) 38 Specifications and Limitations: Part Two Measurement Layers Latency Distance Limitations Network/Transport Speed of packet Media type dictates Layer: Throughput delivery, measured bit rate over Application Layer: in milliseconds (ms) distance Goodput Also known as Attenuation (dB (accounting for latency or delay loss) and packet loss) interference (SNR) impact performance 39 Cable Issues: Symptoms Random Slow Internet disconnections Connection speeds and timeouts reconnections Lagging Frequent drops Slowing down audio/video or unstable of applications communication network link 40 Cable Issues: Troubleshooting Use Substitute Test Check alternative Verify Physical Verify patch patch cords transceivers structured hosts or drivers and inspection cord with known with a cabling with switch ports network of cables connections good ones loopback appropriate to test adapter if faulty tool tools connectivity 41 Cable Testers Diagnosis with Cable Testing Tools Used when cable is not directly accessible Diagnose intermittent connectivity or performance issues Cable Tester Functions Reports on physical and electrical properties Tests conditions, crosstalk, attenuation, noise, resistance 42 Wire Map Testers and Tone Generators Wire Map Testers Tone Generators Detect improper cable Trace cables through termination walls or identify active Use base and remote cables in a bundle units to test each wire Known as “Fox and conductor Hound” Identify issues like open Apply signal to trace circuits, shorts, and cable with a probe incorrect pin-outs 43 Attenuation Issues Loss of signal strength in networking cables or connections (measured in decibels (dB) or voltage) Signal strength loss during transmission Higher impedance, higher attenuation Issues Long cabling distance Thin wire size Environmental factors Shorten cable lengths Solutions Use repeaters/extenders Upgrade to high-quality cables Measure and test signal attenuation at installation 44 Interference Issues Negative effects of electromagnetic, radio frequency, and electrostatic signals on cable transmissions Electromagnetic interference (EMI) Issues Radio frequency interference (RFI) Crosstalk from adjacent wires Defective connectors/conductors Shielding techniques (foil/braided shields) Solutions Systematic cable routing and organization Use robust materials and strain relief Compatibility testing 45 Crosstalk Issues Interference caused by signal overlap cables Crosstalk at transmitter Near End Crosstalk (NEXT) Caused by untwisting, faulty shields Attenuation to Crosstalk Insertion loss vs. NEXT Radio, Near End (ACRN) High value: strong signal Attenuation to Crosstalk FEXT at recipient end Radio, Far End (ACRF) Independent of link length For Gigabit/10 GbE Ethernet Power Sum Ensures cable suitability Interference from nearby cables Alien Crosstalk: Due to tight bundling, bad termination 46 Crosstalk Issues: Solutions Check for physical damage and improper installation Avoid excessive untwisting Ensure proper bundling Use appropriate cable types and connectors 47 Activity: Think About It What are some symptoms of cabling issues? 48 Summary Understand Cable Needs: Consider factors like interference and attenuation when choosing shielded copper or fiber optic cables Proper Cable Preparation: Use appropriate tools for cable preparation and termination for connectors or punch down blocks Application-Specific Use: Ensure cables are used for their intended purpose to meet network requirements. Cable Testing: Verify cable integrity using appropriate testing tools to identify and troubleshoot faults 49 Module 3 Configuring Interfaces and Switches 1 Learning Objectives Deploy networking devices. Explain network interfaces. Deploy common Ethernet switching features. Troubleshoot transceiver switching issues. 2 Lesson 3.1 Network Interfaces 3 Think About It: Network Interfaces What is a network interface? 4 Network Interface Cards A network interface card (NIC): Transceiver component Connects the host to a transmission medium (wired or wireless) Can have multiple ports on same card Has a unique MAC address Operates at the Data Link layer 5 Symptoms of NIC Issues Common symptoms of NIC issues include: Network connectivity failure Slow network speeds Intermittent connectivity Device manager error messages Network setting error messages 6 Modular Transceivers Modular transceivers Terminate multiple types of cable and connector types Operate at the Data Link layer 7 Symptoms of Transceiver Issues Mismatched ports No link Intermittent connection loss Signal strength Intermittent connections Packet loss Poor network performance 8  Ethernet Frame Format Preamble