Network Models PDF

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...

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.  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.  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.  Module Objectives By the end of this module, you should be able to: 1. Describe the roles of various network and cabling equipment in commercial buildings and work areas 2. Maintain network documentation 3. Manage changes made to 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.  Components of Structured Cabling ANSI/TIA-568 Commercial Building Wiring Standard Also known as structured cabling The wiring standard describes the best way to install networking media to maximize performance and minimize upkeep The principles apply no matter what type of media, transmission technology, or networking speeds are involved Structured cabling is based on a hierarchical design and assumes a network is based on the 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. From the Demarc to a Workstation (1 of 11) Figure 2-1 ANSI/TIA structured cabling in a campus network with three buildings 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.  From the Demarc to a Workstation (2 of 11) Entrance Facility in Building A: EF (entrance facility) – location where the incoming network (such as Internet) connects with the school or corporate network Demarc (demarcation point) – the device that marks where a telecommunications service provider’s network ends and the organization’s network begins MDF (main distribution frame) – the centralized point of interconnection for an organization’s LAN or WAN (also called MC or main cross connect) Data room – an enclosed space that hold network equipment (also called data closet, data center, equipment room, or telecommunications room) Rack – holds various network equipment Patch panel – a panel of data receptors which can be mounted to a wall or a rack A patch panel provides a central termination point when many patch cables converge in a single location 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. From the Demarc to a Workstation (3 of 11) Figure 2-2 ANSI/TIA structured cabling inside a building 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. From the Demarc to a Workstation (4 of 11) Figure 2-3 Demarc for Internet service to a campus network; this demark is located inside a small data room and connects the incoming fiber signal from the ISP with the campus’s Ethernet 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. From the Demarc to a Workstation (5 of 11) Figure 2-5 Patch panel on rack 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.  From the Demarc to a Workstation (6 of 11) Entrance Facility in Building A (continued): VoIP telephone equipment – VoIP (Voice over IP) is the use of any network to carry voice signals using TCP/IP protocols In one or more data rooms you might find the following: VoIP gateway VoIP PBX VoIP endpoints Data Room in Building B: IDF (intermediate distribution frame) – provides an intermediate connection between the MDF and end-user equipment on each floor and in each building Work Areas in All Three Buildings: Work area – encompasses workstations, printers, and other network devices Wall jacks – the ANSI/TIA standard calls for each wall jack to contain at least one voice and one data outlet 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. From the Demarc to a Workstation (7 of 11) Figure 2-7 VoIP equipment can connect VoIP phones to an analog telephone line or an analog phone system to the Internet; there are pros and cons to each approach 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. From the Demarc to a Workstation (8 of 11) Figure 2-9 Workstations branching off IDFs that branch off an MDF create an extended 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.  From the Demarc to a Workstation (9 of 11) Rack Systems Racks come in two-post and four-post varieties (though six-post racks are also available) Racks may be wall- or ceiling-mounted, freestanding on the floor, or bolted to the floor Consider the following when purchasing racks: Height – rack height is measured in rack units (RU or U) with the industry standard being 42U tall Width – equipment racks come in a standard 19-inch frame (19 inches wide) Depth – rack depths vary between manufacturers In data centers containing multiple rows of racks, a hot aisle/cold aisle layout pulls cool air from vents in the floor or from low-lying wall vents into rows of racks (see Figure 2-14) 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. From the Demarc to a Workstation (10 of 11) Figure 2-11 Open two-post racks and enclosed four-post racks 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. From the Demarc to a Workstation (11 of 11) Figure 2-14 Hot aisle/cold aisle rack layout 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.  Cabling (1 of 5) Types of Cables Patch cable – a relatively short length of cabling with connectors at both ends Horizontal cabling – connects workstations to the closest data room and to switches housed in the room Backbone cabling – consists of cables or wireless links that provide interconnection between the entrance facility and MDF and between MDF and IDFs Many network problems are the result of poor cable installations Pay close attention to the quality of cable connections and cable management 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.  Cabling (2 of 5) Figure 2-15 Horizontal cabling from a switch in a data room to workstations 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.  