WIP - Network+

CompTIA Network+

CompTIA Network+

A vendor neutral networking certification that validates essential knowledge and skills in designing, configuring, managing, and troubleshooting wired and wireless devices.

Network Documentation

The process of recording and organizing information about a network, including its configuration, devices, and connections.

Network Standards

Guidelines and protocols that define how network devices communicate and interact with each other.

Network Security

Measures and practices implemented to protect a network from unauthorized access, data breaches, and other security threats.

Cloud Technologies

Technologies and services that enable the storage, management, and access of data and applications over the internet.

Virtualization

The process of creating virtual instances or environments of computer resources, such as servers, operating systems, or networks.

Networking Fundamentals

The basic principles, concepts, and components of computer networks.

Network Implementations

The process of configuring and setting up network devices and infrastructure to create a functional network.

Network Operations

The ongoing management and maintenance of a network, including monitoring, troubleshooting, and optimizing its performance.

Network Troubleshooting

The process of identifying and resolving issues or problems in a network to ensure its proper functioning.

Network Traffic

The data and information that flows through a network, such as file sharing, video chatting, web surfing, and email communication.

Client

A device used by an end-user to access and connect to a network, such as a workstation, laptop, tablet, smartphone, or television.

Server

A device that provides resources and services to other devices on a network, such as email, web, file, chat, or print servers.

Hub

An older technology used to connect networked devices, but leads to increased network errors and broadcasts information to all other ports.

Wireless Access Point (WAP)

A device that allows wireless devices to connect to a wired network and acts as a wireless hub.

Switch

A device that connects networked devices and forwards traffic based on the device's MAC address, providing more security and efficient bandwidth usage.

Router

A device that connects different networks together and intelligently forwards traffic based on logical addresses, such as IP addresses.

Media

The physical medium used to connect devices or ports, such as copper cable, fiber optic cable, or wireless radio frequency waves.

Wide Area Network (WAN) Link

A physical connection that connects networks together, such as leased lines, DSL, cable, fiber optic, satellite, or cellular connections.

Client/Server Model

A network model where a dedicated server provides access to resources, such as files, printers, and scanners, to client devices.

Peer-to-Peer Model

A network model where peers (PCs) directly share resources, such as files and printers, with each other without the need for dedicated servers.

Personal Area Network (PAN)

The smallest type of wired or wireless network that covers a limited area, such as connecting a cellphone to a car or a USB hard drive to a laptop.

Local Area Network (LAN)

A network that connects components within a limited distance, such as a building or office, using Ethernet or WiFi networks.

Campus Area Network (CAN)

A network that connects building-centric LANs across a university, industrial park, or business park, covering many square miles and buildings.

Metropolitan Area Network (MAN)

A network that connects scattered locations across a city, larger than a CAN but smaller than a WAN, covering up to a 25-mile radius.

Wide Area Network (WAN)

A network that connects geographically disparate internal networks, covering distances around the country or world, using leased lines or VPNs.

Bus Topology

A network topology where devices are connected to a cable running through the area, forming a single collision domain.

Ring Topology

A network topology where devices are connected in a circular loop, with data traveling in a singular direction.

Star Topology

The most popular physical LAN topology where devices connect to a central point, commonly used with Ethernet cabling.

Hub-and-Spoke Topology

A topology used for connecting multiple sites, similar to a star topology but with WAN links instead of LAN connections.

Full-Mesh Topology

The most redundant network topology where every device is connected to every other device, providing multiple paths for data transmission.

Full-Mesh Topology

Every node connects to every other node.

Optimal Routing

Always available in a full-mesh topology.

Partial-Mesh Topology

A hybrid of full-mesh and hub-and-spoke topologies that provides optimal routes between some sites while avoiding the expense of connecting every site.

Wireless Network Topology

Infrastructure Mode:The most common type of wireless network that requires centralized management and uses a wireless access point as a centralized point like a star topology.

Wireless Network Topology

Ad Hoc Mode:A decentralized wireless network that does not require routers or access points and allows for dynamic forwarding decisions for data on the network.

Wireless Mesh Topology

Interconnection of different types of nodes or devices that consists of clients, routers, and gateways and utilizes different radio frequencies to extend and expand access.

Internet of Things (IoT) Technologies

802.11, Bluetooth, RFID, NFC, Infrared (IR), Z-Wave, Ant+.

OSI Model

A reference model consisting of 7 layers developed by the International Organization for Standardization (ISO) to categorize functions of a network and compare technologies across different manufacturers.

OSI Model Layer 1

The Physical Layer responsible for the transmission of bits across the network and the physical and electrical characteristics of the network.

Physical Layer

The layer that determines how bits are represented on the medium, wiring standards for connectors and jacks, physical topology, synchronizing bits, bandwidth usage, and multiplexing strategy.

Time-Division Multiplexing (TDM)

Each session takes turns, using time slots, to share the medium between all users.

