CompTIA Network+ Guide to Networks, Ninth Edition PDF

CompTIA Network+ Guide to Networks, Ninth Edition Module 1: Introduction to Networking Jill West, CompTIA Network+ Guide...

CompTIA Network+ Guide to Networks, Ninth Edition Module 1: Introduction to Networking Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Module Objectives By the end of this module, you should be able to: 1. Distinguish between peer-to-peer and client-server networks 2. Identify types of applications and protocols used on a network 3. Describe various networking hardware devices and the most common physical topologies 4. Describe the seven layers of the OSI model 5. Explain best practices for safety when working with networks and computers 6. Describe the seven-step troubleshooting model for troubleshooting network problems Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Network Models Topology describes how parts of a whole work together Physical topology mostly refers to a network’s hardware and how computers, other devices, and cables work together to form the physical network Logical topology refers to how software controls access to network resources It includes how users and software initially gain access to the network A network operating system (NOS) controls access to the entire network A NOS is required by client-server models Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Peer-to-Peer Network Model (1 of 2) In a peer-to-peer (P2P) network model the OS of each computer on the network is responsible for controlling access to its resources There is no centralized control Computers, called nodes or hosts, form a logical group of computers and users Each computer controls its own administration, resources, and security Advantages Simple configuration Less expensive compared to other network models Disadvantages Not scalable Not necessarily secure Not practical for large installations Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Peer-to-Peer Network Model (2 of 2) Figure 1-1 In a peer-to-peer network, no computer has more authority than another; each computer controls its own resources and communicates directly with other computers Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Client-Server Network Model (1 of 3) Resources are managed by the NOS via a centralized directory database A Windows domain is a logical group of computers that a Windows Server can control Active Directory (AD) is the centralized directory database that contains user account information and security for the entire group of computers A user can sign on to the network from any computer on the network and gain access to the resources that AD allows This process is managed by Active Directory Domain Services (AD DS) A computer making a request from another is called the client Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Client-Server Network Model (2 of 3) Figure 1-2 A Windows domain uses the client-server model to control access to the network, where security on each computer or device is controlled by a centralized database on a domain controller Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Client-Server Network Model (3 of 3) The NOS is responsible for: Managing client data and other resources Ensuring authorized user access Controlling user file access Restricting user network access Dictating computer communication rules Supplying applications and data files to clients Servers that have a NOS installed require: More memory, processing power, and storage capacity Equipped with special hardware to provide network management functions Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Client-Server Applications (1 of 2) Network services are the resources a network makes available to its users It includes applications and the data provided by these applications In client-server applications: A client computer requests data or a service from a second computer, called the server Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Client-Server Applications (2 of 2) Figure 1-3 A web browser (client application) requests a web page from a web server (server application); the web server returns the requested data to the client Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Network Services and Their Protocols (1 of 2) Protocols are methods and rules for communication between networked devices Two primary network protocols: TCP (Transmission Control Protocol) IP (Internet Protocol) Popular client-server applications include: Web service Email services DNS service FTP service Database services Remote access service Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Network Services and Their Protocols (2 of 2) Figure 1-5 SMTP is used to send email to a recipient’s email server, and POP3 or IMAP4 is used by the client to receive email Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Knowledge Check Activity 1-1 Which of these protocols could not be used to access a server in a nearby building? a. Telnet b. RDP c. TLS d. SSH Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Knowledge Check Activity 1-1: Answer Which of these protocols could not be used to access a server in a nearby building? Answer: c. TLS TLS (Transport Layer Security) adds encryption to other protocols, such as HTTP, but does not provide remote access to a computer Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Network Hardware Figure 1-7 This LAN has five computers, a network printer, a local printer, a scanner, and a switch, and uses a star topology Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  LANs and Their Hardware (1 of 4) A LAN (local area network) is usually contained in a small space A switch receives incoming data from one of its ports and redirects it to another port or multiple ports Will send the data to its intended destination The physical topology used by this network is called a star topology All devices connect to one central device (usually a switch) A NIC (network