Cabling (3 of 5) Figure 2-16 A typical UTP cabling installation 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.  Cabling (4 of 5) Cable Management Termination – when terminating twisted-pair cabling, don’t leave more than 1 inch of exposed cable before a termination Bend radius – do not exceed the cable’s prescribed bend radius, which is the radius of the maximum arc into which you can loop a cable without impairing data transmission Continuity – use a cable tester to verify that each cable segment transmits data reliably Loosely cinch cables Cable coverings and conduits – avoid laying cables across a floor and use cord covers if they must be exposed EMI sources – install cable at least 3 feet away from fluorescent lights or other sources of EMI (electromagnetic interference) Plenum cabling – if running cable in the plenum (the area above the ceiling tile or below subflooring), make sure the cable sheath is plenum-rated 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.  Cabling (5 of 5) Cable Management (continued) Grounding - pay attention to grounding requirements Slack in cable runs Cable trays - use cable management devices such as cable trays, braided sleeving, and furniture grommets Patch panels - use patch panels to organize and connect lines Company standards and inventory Documentation Keep your cable plant documentation accessible Label every data jack or port, patch panel and connector Use color-coded cables for different purposes Update your documentation as you make changes to the 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.  Monitoring the Environment and Security Data rooms are often serviced by HVAC systems separate from the rest of the building Specialized products can monitor the critical factors of a data closet’s environment: Unacceptable temperature Humidity Airflow conditions Every data room should be locked with only limited IT personnel having keys Security cameras are suggested 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 Documentation Having up-to-date and detailed documentation of your network is essential for the following reasons: Makes communication with coworkers more efficient Speeds up troubleshooting efforts Puts information at your fingertips when facing similar problems in the future 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 Diagrams (1 of 6) Network diagrams are graphical representations of a network’s devices and connections They may show physical layout, logical topology, IP address reserves, names of major network devices, and types of transmission media Network mapping - the process of discovering and identifying the devices on a network Nmap – one of the most popular tools used for network mapping Zenmap – Nmap’s GUI option Cisco Systems set the standard for diagram symbols used to represent network devices 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 Diagrams (2 of 6) Figure 2-23 Nmap output in PowerShell using the nmap command 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 Diagrams (3 of 6) Figure 2-25 Network diagram using Cisco symbols 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 Diagrams (4 of 6) Network diagrams provide broad snapshots of a network’s physical or logical topology Useful for planning where to insert a new switch or determining how a particular router, gateway, or firewall interact Wiring schematic is a graphical representation of a network’s wired infrastructure In detailed form, it shows every wire necessary to interconnect network devices Rack diagram is a drawing that show devices stacked in a rack 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.  Network Diagrams (5 of 6) Figure 2-29 Wiring diagram 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 Diagrams (6 of 6) Figure 2-30 Typical devices installed on a rack 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.  Operating Procedures Essential documentation: Logical and physical connections on a network Inventory management IP address utilization Vendors Internal operating procedures Policies Standards Many corporations establish SOPs (standard operating procedures) to ensure consistency An organization could provide an internal website or database to hold this information 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.  Inventory Management System life cycle (SLC) is the process of designing, implementing, and maintaining an entire network SLC includes: Removal and disposal of outdated assets Addition of compatible, updated devices Inventory management is the monitoring and maintaining of all assets that make up a network Simplifies maintaining and upgrading a network Provides network administrators with information about the costs and benefits of certain types of hardware or software 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.  Labeling and Naming Conventions (1 of 3) Tips for labeling and naming conventions: Use names that are as descriptive as possible Only include fields that are essential in identifying the device Don’t overcomplicate the name with useless or redundant information Use established naming conventions Think big-picture-down-to-details Consider any security risks from details included in your naming convention Use color-coded cables and use cable tags to identify each cable’s purpose Label the ports and jacks that cables connect to Where labels won’t fit on the device, draw a simple diagram of each device that indicates how each port is used Use labels that are durable and are designed to stick to plastic and metal 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. Labeling and Naming Conventions (2 of 3) Figure 2-32 Labels on ports and tags on cables 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. Labeling and Naming Conventions (3 of 3) Figure 2-33 Simple diagram of a Cisco router with red labels identifying how five ports are used 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.  