SFD Destination Source Ether Type Payload FCS (7 Bytes) (1 Byte) MAC MAC (2 Bytes) (46-1500 (4 Bytes) (6 Bytes) (6 Bytes) Bytes) Synchronization Signals the Protocol of Error- sequence start of the Address of Address of the the payload Data being checking frame the recipient sending transmitted code device device 9 MAC Address Format Device ID Organizationally unique identifier (based on device model and (OUI) manufactured date) 2D:45:19:87:C8:E2 48-bit alphanumeric identifier; pairs of hexadecimal digits separated by colons or hyphens 10  MAC Broadcast Address Preamble SFD Destination Source Ether Type Payload FCS MAC MAC Synchronization Signals the Protocol of Data being Error- sequence start of the Address of Address of the the payload transmitted checking frame the recipient sending code device device Broadcast Address 11:11:11:11:11:11 If MAC address is all 1s, all hosts on that network will receive and process the packet 11 Lesson 3.2 Ethernet Switches 12 Hubs Hub To: D From: A Not Not Mine! Mine. Mine. A B C D Hubs send transmissions from one port to every other port. 13 Bridges Bridges separate physical network segments while keeping all nodes in the same logical network. 14 Switches Switch To: D From: A A B C D A switch sends transmissions from one port only to the destination port. 15 Ethernet Switch Types Unmanaged Modular vs. Desktop vs. Stackable vs. Managed Fixed Rack Modular can be Managed configured with Can be Desktop switches switches can be different connected are free standing configured numbers and together types of ports Unmanaged Rack-mounted Fixed come with switches have no switches are Can be managed a set number of configuration designed fit into as a single unit ports options networking racks 16 Activity: Matching Hub Switch Bridge Improves network efficiency by dividing it into smaller, manageable sections 17 Activity: Matching Hub Switch Bridge Operates by creating a single shared communication path between multiple devices in a network 18 Activity: Matching Hub Switch Bridge Intelligently directs data to a specific port based on MAC addresses, reducing network congestion 19 Activity: Matching Hub Switch Bridge Operates primarily at the physical layer 20 Activity: Matching Hub Switch Bridge Learns the MAC addresses of devices connected to it and uses this information to forward data only to the intended recipient 21 Lesson 3.3 Switch Port Configuration 22 Link Aggregation/NIC Teaming Link aggregation Combining 2+ separate cabled links into a single logical channel Provides redundancy Cost effective 23 Maximum Transmission Unit Standard ethernet frame Maximum transmission unit (MTU) is 1,500 bytes Jumbo frame Supports payload up to 9.216 bytes Reduces the number of frames transmitted Limited because they break Ethernet standards 24 Spanning Tree Protocol Spanning Tree Protocol (STP) Layer 2 protocol Prevents bridge loops Provides fault tolerance 25 Power Over Ethernet Power over Ethernet (PoE) Allows 1 cable to transmit both data and power to networked devices Simplifies network installation and expansion 26 Activity: Scavenger Hunt Find devices that use Power over Ethernet (PoE). Explore to find any devices that might be powered through an Ethernet cable. Note the device type, device location, and how it benefits from PoE 27 Lesson 3.4 Switch Troubleshooting 28 Hardware Failure Issues Hardware Failure Issue Troubleshooting and Mitigation Steps Power issues Verify stable power supply Install UPS and secondary power sources Network adapters Check for damaged ports or connectors Test with alternative adapter if possible Update or reinstall drivers Switches/routers/modems Visually inspect for damage Inspect indicator lights Verify power supply and cabling connections Restart the device following proper protocols Overheating Check for proper ventilation around the device Clean dust from intake or exhaust vents Ensure cooling systems are operational 29 Port Status Indicators Solid green The link is connected, but there is no traffic Flickering green The link is operating normally (with traffic). The blink rate indicates the link speed No light The link is not working, or the port is shut down Solid amber The port is blocked by the spanning tree algorithm Blinking amber A fault has been detected 30 Switch Show Commands Show config Device's current configuration Configuration device will use Show startup-config upon the next restart Active configuration currently Show running-config used by the device Detailed information about the Show interface device's network interfaces 31 Switch Show Command Status Down/down Both the layer 1 (physical) and layer 2 (data