interface card) is a network port used to attach a device to a network Also called a network adapter A LAN can have several switches A backbone is a central conduit that connects the segments (pieces) of a network Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. LANs and Their Hardware (2 of 4) Figure 1-11 This local network has three switches and is using a hybrid topology Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  LANs and Their Hardware (3 of 4) A router is a device that manages traffic between two or more networks Can help find the best path for traffic to get from one network to another Routers can be used in small home networks to connect the home LAN to the Internet Called a SOHO (small office-home office) network Industrial-grade routers can have several network ports, one for each network it connects to Difference between router and switch: A router is like a gateway between networks and belongs to two or more local networks A switch belongs only to its local network Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. LANs and Their Hardware (4 of 4) Figure 1-14 (a) A router stands between the LAN and the Internet, connecting the two networks; (b) Home networks often use a combo device that works as both a switch and a router Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  MANs and WANs (1 of 2) A WAN (wide area network) is a group of LANs that spread over a wide geographical area A MAN (metropolitan area network) is a group of connected LANs in the same geographical area Also known as a campus area network (CAN) MANs and WANs often use different transmission methods and media than LANs PAN (personal area network) is a much smaller network of personal devices A network of personal devices such as your smartphone and your computer Other network types: BAN (body area network) SAN (storage area network) WLAN (wireless local area network) Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  MANs and WANs (2 of 2) Figure 1-17 A WAN connects two LANS in different geographical areas Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. The Seven-Layer OSI Model (1 of 2) Figure 1-18 A browser and web server communicate by way of the operating system and hardware, similar to how a letter is sent through the mail using the U.S. Postal Service and the road system Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. The Seven-Layer OSI Model (2 of 2) Figure 1-19 How software, protocols, and hardware map to the seven-layer OSI model Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Layer 7: Application Layer The application layer describes the interface between two applications, on separate computers Application layer protocols are used by programs that fall into two categories: Provide services to a user, such as a browser and Web server Utility programs that provide services to the system, such as SNMP (Simple Network Management Protocol) programs that monitor and gather information about network traffic Payload is the data that is passed between applications or utility programs and the OS Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Layer 6: Presentation Layer The presentation layer is responsible for reformatting, compressing, and/or encrypting data in a way that the receiving application can read Example: An email message can be encrypted at the Presentation layer by the email client or by the OS Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Layer 5: Session Layer The session layer describes how data between applications is synched and recovered if messages don’t arrive intact at the receiving application The application, presentation, and session layers are intertwined It is often difficult to distinguish between them Most tasks are performed by the OS when an application makes an API call to the OS An API (application programming interface) call is the method an application uses when it makes a request of the OS Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Layer 4: Transport Layer The transport layer is responsible for transporting Application layer payloads from one application to another Two main Transport layer protocols are: TCP (Transmission Control Protocol) - makes a connection with the end host, checks whether data was received; called a connection-oriented protocol UDP (User Datagram Protocol) - does not guarantee delivery by first connecting and checking whether data is received; called a connectionless protocol Protocols add control information in an area at the beginning of the payload (called header) Encapsulation is the process of adding a header to the data inherited from the layer above The Transport layer header addresses the receiving application by a number called a port If a message is too large, TCP divides it into smaller messages called segments In UDP, the message is called a datagram Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Layer 3: Network Layer The network layer is responsible for moving messages from one node to another until they reach the destination host The principal protocol used by this layer is IP (Internet Protocol) IP adds its own network layer header to the segment or datagram The entire network layer message is called a packet An IP address is an address assigned to each node on a network The network layer uses it to uniquely identify each host IP relies on several routing protocols to find the best route for a packet to take to reach destination ICMP and ARP are examples Network layer protocol will divide large packets into smaller packets in a process called fragmentation Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Layer 2: Data Link Layer Layers 2 and 1 are responsible for interfacing with physical hardware on the local network Protocols at these layers are programmed into firmware of a computer’s NIC and other hardware Type of networking hardware or technology used on a network determine the data link layer protocol used Ethernet and Wi-Fi are examples