Business Documents (1 of 2) Standard business documents you may encounter: RFP (request for proposal) is a request to vendors to submit a proposal for a product or service your company wants to purchase MOU (memorandum of understanding) documents the intentions of two or more parties to enter into a binding agreement, or contract SOW (statement of work) documents in detail the work that must be completed for a particular project SLA (service-level agreement) is a legally binding contract or part of a contract that defines the aspects of a service provided to a customer Example: the service provided by an ISP 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.  Business Documents (2 of 2) Standard business documents you may encounter (continued): MSA (master service agreement) is a contract that defines the terms of future contracts between parties Examples include payment terms or arbitration arrangements MLA (master license agreement) grants a license from a creator, developer, or producer to a third party for the purposes of marketing or sublicensing, or distributing the product to consumers 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.  Change Management Managing change while maintaining network’s efficiency and availability requires good planning Network users need to know when to expect certain network resources to be unavailable Common software and hardware changes range from installing patches to replacing network backbone You may also need to know the change management documentation that might be required for an enterprise-scale 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.  Software and Hardware Changes (1 of 2) Four types of software changes: Installation – new software to be installed on relevant devices and incorporated with network resources Patch – a correction, improvement, or enhancement Upgrade – a major change to a software package that enhances the functionality and features of the software Rollback – also called backleveling or downgrading Process of reverting to a previous version after attempting to patch or upgrade it Hardware changes could include adding new security cameras, replacing workstations, installing new printers, and upgrading hardware 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.  Software and Hardware Changes (2 of 2) The same change management principles apply to any type of change: Process all changes through the proper channels Minimize negative impacts on business procedures Plan thoroughly to maximize the changes of a successful change on the first attempt Document each change throughout the process 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.  Change Management Documentation Generally, the larger an organization, the more documentation required when making changes You may need to do the following: Submit a change request document Understand and follow the approval process Follow project management procedures Provide additional documentation that could include: Network configuration IP address utilization Additions to the network Physical location changes Close the change 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. Work with MAC addresses 2. Configure TCP/IP settings on a computer, including IP address, subnet mask, default gateway, and DNS servers 3. Identify the ports of several common network protocols 4. Describe domain names and the name resolution process 5. Use command-line tools to troubleshoot common 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.  Addressing Overview There are four addressing methods: Data link layer MAC (Media Access Control) address is 48 bits, written as six pairs of hex numbers separated by colons It is also called a physical address MAC addresses are embedded on every NIC in the world Network layer IP (Internet Address) address can be used to find any computer in the world IPv4 addresses have 32 bits and are written as four decimal numbers called octets IPv6 addresses have 128 bits and are written as eight blocks of hexadecimal number Transport layer port numbers are used to find applications Application layer FQDNs, computer names, and host names Fully qualified domain name (FQDN) – a unique character-based name 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.  MAC Addresses (1 of 2) Traditional MAC addresses contain two parts The first 24 bits are known as the OUI (Organizationally Unique Identifier) or manufacturer-ID This part is assigned by the IEEE The last 24 bits make up the extension identifier or device ID Manufacturer’s assign each NIC a unique device ID Switches use MAC addresses to identify devices on the 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.  MAC Addresses (2 of 2) Figure 3-3 The switch learns the sending device’s MAC address 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.  IP Addresses Static IP addresses are assigned manually by the network administrator Dynamic IP addresses are automatically assigned by a DHCP server You’ll learn more about DHCP later in the chapter There are two types of IP addresses: IPv4 is a 32-bit address IPv6 is a 128-bit address 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.  IPv4 Addresses (1 of 4) A 32-bit IPv4 address is organized into four groups of 8 bits each (known as octets) Each of the four octets can be any number from 0 to 255 Some IP addresses are reserved Example of an IPv4 address: 72.56.105.12 Classful addressing The dividing line between the network and host portions is determined by the numerical range the IP address falls in Classful IPv4 addresses are divided into five classes: Class A, Class B, Class C, Class D, and Class E 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.  