link) connections are inactive. Administratively down/down The interface has been manually disabled by an administrator using the shutdown command Down/error disabled The interface has been automatically disabled due to a network error or policy violation Up/down (suspended) The physical layer is operational, but the data link layer is inactive due to administrative settings or errors 32 Interface Error Counters Link state Checks if interface is up or down Immediate alert for downtime Resets Count of manual and automatic restarts High frequency of resets should be monitored Discards/drops Causes by checksum errors, mismatched MTUs, size anomalies, high load, ACL or VLAN configuration errors Used for troubleshooting 33 Common Interface Errors Cyclic Redundancy Runt Frame Errors Giant Frame Errors Check (CRC) Errors Frame's calculated checksum does not Frames are smaller Frames exceed the match the than the minimum maximum allowed transmitted frame size. size. checksum Indicative of noise, Caused by Results from interference, or misconfiguration or collisions or damaged equipment malfunctioning hardware. malfunctions network devices 34  Network Loop and Broadcast Storm Network Loops: Network Loops: Broadcast Broadcast Causes Solutions Storms: Causes Storms: Solutions Redundant Proper DHCP issues Monitor DHCP connections redundant Very large traffic End-device side connection broadcast Segment the configuration domains network Implement spanning tree protocol (STP) Educate users 35 Power Over Ethernet Issues Cabling Standard Power Budget Considerations Compatibility Management Must use Cat 5e or Devices must Switches have a better, recommend negotiate the limited power Cat 6A correct PoE mode budget (300–400W) Importance of (Alternative A, B, or Use "show power conductor thickness Four-pair) inline" command for (23 AWG > 24 AWG Challenges with monitoring for better devices only performance) supporting the first Shielded cabling PoE standard helps disperse heat efficiently 36 Activity: What Would You Do? The switch won’t power on. What troubleshooting steps would you take? 37 Summary NIC vs. Transceiver: NIC connects host to network (cable), transceiver adapts cable types Hub vs. Switch: Hub broadcasts to all devices, switch directs traffic to specific devices; bridge connects networks, keeps them logically unified STP: Prevents bridge loops and ensures network redundancy (Layer 2 protocol) 38  Module 4 Configuring Network Addressing ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 1 reserved. Learning Objectives Explain IPv4 addressing schemes. Explain IPv4 forwarding. Configure IP networks and subnets. Use appropriate tools to test a host’s IP configuration. Explain IPv6 addressing schemes. Troubleshoot IP networks and hosts. ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 2 reserved.  Lesson 4.1 Internet Protocol Basics ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 3 reserved. Think About It What is the purpose of a package mailing label? What information is important to the delivery company? ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 4 IPv4 Datagram Header ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 5 Addressing and Forwarding ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 6  Address Resolution Protocol (ARP) I have a delivery for Let me find a Juanita Valdez her for you! ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 7 Access Subnet vs. Remote Using ARP ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 8 Unicast and Broadcast Addressing Unicast Addressed only to the destination IP Sends only to the destination Broadcast Addressed to the last IP address in a network or subnet Sends to all hosts on a network or subnet ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 9 Multicast and Anycast Addressing Multicast Addressed to a specific group of host IP addresses Sends to all hosts on a network or subnet Anycast Addressed to any one device out of a group of devices, typically the closest one Used for load balancing and redundancy ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 10 Activity: Two Truths and a Lie ARP functions like an IPv4 headers contain a online phone directory, "Destination" field used to associating IP addresses route data to the nearest with MAC addresses to server, regardless of its ensure data reaches the final destination. correct device. Broadcast addressing targets all hosts within a specified local network ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 11 reserved.  