The data link layer puts control information in a data link layer header and at the end of the packet in a trailer The entire data link layer message is called a frame A MAC (Media Access Control) address is also called a physical address, hardware address, or data link layer address It is embedded on every network adapter Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Layer 1: Physical Layer The physical layer is responsible for sending bits via a wired or wireless transmission Bits can be transmitted as: Wavelengths in the air Voltage on a copper wire Light (via fiber-optic cabling) Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Protocol Data Unit or PDU Protocol data unit (PDU) is the technical name for a group of bits as it moves from one layer to the next and from one LAN to the next Technicians loosely call this group of bits a message or a transmission Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Summary of How the Layers Work Together Figure 1-20 Follow the red line to see how the OSI layers work when a browser makes a request to a web server Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Knowledge Check Activity 1-2 Which OSI layer adds both a header and a trailer? a. Transport layer b. Network layer c. Data link layer d. Physical layer Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Knowledge Check Activity 1-2: Answer Which OSI layer adds both a header and a trailer? Answer: c. Data link layer The data link layer puts its control information in a data link layer header and also attaches control information to the end of the packet in a trailer Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Safety Procedures and Policies Network and computer technicians need to know how to protect themselves As wells as protect sensitive electronic components This section takes a look at some best practices for safety Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Emergency Procedures Know the best escape route or emergency exit Fire Suppression Systems - have a fire suppression system in the data center that includes: Emergency alert system Portable fire extinguishers Emergency power-off switch Ask yourself: Does the security system allow access during a failure (fail open) or deny access during the failure (fail close)? An SDS (safety data sheet) explains how to properly handle substances such as chemical solvents and how to dispose of them Includes information such as identification, first-aid measures, fire-fighting measures, accidental release measures, handling and storage guidelines, exposure controls, and physical and chemical properties Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Safety Procedures (1 of 4) Electrical and tool safety is generally regulated by OSHA (Occupational Safety and Health Administration) OSHA guidelines when using power tools: Wear PPE (personal protective equipment) Keep all tools in good condition and properly store tools not in use Use the right tool for the job and operate the tool according to the manufacturer’s instructions Watch out for trip hazards, so you and others don’t stumble on a tool or cord Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Safety Procedures (2 of 4) Lifting Heavy Objects - follow these guidelines: Decide which side of object to face so load is most balanced Stand close to the object with your feet apart Keep your back straight, bend knees and grip load Lift with your legs, arms, and shoulders (not your back or stomach) Keep the load close to your body and avoid twisting your body while you’re holding it To put the object down, keep your back as straight as possible and lower object by bending your knees Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Safety Procedures (3 of 4) Protecting Against Static Electricity Computer components are grounded inside a computer case Grounding means that a device is connected directly to the earth Sensitive electronic components can be damaged by ESD (electrostatic discharge) Static electricity can cause two types of damage: Catastrophic failure - destroyed beyond use Upset failure - shorten the life of a component Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Safety Procedures (4 of 4) Before touching a component, ground yourself by: Wearing an ESD strap around your wrist that clips onto the chassis or computer case Touching the case before touching any component inside the case Storing a component inside an antistatic bag In addition to protecting against ESD, always shut down and unplug a computer before working inside it Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Troubleshooting Network Problems Troubleshooting steps used by most expert networking troubleshooters: Step 1: Identify the problem and its symptoms Step 2: Establish theory of probable cause Step 3: Test your theory to determine cause Step 4: Establish a plan for resolving the problem Step 5: Implement the solution or escalate the problem Step 6: Verify full functionality and implement preventative measures Step 7: Document findings, actions, outcomes Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Self-Assessment What networking hardware devices have you used in the past? What type of network or computer safety issues have you (or a friend or another student) experienced? How did you troubleshoot those issues? Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Summary Now that the lesson has ended, you should be able to: Distinguish between peer-to-peer and client-server networks Identify types of applications and protocols used on a network Describe various networking hardware devices and the most common physical topologies Describe the seven layers of the OSI model Explain best practices for safety when working with networks and computers Describe the seven-step troubleshooting model for troubleshooting network problems Jill West, CompTIA Network+ Guide to Networks, 9th Edition. © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.