IPv4 Addresses (2 of 4) Class A, B, and C licensed IP addresses are available for use on the Internet These are called public IP addresses A company can use private IP addresses on its private networks The IANA recommends the following IP addresses be used for private networks: 10.0.0.0 through 10.255.255.255 172.16.0.0 through 172.31.255.255 192.168.0.0 through 192.168.255.255 Classless addressing allows the dividing line between network and host portions to fall anywhere along the string of binary bits in an IP address CIDR (Classless Interdomain Routing) notation takes the network ID or a host’s IP address and follows it with a forward slash (/) followed by the number of bits that are used for the network ID 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.  IPv4 Addresses (3 of 4) Network Address Translation (NAT) is a technique designed to conserve public IP addresses needed by a network Address translation is a process where a gateway device substitutes the private IP addresses with its own public address When these computers need access to other networks or Internet Port Address Translation (PAT) is the process of assigning a TCP port number to each ongoing session between a local host and Internet host Two variations of NAT to be aware of: SNAT (Source Network Address Translation) - the gateway assigns the same public IP address to a host each time it makes a request to access the Internet DNAT (Dynamic Network Address Translation) - the gateway has a pool of public address that it is free to assign to a local host when it makes a request to access the Internet 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.  IPv4 Addresses (4 of 4) Figure 3-12 PAT (Port Address Translation) 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.  IPv6 Addresses (1 of 2) An IPv6 address has 128 bits written as eight blocks of hexadecimal numbers separated by colons Ex: 2001:0000:0B80:0000:0000:00D3:9C5A:00CC Each block is 16 bits Leading zeros in a four-character hex block can be eliminated If blocks contain all zeroes, they can be written as double colons (::), only one set of double colons is used in an IP address Therefore, above example can be written two ways: 2001::B80:0000:0000:D3:9C5A:CC 2001:0000:B80::D3:9C5A:CC (this is the preferred method because it contains the fewest zeroes) 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.  IPv6 Addresses (2 of 2) IPv6 terminology: A link (sometimes called local link) is any LAN bounded by routers Neighbors are two or more nodes on the same link Dual stacked is when a network is configured to use both IPv4 and IPv6 Tunneling is a method used by IPv6 to transport IPv6 packets through or over an IPv4 network Interface ID is the last 64 bits or four blocks of an IPv6 address that identify the interface 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.  Types of IPv6 Addresses (1 of 4) Unicast address - specifies a single node on a network Global address can be routed on the Internet Link local address can be used for communicating with nodes in the same link Loopback address can be used to test that an interface and supporting protocol stack are functioning properly Multicast address – delivers packets to all nodes on a network Anycast address - can identify multiple destinations, with packets delivered to the closest destination 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. Types of IPv6 Addresses (2 of 4) Figure 3-16 Three types of IPv6 addresses 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. Types of IPv6 Addresses (3 of 4) Figure 3-18 The ipconfig command shows IPv4 and IPv6 addresses assigned to this 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.  Types of IPv6 Addresses (4 of 4) IPv6 autoconfiguration IPv6 addressing is designed so that a computer can autoconfigure its own link local IP address This process is called SLAAC (stateless address autoconfiguration) Step 1 - The computer creates its IPv6 address It uses FE80::/64 as the first 64 bits (called prefix) The last 64 bits are generated from the network adapter’s MAC address Step 2 - The computer checks to make sure its IP address is unique on the network Step 3 - The computer asks if a router on the network can provide configuration information This message is called an RS (router solicitation) message 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.  Ports and Sockets (1 of 2) A port is a number assigned to a process that can receive data Port numbers ensure data is transmitted to the correct process among multiple processes running on a single device A socket consists of host’s IP address and the port number of an application running on the host A colon separates the two values Example - 10.43.3.87:23 Port numbers are divided into three types: Well-known ports - 0 to 1023 Registered ports - 1024 to 49151 Dynamic and private ports - 49152 to 65535 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.  Ports and Sockets (2 of 2) Figure 3-19 A virtual connection for the Telnet 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.  Domain Names and DNS (1 of 2) Character-based names are easier to remember than numeric IP addresses A URL (uniform resource locator) is an addressing scheme that identifies where to find a particular resource on a network Last part of an FQDN is called the top-level domain (TLD) Domain names must be registered with an Internet naming authority that works on behalf of ICANN ICANN restricts what type of hosts can be associated with.arpa,.mil,.int,.edu, and.gov Name resolution is the process of discovering the IP address of a host when you know the FQDN 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.  