Lesson 4.2 IPv4 Addressing ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 12 reserved. IPv4 Addressing 172 17 154 2 101001100 00010001 10011010 00000010 8 bits 8 bits 8 bits 8 bits IPv4 addresses are decimal representations of four sets of binary octets. Each octet is 8 bits, making all IPv4 addresses 32 bits. ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 13 reserved. Activity: Binary Conversion Convert 11000011 into standard form: 0 1 1 0 0 0 0 1 128 64 32 16 8 4 2 1 Answer: 64 + 32 + 1 = 97 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 14 reserved. IP Address Formatting Network ID Host ID Like an apartment Like an apartment number within a building number building Common to all hosts on Identifies a host within the same IP network an IP network ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 15 reserved. Subnet Masks Subnet Masks Identifies the network portion of an IP address If network ID matches the local network, transmission is sent directly to host – otherwise it is forwarded Help devices determine which network or subnet it belongs ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 16 reserved. Determining Subnet Mask Example: Network: 192.168.1.x Binary: 11000000.10101000.00000001.00000000 Mask: 255.255.255.0 Binary: 11111111.11111111.11111111.00000000 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 17 reserved. Host Ranges 192.168.1.x 1.1 1.2 1.3 1.4 Think of the “network” part of an IP address as the building’s address, and the “host” part as the apartment number. ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 18 reserved. Host Ranges 192.168.1.x 1.2 1.3 1.4 1.5 Default Gateway 1.1 The default gateway is like the main entrance of lobby of the apartment building ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 19 reserved. Broadcast Addresses. 255 68.1 2.1 19 The broadcast address is like a loudspeaker intended to reach all residents in the apartment building. ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 20 reserved. Activity: Fill in the Blanks IP Address Subnet Mask Host Portion Broadcast Address 192.168.2.123 255.255.255.0.123 192.168.2.255 10.1.1.9 255.255.0.0.1.9 10.1.255.255 198.51.100.16 255.255.255.0.16 198.51.100.255 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 21 reserved.  Lesson 4.3 IPv4 Subnetting ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 22 reserved. Public vs. Private Addressing Public IP Addressing Private IP Addressing Assigned by ISPs Assigned by private Unique identification networks on Internet Unique identification Devices requiring in private network direct access to the Devices not directly Internet accessible from the Internet ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 23 reserved. Private IP Addresses Class Range A 10.0.0.0 to 10.255.255.255 B 172.16.0.0 to 172.31.255.255 C 192.168.0.0 to 192.168.255.255 D 224.0.0.0 to 239.255.255.255 E 240.0.0.0 to 255.255.255.255 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 24 reserved. IPv4 Address Scheme Design When planning a private IPv4 addressing scheme, consider: # of IP networks and subnetworks required # of hosts per subnet Network ID must be from a valid private range Network and host IDs cannot be all 1s (broadcast) Each host ID must be unique on subnet Each network ID must be unique on network ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 25 Classful Addressing ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 26 Classless Addressing Borrowing Bits Would have represented host information to represent network information Increase available network addresses Reduce usable host addresses in each subnet ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 27 reserved. 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 Classless Addressing Example Starting Network ID 192.168.89.0 Starting Subnet mask 255.255.255.0 Starting Network ID in binary 11000000.10101000.01011001.00000000 Borrow one bit from the host to give to the 11000000.10101000.01011001.00000000 network New network ID 192.168.89.128 Range of IP addresses 11000000.10101000.01011001.00000001 through 11000000.10101000.01011001.01111111 192.168.89.1 to 192.168.89.126 New subnet mask 255.255.255.128 or 192.168.89.128/25 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 58 reserved. Classless Inter-Domain Routing (CIDR) CIDR Allocates IP address space more efficiently Combines an IP address with a suffix (network portion of address) Allows for variable-length subnetting ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 59 reserved.  