CompTIA Network+ N10-009 Jason Dion Study Note Flashcards

Network Fundamentals - Network Components - Clients

Devices that users use to access the network (e.g., workstations, laptops, tablets)

Network Fundamentals - Network Components - Servers

Provide resources to the network (e.g., email servers, file servers)

Network Fundamentals - Network Components - Hubs

Older technology connecting devices but not commonly used due to limitations

Network Fundamentals - Network Components - Switches

Smarter hubs that ensure security and efficient bandwidth utilization

Network Fundamentals - Network Components - Wireless Access Points (WAPs)

Enable wireless devices to connect to a wired network using radio frequency waves

Network Fundamentals - Network Components - Routers

Connect different networks, make intelligent forwarding decisions based on IP addresses

Network Fundamentals - Network Components - Firewalls

Security barrier between internal network and the internet, monitor and control traffic

Network Fundamentals - Network Components - Load Balancers

Distribute network/application traffic across servers, preventing bottlenecks

Network Fundamentals - Network Components - Proxy Servers

Act as intermediaries between user devices and the internet, enhancing security and privacy

Network Fundamentals - Network Components - Intrusion Detection Systems (IDS)

Detect unauthorized access or anomalies

Network Fundamentals - Network Components - Intrusion Prevention Systems (IPS)

Detect and take action to prevent intrusion

Network Fundamentals - Network Components - Controllers

Manage flow control in software-defined networking (SDN), offering flexibility and efficiency

Network Fundamentals - Network Components - Network-attached Storage (NAS) Devices

Dedicated file storage systems providing data access to authorized clients

Network Fundamentals - Network Components - Storage Area Networks (SANs)

High-speed networks for consolidated block-level data storage, enhancing accessibility

Network Fundamentals - Network Components - Media

Physical materials for data transmission (e.g., copper cables, fiber optic cables)

Network Fundamentals - Network Components - Wide Area Network (WAN) Links

Connect networks over large areas (e.g., between cities), essential for global connectivity

Network Fundamentals - Network Resources - Client/Server Model

Utilizes a dedicated server for centralized access to files, scanners, printers, and resources; Easy administration and backup due to a central server

Network Fundamentals - Network Resources - Client/Server Model Benefits

Centralized administration; Easier management; Better scalability

Network Fundamentals - Network Resources - Client/Server Model Drawbacks

Higher cost; Requires dedicated hardware and specialized skillset

Network Fundamentals - Network Resources - Peer-to-Peer Model

Direct sharing of resources among peers (laptops, desktops); Difficult administration and backup due to dispersed files on different machines

Network Fundamentals - Network Resources - Peer-to-Peer Model Drawbacks

Redundancy; Complex management; Scalability issues

Network Fundamentals - Network Geography - Personal Area Network (PAN)

Smallest network type; Covers about 10 feet or less; Examples are Bluetooth and USB; Connection within arm's reach

Network Fundamentals - Network Geography - Local Area Network (LAN)

Common in office buildings; Limited distance (Up to 100 meters, CAT 5 cabling); Can use WiFi (IEEE 802.11) or Ethernet (IEEE 802.3); Examples include Office, school, and home

Network Fundamentals - Network Geography - Campus Area Network (CAN)

Building-centric LAN; Spans numerous buildings in an area; Covers several miles; Examples are College campuses, business parks, military bases

Network Fundamentals - Network Geography - Metropolitan Area Network (MAN)

Connects locations across the entire city; Larger than CAN (Up to 25 miles); Examples are City departments, multiple campuses in a city

Network Fundamentals - Network Geography - Wide Area Network (WAN)

Connects geographically disparate internal networks; Large geographic coverage (Across states, countries, or globally); Can consist of lease lines or VPNs; Examples are Internet, private connections between offices across the country

Network Fundamentals - Network Geography - Important Standards - PAN

Bluetooth, USB (considered personal area networks)

Network Fundamentals - Network Geography - Important Standards - LAN

IEEE 802.3 (Ethernet)

Network Fundamentals - Network Geography - Important Standards - CAN

connects multiple LANs, forming a larger network

Network Fundamentals - Network Geography - Important Standards - MAN

spans an entire city, connecting different locations

Network Fundamentals - Network Geography - Important Standards - WAN

encompasses large geographic areas, connecting internal networks globally

Network Fundamentals - Wired Network Topology - Network Topology

Refers to the arrangement of elements in a computer network; Includes links, nodes, clients, and servers

Network Fundamentals - Wired Network Topology - Diagram Types - Physical Topology

Describes physical cabling and device connections; Represents real-world layout using floorplans