Domain Names and DNS (2 of 2) DNS is an Application layer client-server system of computers and databases made up of these elements: Namespace - the entire collection of computer names and their associated IP addresses stored in databases on DNS name servers around the globe Name servers - hold databases, which are organized in a hierarchical structure Resolvers - a DNS client that requests information from DNS name servers 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.  Namespace Databases Each organization that provides host services is responsible for providing and maintaining its own DNS authoritative servers for public access An authoritative name server is the authority on computer names and their IP addresses for computers in their domains The domains that the organization is responsible for managing are called a DNS zone 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.  Name Servers (1 of 4) Four common types of DNS servers: Primary DNS server – the authoritative name server for the organization Holds the authoritative DNS database for the organization’s zones Secondary DNS server – backup authoritative name server for the organization Caching DNS server – accesses the public DNS data and caches the DNS information it collects Forwarding DNS server – receives queries from local clients but doesn’t work to resolve the queries Any of these DNS server types can co-exist on the same machine DNS name servers are organized in a hierarchical structure At the root level, 13 clusters of root DNS servers hold information used to locate top-level domain (TLD) servers 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.  Name Servers (2 of 4) Figure 3-21 Hierarchy of name servers 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.  Name Servers (3 of 4) Figure 3-22 Queries for name resolution of www.mdc.edu 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.  Name Servers (4 of 4) Ways the resolution process can get more complex: A caching server typically is not the same machine as the authoritative server The caching server exists only to resolve names for its own local clients Name servers within a company might not have access to root servers A TLD name server might be aware of an intermediate name server rather than the authoritative name server Two types of DNS requests: Recursive lookup – a query that demands a resolution or the answer “It can’t be found” Iterative lookup – a query where the local server issues queries to other servers Other servers only provide information if they have it Do not demand a resolution 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.  Resource Records in a DNS Database Several types of records, called resource records are kept in a DNS database: SOA (start of authority) record – gives information about the zone A (address) record – stores the name-to-address mapping for a host AAAA (address) record – holds the name-to-address mapping, the IP address is an IPv6 type IP address CNAME (canonical Name) record – holds alternative names for a host PTR (pointer) record – used for reverse lookups NS (name Server) record – indicates the authoritative name server for a domain MX (mail exchanger) record – identifies a mail server and is used for email traffic SRV (service) record – identifies the hostname and port of a computer that hosts a specific network services besides email TXT (text) record – holds any type of free-form text 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.  DNS Server Software BIND (Berkeley Internet Name Domain) is the most popular DNS server software Open source - the term for software whose code is publicly available for use and modification Microsoft DNS Server is a built-in DNS service in the Windows Server OS Windows Server is capable of split-brain or split-horizon deployment, which is used to handle internal clients and external clients 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 Address Problems Figure 3-24 Event Viewer provided the diagnosis of a printer problem and recommended steps to fix the problem 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 Tools (1 of 8) Command-line tools are a great resource to troubleshoot network problems ping (Packet Internet Groper) utility is used to verify that TCP/IP is: Installed Bound to the NIC Configured correctly Communicating with the network The ping utility sends out a signal called an echo request to another device (request for a response) The other computer responds in the form of an echo reply ICMP (Internet Control Message Protocol) is the protocol used by the echo request/reply to carry error messages and information about the 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.  