Statistical Time-Division Multiplexing (StatTDM)

A more efficient version of TDM that dynamically allocates time slots on an as-needed basis instead of statically assigning.

Frequency-Division Multiplexing (FDM)

The medium is divided into various channels based on frequencies, and each session is transmitted over a different channel.

Layer 2 (Data Link)

The layer responsible for packaging data into frames, performing error detection/correction, and uniquely identifying network devices with a MAC address.

Data Link Layer

Provides connection services, synchronizes transmissions, and includes Media Access Control (MAC) and Logical Link Control (LLC).

Media Access Control (MAC)

The physical addressing of devices using a 48-bit address assigned to a network interface card (NIC) by the manufacturer.

Logical Link Control (LLC)

Provides connection services, acknowledgment of receipt of a message, flow control, and error control.

Layer 3 (Network)

The layer responsible for forwarding traffic (routing) with logical addressing, such as IP addresses, and includes logical addressing, switching, route discovery and selection, connection services, bandwidth usage, and multiplexing strategy.

Logical Address

The IP address (IPv4 or IPv6) used for logical addressing in the network layer.

Packet switching

Data forwarding method where data is divided into packets and forwarded.

Circuit switching

Data forwarding method where a dedicated communication link is established between two devices.

Message switching

Data forwarding method where data is divided into messages and may be stored before forwarding.

Routing

Process of forwarding data packets based on destination IP address.

Routing table

Maintained by routers to determine how to forward packets based on destination IP address.

Static route

Manually configured route in a routing table.

Dynamic route

Route dynamically learned through a routing protocol.

RIP

Routing Information Protocol, a routing protocol.

OSPF

Open Shortest Path First, a routing protocol.

EIGRP

Enhanced Interior Gateway Routing Protocol, a routing protocol.

Connection services

Layer 3 services that improve reliability by augmenting Layer 2.

Flow control

Prevents the sender from sending data faster than the receiver can handle.

Packet reordering

Allows packets to be sent over multiple links and routes for faster service.

ICMP

Internet Control Message Protocol, used for sending error messages and operational information about an IP destination.

Layer 3 examples

Routers, multilayer switches, IPv4 protocol, IPv6 protocol, ICMP.

Transport Layer

Layer 4 of the OSI model.

Segments

Data units sent at the Transport Layer.

TCP

Transmission Control Protocol, a connection-oriented and reliable transport protocol.

UDP

User Datagram Protocol, a connectionless and unreliable transport protocol.

Windowing

Allows clients to adjust the amount of data sent in each segment.

Buffering

Allocating memory to store segments if bandwidth is not readily available.

Layer 4 examples

TCP, UDP.

Session Layer

Layer 5 of the OSI model responsible for setting up, maintaining, and tearing down sessions.

Setting up a session

Process of checking credentials, assigning session numbers, negotiating session services, and determining the data sender.

Maintaining a session

Transferring data, reestablishing disconnected sessions, and acknowledging receipt of data.

Tearing down a session

Ending a session due to mutual agreement or party disconnection.

Layer 5 examples

H.323, NetBIOS.

Presentation Layer

Layer 6 of the OSI model responsible for formatting data and providing encryption.

Data formatting

Ensuring compatibility and readability of data between devices.

Encryption

Scrambling data to provide confidentiality and secure transmission.

Layer 6 examples

HTML, XML, PHP, JavaScript.

Application Layer

Layer 7 of the OSI model providing application-level services and service advertisement.

Application services

Uniting components from multiple network applications.

Service advertisement

Announcing services offered on the network.

Layer 7 examples

E-mail (POP3, IMAP, SMTP), web browsing (HTTP, HTTPS), DNS, FTP, remote access (TELNET, SSH), SNMP.

Encapsulation

Process of adding headers and sometimes trailers around data.

Decapsulation

Process of removing the encapsulation applied to data.

Protocol Data Unit (PDU)

Single unit of information transmitted within a computer network at different layers.

SYN flag

Used to synchronize the connection during the three-way handshake in TCP communications.

ACK flag

Used to acknowledge the successful receipt of packets during communication.

FIN flag

Used to tear down virtual connections created using the three-way handshake.

RST flag

Used when a client or server receives an unexpected packet during the current connection.

PSH flag

Used to prioritize and process data immediately at the sending or receiving ends.

URG flag

Used to identify incoming data as "urgent" and process it immediately.

Source and Destination ports

Dictate the source and destination of data in TCP and UDP.

Length

Indicates the number of bytes in a UDP packet, including the header and data.

Checksum

Optional field used to provide validation for the integrity of UDP data.

MAC address

Physical address used to identify a network card on a local area network.

EtherType field

Indicates the protocol encapsulated in the payload of a frame.

Encapsulation

The process of adding headers and trailers to data as it moves from higher layers to lower layers in the OSI model.