Variable Length Subnetting (VLSM) VLSM Creates subnets of different sizes within the same network Enables efficient allocation of IP addresses Requires careful planning and management ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 60 reserved. Activity: Classless Addressing Starting Network ID 192.168.89.0 Starting Subnet mask 255.255.255.0 Starting Network ID in binary 11000000.10101000.01011001.00000000 Borrow two bits from the host to give to the network 11000000.10101000.01011001.00000000 New network ID 192.168.89.192 Range of IP addresses 192.168.89.1 to 192.168.89.62 New subnet mask 255.255.255.192 or 192.168.89.192 /26 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 61 reserved.  Lesson 4.4 IP Troubleshooting Tools ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 62 reserved. ipconfig ipconfig ipconfig ipconfig ipconfig /all /renew /release View IP Also Renews the Releases the address, includes client’s client’s subnet mask, complete DHCPs leased DHCPs leased and default TCP/IP IP address IP address gateway for configuration all network parameters interfaces including DHCP and MAC address ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 63 reserved. Ifconfig and ip Reports network interface configuration: ip addr (legacy is ifconfig) Single interface only: ip addr show dev eth0 Status of interfaces: ip link Enable or disable an interface: ip link set eth0 up|down Modify the IP address configuration: ip addr add|delete ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 64 reserved. arp arp –a (or arp –g) Shows the ARP cache contents arp –s IPAddress MACAddress Adds an entry to the ARP cache arp –d Deletes all entries in the ARP cache ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 65 reserved. ping ping Tests connectivity with a given IP address Format: ping IPaddress ping error messaging Destination host unreachable No reply (request timed out) ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 66 reserved.  Lesson 4.5 IP version 6 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 67 reserved. IPv6 vs IPv4 Comparison IP Version 4 IP Version 6 Address format Dotted decimal format Hexadecimal format (192.168.1.1) (2001:0db8:85a3:0000:0000:8a2e:0370:7334) # of addresses 4.3 billion 340 undecillion (3.4 x 10^38) Network and Changes based on subnet First 64 bits are used for network ID. Host Portions mask Second 64 bits are used for host ID ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 68 reserved.  IPv6 Address Format Contains eight 16-bit numbers, with each double-byte expressed as 4 hex digits Binary Address 0010 0000 0000 0001 : 0000 1101 1011 1000 : 0000 0000 0000 0000 : 0000 0000 0000 0000 : 0000 1010 1011 1100 : 0000 0000 0000 0000 : 1101 1110 1111 0000 : 0001 0010 0011 0100 Hex Notation 2001:0db8:0000:0000:0abc:0000:def0:1234 Canonical Notation 2001:db8::abc:0:def0:1234 ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 69 reserved. IPv6 Unicast Addressing Globally scoped unicast addresses are routable over the Internet and are the equivalent of public IPv4 addresses. ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 70 reserved. IPv6 Link Local Addressing Link Local Addressing Span a single subnet and the equivalent of IPv4 private addressing Link local range is fe80::/10 Start with a leading fe80, with the next 54 bits set to 0, and the last 64 bits are the interface ID ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 71 reserved. IPv6 Packets ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 72 IPv6 Multicast and Anycast Addressing Multicast First 8 bits: indicate the address is within the multicast scope Next 4 bits: used to flag types of multicast Next 4 bits: determine the scope Final 112 bits: define multicast groups within that scope ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 73 reserved. IPv4 and IPv6 Transition Mechanisms Dual Stack Tunneling NAT64 Encapsulates IPv6 Allows IPv4 and IPv6 packets within IPv4 Translates IPv6 into to run simultaneously packets to traverse IPv4 and vice versa IPv4 networks Ideal for transitional Best for environments Useful for IPv6 islands periods where both transitioning to IPv6 IPv4 and IPv6 networks within an IPv4 network but still needing access are operational to IPv4 resources ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 74 reserved. Common IPv6 Address Prefixes ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights reserved. 75 Summary IP: Creates interconnected networks (interwork) using unique addresses. IPv4 Address: 32-bit address divided into four octets. Network Segment: Represented by a subnet at layer 3 (Network.) TCP/IP Utilities: Command-line tools for network configuration and communication monitoring. IPv6 Address: Eight 16-bit numbers expressed in hexadecimal format. ​Copyright © 2024 The Computing Technology Industry Association, Inc. All rights 76 reserved.