Troubleshooting Tools (2 of 8) IPv6 networks use a version of ICMP called ICMPv6 ping6 – on Linux computers running IPv6, use ping6 to verify whether an IPv6 host is available ping -6 – on Windows computers, use ping with the -6 switch to verify connectivity on IPv6 networks For the ping6 and ping -6 commands to work over the Internet, you must have access to the IPv6 Internet 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 Tools (3 of 8) The ipconfig command shows current TCP/IP addressing and domain name information on a Windows computer Use ipconfig/all to see a more complete summary of TCP/IP addressing information 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 Tools (4 of 8) Figure 3-29 ipconfig /all gives more information than ipconfig by itself 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 Tools (5 of 8) Use the ip utility to view and manage TCP/IP settings The ip utility is only available on UNIX and Linux systems Any ip commands that change the state of a link require elevated privileges This is accomplished by logging in as the root user or by temporarily elevating the current user's privileges with the sudo (superuser do) command ifconfig is a similar utility used to view and manage TCP/IP settings If your Linux or UNIX system provides a GUI Open a shell prompt, then type ifconfig 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 Tools (6 of 8) Figure 3-32 Use hostname to view or change a device’s host name 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 Tools (7 of 8) The nslookup (name space lookup) utility allows you to query the DNS database from any computer on a network To find the host name of a device by specifying its IP address, or vice versa It is useful for verifying a host is configured correctly or for troubleshooting DNS resolution problems Reverse DNS lookup - to find the host name of a device whose IP address you know nslookup 69.23.208.74 The nslookup utility is available in two modes: Interactive - to test multiple DNS servers at one time Noninteractive - test a single DNS server You can change DNS servers from within interactive mode with the server subcommand and specifying the IP address of the new DNS server To exit nslookup’s interactive mode, enter exit 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 Tools (8 of 8) The dig (domain information groper) utility is available on Linux and macOS Provides more detailed information than nslookup and uses more reliable sources of information to output its results Use dig to query DNS nameservers for information about host addresses and other DNS records An IP scanner can be used to gather information about all devices connected to 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.  Common Network Issues (1 of 2) Incorrect time Check a domain computer’s time source from a Command Prompt window by entering w32tm /query /source DHCP Issues If you are getting DHCP errors or if multiple clients are having trouble connecting to the network, try the following: Check the settings on your DHCP server Make sure the DHCP scope is large enough to account for the number of clients the network must support Consider implementing a shorter lease time on larger networks 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.  Common Network Issues (2 of 2) Network Connection Configuration Issues Common configuration errors: Incorrect IP address Duplicate IP address Incorrect subnet mask Incorrect gateway Incorrect DNS or DNS issues When a computer is struggling to establish a network connection Check its TCP/IP configuration settings If the computer is not obtaining an IP address and related information from a DHCP server Static settings might be using the wrong information Try switching to DHCP 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. Describe the functions of core TCP/IP protocols 2. Identify how each protocol’s information is formatted in a TCP/IP message 3. Secure network connections using encryption protocols 4. Configure remote access connections between devices 5. Employ various TCP/IP utilities for network discovery and troubleshooting 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.  TCP/IP Core Protocols (1 of 3) TCP/IP is a suite of protocols including: TCP, IP (IPv4 and IPv6), UDP, ARP, and many others TCP/IP protocols add a header to data inherited from the layer above it Layers 7, 6, and 5 - Data and instructions, known as payload, are generated by applications running on source host Layer 4 – A Transport Layer protocol, usually TCP or UDP, adds a header to the payload Includes a port number to identify the receiving app Layer 3 - Network layer adds it own header and becomes a packet Layer 2 - packet is passed to Data Link layer on NIC, which encapsulates data with its own header and trailer, creating a frame Layer 1 - Physical layer on the NIC receives the frame and places the transmission on the 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. TCP/IP Core Protocols (2 of 3) Figure 4-1 Each layer adds its own data and addresses its transmission to the corresponding layer in the destination device 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.  TCP/IP Core Protocols (3 of 3) The receiving host decapsulates the message at each layer in reverse order and presents payload to the receiving applications In transit, transmissions might pass through a number of connectivity devices Connectivity devices are specialized devices that allow two or more networks or multiple parts of one network to connect and exchange data Known by the highest OSI layer they read and process 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.  TCP (Transmission Control Protocol) (1 of 4) TCP operates in the transport layer of OSI model Three characteristics of TCP: Connection-oriented - TCP ensures that a connection or session is established by using a three-step process called a three-way handshake Sequencing and checksums - TCP sends a character string called a checksum that is checked by the destination host along with a sequence number for each segment Flow control - gauges rate of transmission based on how quickly recipient can accept data 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. TCP (Transmission Control Protocol) (2 of 4) Figure 4-3 A TCP segment 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.  