Network Fundamentals - Wired Network Topology - Diagram Types - Logical Topology

Describes how data flows in the network; Focuses on the logical connection rather than physical placement

Network Fundamentals - Wired Network Topology - Point-to-Point Topology

Direct connection between two devices; Simple, reliable for small-scale connections; Not scalable; Used in WAN connections for remote offices

Network Fundamentals - Wired Network Topology - Ring Topology

Circular data path with each device connected to two others; Unidirectional flow prevents collisions; Creates a single point of failure situation unless there are redundant connections for failover; Common in FDDI (Fiber Distributed Data Interface) for long-distance fiber optic networks

Network Fundamentals - Wired Network Topology - Bus Topology

All devices connected to a central cable (bus); Data accessible to all, but only intended recipient processes it; Easy to install; If the main cable fails, the network won't work; The more devices connected to the network, the more collisions will occur; Older technology, not common in modern networks

Network Fundamentals - Wired Network Topology - Star Topology

Each node connected to a central point (network switch); Robust, but network depends on the central point's functionality; If the central point fails, the entire network fails; Common in home networks

Network Fundamentals - Wired Network Topology - Hub-and-Spoke Topology

Variation of star topology with a central hub connected to multiple spokes; Nodes transmit data to the hub before reaching the final destination; Used in airline and telecommunications networks; Less expensive for larger networks

Network Fundamentals - Wired Network Topology - Mesh Topology

Point-to-point connections between every device for redundancy; Two types: Full mesh - every node connected to every other; Partial mesh - some nodes fully interconnected, others connected to one or two devices; Provides robustness and redundancy but can be complex and costly

Network Fundamentals - Wired Network Topology - Mesh Topology Formula - Full mesh connections formula

n (n-1)/2; n is the number of nodes

Network Fundamentals - Wireless Network Topology - Infrastructure Mode

Centralized wireless network with a wireless access point; Similar to a star topology in a physical network; Common in homes; Connects to an outside provider through a cable or fiber modem; Supports wireless security controls

Network Fundamentals - Wireless Network Topology - Ad Hoc Mode

Decentralized wireless network; Operates like a peer-to-peer network; No routers or access points; Devices connect directly; Dynamic routing decisions made on the fly; Allows for dynamic joining and leaving of devices; Resembling old-school chat rooms

Network Fundamentals - Wireless Network Topology - Wireless Mesh

Unique interconnection of different nodes, devices, and radios; Creates a mesh topology for expansion and redundancy; Combines various technologies for connectivity (Bluetooth, WiFi, microwave, cellular, satellite); Enables large-scale network access in harsh environments; Uses different radio frequencies to establish reliable connections

Network Fundamentals - Datacenter Topology - Datacenter

Any facility composed of networked computers and storage that businesses and other organizations use to organize, process, store, and disseminate large amounts of data

Network Fundamentals - Datacenter Topology - Three-Tiered Hierarchy - Core Layer

Houses high-performance routers, merging geographically separated networks; Backbone of the network

Network Fundamentals - Datacenter Topology - Three-Tiered Hierarchy - Distribution/Aggregation Layer

Provides boundary definition through access lists and filters; Defines policies for the network at large; Uses layer 3 switches for routing between subnets; Ensure the packets are properly routed between different subnets and VLANs

Network Fundamentals - Datacenter Topology - Three-Tiered Hierarchy - Access/Edge Layer

Connects endpoint devices using regular switches; Used to ensure the packets are converted to frames and delivered to the correct end point devices

Network Fundamentals - Datacenter Topology - Collapsed Core

Network architecture where the core and distribution layers are merged into a single layer; Creates a two tiered core; Simplified architecture for medium to small datacenters; May not be suitable for larger and more complex networks

Network Fundamentals - Datacenter Topology - Spine and Leaf Architecture

An alternative type of network architecture that is used specifically within datacenters; Focuses on communication within datacenters, particularly server farms; Consists of 2 switching layers: Leaf and Spine

Network Fundamentals - Datacenter Topology - Spine and Leaf Architecture - Leaf

Consists of all the access switches that will aggregate traffic from the different servers and then connect directly into the spine layer

Network Fundamentals - Datacenter Topology - Spine and Leaf Architecture - Spine

Contains switches that interconnect all the leaf layer switches into a full-mesh topology

Network Fundamentals - Datacenter Topology - Traffic Flows - North-South Traffic

Traffic that enters (Southbound traffic) or leaves (Northbound traffic) data center from a system outside