TCP (Transmission Control Protocol) (3 of 4) The TCP three-way handshake establishes a session before TCP transmits actual data Three transmissions are sent before data transmission: Step 1 – a request for a connection (SYN) Step 2 – a response to the request (SYN/ACK) Step 3 – a connection is established (ACK) After the three initial messages, the payload or data is sent Sequence numbers will be increased by the number of bits included in each received segment Confirms the correct length of message was received 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. TCP (Transmission Control Protocol) (4 of 4) Figure 4-4 The three-way handshake process establishes a TCP session 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.  UDP (User Datagram Protocol) UDP is an unreliable, connectionless protocol No three-way handshake is performed UDP does not guarantee delivery of data UDP provides no error checking, sequencing, or flow control This makes UDP more efficient than TCP Useful for live audio or video transmissions over the Internet Also more efficient for carrying messages that fit within one data packet A UDP header contains only four fields: Source port, Destination port, Length, and Checksum Use of Checksum field in UDP is optional in IPv4, but required in IPv6 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.  IP (Internet Protocol) (1 of 3) IP operates at the network layer of the OSI model It specifies where data should be delivered Identifies the data’s source and destination IP addresses IP enables TCP/IP to internetwork To traverse more than one LAN segment and more than one type of network through a router IP is an unreliable, connectionless protocol That means that IP does not guarantee delivery of data and no session is established before data is transmitted IP depends on TCP to ensure messages are put back together in the right order and to ensure each message reaches the correct application on the receiving host 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.  IP (Internet Protocol) (2 of 3) Figure 4-7 An IPv4 packet 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.  IP (Internet Protocol) (3 of 3) IPv6 Packets IPv6 uses a different packet format than IPv4 IPv6 can accommodate the much longer IPv6 addresses There is no Fragment offset field IPv6 hosts adjust their packet sizes to fit the requirements of the network before sending IPv6 messages 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.  ICMP (Internet Control Message Protocol) ICMP is a core network layer protocol that reports on the success or failure of data delivery ICMP can indicate the following: When part of a network is congested When data fails to reach its destination When data has been discarded because the allotted TTL has expired ICMP announces transmission failures to the sender but does not correct errors it detects It provides critical information for troubleshooting network problems ICMPv6 on IPv6 networks performs the functions of ICMP and ARP on IPv4 networks 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.  ARP (Address Resolution Protocol) on IPv4 Networks (1 of 2) ARP works in conjunction with IPv4 to discover the MAC address of a host or node on the local network And to maintain a database that maps IP addresses to MAC addresses on the local network ARP is a Layer 2 protocol that uses IP in Layer 3 and relies on broadcasting Operates only within its local network ARP table is the database of IP-to-MAC address mappings An ARP table can contain two types of entries: Dynamic - created when a client makes an ARP request that could not be satisfied by data already in the ARP table Static - those someone entered manually using the ARP utility (arp command) To view a Window’s workstation’s ARP table, enter the command: arp -a 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. ARP (Address Resolution Protocol) on IPv4 Networks (2 of 2) Figure 4-13 The arp –a command lists devices on the 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.  NDP (Neighbor Discovery Protocol) IPv6 devices learn about other devices on their networks through a process called neighbor discovery NDP (Neighbor Discovery Protocol) information carried in ICMPv6 messages automatically detects neighboring devices and automatically adjusts when nodes fail or are removed NDP offers several ICMPv6 message types: RA (router advertisement) RS (router solicitation) Redirect NS (neighbor solicitation) NA (neighbor advertisement) 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.  Ethernet (1 of 2) Ethernet is the most important data link layer standard It is capable of running on a variety of network media Ethernet offers excellent throughput at a reasonable cost It is the most popular network technology used on modern LANs Ethernet II is the current standard Ethernet adds both a header and a trailer to the payload This creates a frame around the payload The header and FCS make up the 18-byte “frame” around the data The data portion of an Ethernet frame may contain from 46 to 1500 bytes MTU (maximum transmission unit) is the largest size that routers in a message’s path will allow at the Network 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.  Ethernet (2 of 2) Figure 4-14 Ethernet II frame 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.  Encryption Protocols Encryption protocols use a mathematical code, called a cipher, to scramble data into a format that can be read only by reversing the cipher The purpose of encryption is to keep information private Encryption methods are primarily evaluated by three benchmarks: Confidentiality Integrity Availability The principles above form the standard security model called the CIA triad 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.  