Network Fundamentals - Datacenter Topology - Traffic Flows - East-West Traffic

Data flow within a datacenter; Example: In a spine and leaf architecture, all data flow between servers is considered east-west traffic; Prevalent with SDN, virtualization, and converged networks

OSI Model - Introduction - Open Systems Interconnect Model (OSI)

Developed in 1977 by the International Organization for Standardization; OSI is a reference model; Used to categorize the functions of a network; Useful for troubleshooting

OSI Model - Layers

Physical - Layer 1; Data Link - Layer 2; Network - Layer 3; Transport - Layer 4; Session - Layer 5; Presentation - Layer 6; Application - Layer 7

OSI Model - Names of data as it flows through the OSI model

Bits - Layer 1; Frames - Layer 2; Packets - Layer 3; Segments - Layer 4; Data - Layer 5; Data - Layer 6; Data - Layer 7

OSI Model - Layer 1 (Physical) - Physical Layer Overview (Layer 1)

First layer of the OSI model where transmission of bits across the network occurs and includes physical and electrical network characteristics; Data type occurs as bits - Binary bits represented as a series of 1s and 0s

OSI Model - Layer 1 (Physical) - Transition Modulation

Switching between levels to represent 1 or 0; Copper Wire (Cat5/Cat6) - Uses voltage (0V for 0, +5V/-5V for 1); Fiber Optic Cable - Uses light (on for 1, off for 0)

OSI Model - Layer 1 (Physical) - Connector Standards

RJ-45 Connector - Used in CAT5/CAT6 cables; Wiring Standards: TIA/EIA-568A; TIA/EIA-568B

OSI Model - Layer 1 (Physical) - Cables

Crossover cables - TIA/EIA-568A on one end, and TIA/EIA-568B on the other end; Straight-through cables - TIA/EIA-568B on both ends

OSI Model - Layer 1 (Physical) - Physical Topology

Different physical network layouts: Bus, Ring, Star, Hub-and-Spoke, Full Mesh, Partial Mesh; Based on how cables are physically connected

OSI Model - Layer 1 (Physical) - Synchronization - Asynchronous Communication

Start and stop bits for out-of-sync data transmission

OSI Model - Layer 1 (Physical) - Synchronization - Synchronous Communication

Real-time communication using a common time source

OSI Model - Layer 1 (Physical) - Bandwidth Utilization - Broadband

Divides bandwidth into separate channels (e.g., cable TV)

OSI Model - Layer 1 (Physical) - Bandwidth Utilization - Baseband

Uses all frequency of the cable all the time (e.g., telephone)

OSI Model - Layer 1 (Physical) - Multiplexing

Involves taking some limited amount of resource and using it more efficiently; Allows multiple people to use a baseband connection at the same time

OSI Model - Layer 1 (Physical) - Multiplexing Types - Time Division Multiplexing (TDM)

Allocates dedicated time slots

OSI Model - Layer 1 (Physical) - Multiplexing Types - Statistical Time Division Multiplexing (StatTDM)

Dynamically allocates time slots based on when people need it

OSI Model - Layer 1 (Physical) - Multiplexing Types - Frequency Division Multiplexing (FDM)

Divides the medium into channels

OSI Model - Layer 1 (Physical) - Layer 1 Devices - Cables - media

Fiber optic; Ethernet; Coaxial

OSI Model - Layer 1 (Physical) - Layer 1 Devices - Wireless Media

Bluetooth; Wi-Fi; Near field communication

OSI Model - Layer 1 (Physical) - Layer 1 Devices - Infrastructure Devices

Hubs; Access points; Media converters

OSI Model - Layer 1 (Physical) - Layer 1 Device Characteristics

Simply repeat whatever they receive; No logic or decision-making at Layer 1

OSI Model - Layer 2 (Data Link Layer) - Data Link Layer (Layer 2)

Responsible for packaging bits from Layer 1 into frames and transmitting them across the network; Performs error detection and correction, identifies devices using MAC addresses, and provides flow control

OSI Model - Layer 2 (Data Link Layer) - MAC Address (Media Access Control Address)

A means for identifying a device physically and allowing it to operate on a logical topology; A unique 48-bit physical addressing system is assigned to every network interface card (NIC) produced; Written in hexadecimal numbers; First 24 bits - identify the manufacturer; Remaining 24 bits - identify the specific device; Crucial for logical topology - identifying devices on the network

OSI Model - Layer 2 (Data Link Layer) - Logical Link Control (LLC)

Provides connection services and acknowledges message receipt, ensuring controlled data flow; Most basic form of flow control; Limits data sent by a sender and prevents receiver overwhelm; Uses a checksum to detect corrupted data frames