Key Encryption (1 of 2) A key is a random string of characters woven into original data’s bits It generates unique data block called ciphertext The key is created according to a specific set of rules (algorithms) Key encryption can be separated into two categories: Private key encryption Public key encryption 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.  Key Encryption (2 of 2) Figure 4-15 Private key encryption uses only one key, which must be securely communicated between sender and receiver, while public key encryption relies on a second, public key that can safely be obtained by anyone 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.  IPsec (Internet Protocol Security) IPsec is an encryption protocol suite that defines rules for encryption, authentication, and key management for TCP/IP transmissions IPsec creates secure connections in five steps: 1. IPsec initiation 2. Key management 3. Security negotiations 4. Data transfer 5. Termination Operates in two modes: Transport mode Tunnel mode 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.  SSL (Secure Sockets Layer) and TLS (Transport Layer Security) Both SSL and TLS are methods of encrypting TCP/IP transmissions Both protocols work side by side and are widely known as SSL/TLS or TLS/SSL When a client and server establish a SSL/TLS connection, they establish a unique session which is an association between client and server The session is defined by an agreement on a specific set of encryption techniques A session is created by an SSL handshake protocol The handshake protocol allows client and server to authenticate This handshake is similar to a TCP three-way handshake 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.  Remote Access Protocols Remote access is a service that allows a client to connect with and log on to a server, LAN, or WAN in a different geographical location Remote access requires a type of RAS (remote access server) There are two types of remote access servers: Dedicated devices Software running on a server Types of remote access include: Remote file access Terminal emulation, also called remote virtual computing VPN (virtual private 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.  Remote File Access FTP (File Transfer Protocol) provides remote file access Three related technologies include the following: FTPS (FTP Secure or FTP over SSL) offers an added layer of protection for FTP using SSL/TLS SFTP (Secure FTP) is a file-transfer version SSH that include encryption and authentication for transferring files TFTP (Trivial FTP) is a simple protocol similar to FTP except that it includes no authentication or security for transferring files 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.  Terminal Emulation (1 of 4) A terminal emulator is software that allows a user on one computer (client) to control another computer (host or server) Examples of command-line software: Telnet and SSH Examples of GUI-based software: Remote Desktop for Windows join.me VNC Team Viewer 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.  Terminal Emulation (2 of 4) Telnet is a terminal emulation utility that allows an administrator or other user to control a computer remotely It provides little security for establishing a connection (poor authentication) It provides no security for transmitting data (no encryption) SSH (Secure Shell) is a collection of protocols that provides for secure authentication and encryption Guards against a number of security threats Unauthorized access to a host IP spoofing Interception of data in transit DNS spoofing Secure connection requires SSH running on both client and server Allows for password authentication using public and private key generation 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.  Terminal Emulation (3 of 4) Figure 4-20 On a Windows computer, use an app like PuTTY to create an SSH connection to another 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.  Terminal Emulation (4 of 4) RDP (Remote Desktop Protocol) is a Microsoft proprietary protocol used to connect to and control a remote computer VNC (Virtual Network Computing) uses the cross-platform protocol RFB (remote frame buffer) to remotely control a workstation or server VNC is open source so many companies have developed their own software that can: Run OSes on client computers Remotely access computers, tablets, and smartphones Remotely control media equipment and surveillance systems Out-of-band management relies on a dedicated connection between the network administrator’s computer and each network device A remote management card is attached to the network device’s console port A single device, such as a console server or console router, provides centralized management of all linked devices 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.  VPNs (Virtual Private Networks) (1 of 4) A VPN is a network connection encrypted from end to end that creates a private connection to a remote network A VPN is sometimes referred to as a tunnel VPNs can be classified according to three models: Site-to-site VPN Client-to-site VPN Also called host-to-site VPN or remote-access VPN Host-to-host VPN 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.  VPNs (Virtual Private Networks) (2 of 4) To ensure VPNs can carry all types of data securely, special VPN protocols encapsulate higher-layer protocols in a process known as tunneling Many VPN tunneling protocols operate at the data link layer to encapsulate the VPN frame into a network layer packet Some VPN tunneling protocols work at Layer 3, which enables additional features and