OSI Model - Layer 2 (Data Link Layer) - Synchronization Methods at Layer 2 - Isochronous Mode

Common reference clock; Time slots for transmissions; Less overhead

OSI Model - Layer 2 (Data Link Layer) - Synchronization Methods at Layer 2 - Synchronous Method

Devices use the same clock, with beginning and ending frames, and control characters for synchronization

OSI Model - Layer 2 (Data Link Layer) - Synchronization Methods at Layer 2 - Asynchronous

Devices reference own clock cycles; No strict control over communication timing

OSI Model - Layer 2 (Data Link Layer) - Layer 2 Devices

Network Interface Cards (NICs); Bridges; Switches

OSI Model - Layer 2 (Data Link Layer) - Switch Operation

Switches use CAM tables with MAC addresses to identify physical ports connected to devices; Enables selective data transmission to specific areas in the network.

OSI Model - Layer 3 (Network Layer) - Network Layer (Layer 3)

Concerned with routing and forwarding traffic using logical addresses

OSI Model - Layer 3 (Network Layer) - Logical Addressing

IP variants - common logical addressing schemes: IPv4 - written in dotted octet notation which are four sets of numbers separated by dots (e.g., 172.16.254.1); IPv6; Other protocols - these were replaced by IP (Internet Protocol): AppleTalk; IPX (Internetwork Packet Exchange)

OSI Model - Layer 3 (Network Layer) - Switching/Routing Methods - Packet Switching (Routing)

Data is divided into packets and then forwarded; Most commonly used method

OSI Model - Layer 3 (Network Layer) - Switching/Routing Methods - Circuit Switching

A dedicated communication link is established between two devices

OSI Model - Layer 3 (Network Layer) - Switching/Routing Methods - Message Switching

Data is divided into messages which may be stored and then forwarded

OSI Model - Layer 3 (Network Layer) - Route Discovery and Selection

Routers maintain routing tables for determining the best path; Dynamic protocols (e.g., RIP, OSPF) enable routers to share and update route information; Routing protocols help decide how data is going to flow across the network and how the routers are going to communicate that information

OSI Model - Layer 3 (Network Layer) - Connection Services at Layer 3

Augments Layer 2 services; Involves flow control: Prevents sender from overwhelming the receiver; Packet reordering: Ensures data packets arrive and are reassembled in the correct order

OSI Model - Layer 3 (Network Layer) - Internet Control Message Protocol (ICMP)

Used for sending error messages and operational information to an IP destination

OSI Model - Layer 3 (Network Layer) - ICMP Utilities - PING

Most commonly used ICMP; Helps troubleshoot network issues by testing connectivity and response times

OSI Model - Layer 3 (Network Layer) - ICMP Utilities - Traceroute

Traces the route of a packet through the network

OSI Model - Layer 3 (Network Layer) - Devices and Protocols - Routers

Routers

OSI Model - Layer 3 (Network Layer) - Devices and Protocols - Multi-layer switches

Combines Layer 2 switch and Layer 3 router features; A switch is always a Layer 2 device, unless specifically mentioned that it is a multi-layer switch, then it is considered as a Layer 3 device

OSI Model - Layer 3 (Network Layer) - Devices and Protocols - Layer 3 protocols

IPv4; IPv6; ICMP

OSI Model - Layer 4 (Transport Layer) - Transport Layer (Layer 4)

Dividing line between the upper layers and the lower layers of the OSI model; Upper Layers: Transport, Session, Presentation, Application

OSI Model - Layer 4 (Transport Layer) - Data Type in Transport Layer

Segments

OSI Model - Layer 4 (Transport Layer) - Protocols in Layer 4 - TCP (Transmission Control Protocol)

Connection-oriented protocol that is a reliable way to transport segments across the network; With acknowledgement; Uses Three-Way Handshake: SYN - synchronization, SYN-ACK - synchronization - acknowledgement, ACK - acknowledgement; Windowing for flow control; Used for all network data that needs to be assured to get to its final destination

OSI Model - Layer 4 (Transport Layer) - Protocols in Layer 4 - UDP (User Datagram Protocol)

A connectionless protocol that is an unreliable way to transport segments (datagram); Used for audio and visual streaming; No three-way handshake and less overhead; No acknowledgment or retransmission

OSI Model - Layer 4 (Transport Layer) - TCP vs. UDP - TCP

Reliable; Uses Three-way Handshake; Connection-oriented; Segment retransmission and flow control through windowing; Sequencing; Acknowledgment of segments