CompTIA Network+ N10-009 Last Minute Cram Guide

OSI Reference Model

A conceptual framework used to understand network interactions in seven layers.

Networking Appliances

Devices used in a network to manage, direct, and facilitate communication.

Cloud Concepts

The principles and technologies that enable the delivery of computing services over the internet.

Common Ports

Standardized communication endpoints used by various protocols in networking.

Transmission Media

The physical pathways through which data is transmitted in a network.

Network Topologies

The arrangement of different elements (links, nodes, etc.) in a computer network.

IPv4 Network Addressing

The method of assigning unique identifiers to devices on a network using 32-bit addresses.

Routing Technologies

Methods and devices used to determine the best path for data to travel across a network.

Switching Technologies

Techniques used to direct data packets between devices on the same network.

Wireless Devices

Devices that connect to a network without physical cables, using radio waves or infrared signals.

Disaster Recovery Concepts

Strategies and processes for recovering from network failures or disasters.

Network Security Concepts

Fundamental principles aimed at protecting network integrity, confidentiality, and availability.

Types of Attacks

Various methods used by malicious actors to compromise network security.

Network Security Features

Tools and techniques implemented to safeguard networks against threats.

Open Systems Interconnection (OSI) Model

A conceptual framework used to understand network interactions in seven layers.

Layer 1 - Physical

Responsible for the physical transmission of data over network media, dealing with hardware aspects including cables and switches.

Layer 2 - Data Link

Responsible for node-to-node data transfer and error detection and correction in the physical layer.

Media Access Control (MAC) layer

A sublayer of the Data Link Layer that manages protocol access to the physical network medium.

Logical Link Control (LLC) layer

The upper sublayer of the Data Link Layer that provides multiplexing mechanisms for multiple network protocols to coexist.

Layer 3 - Network

Responsible for logical addressing and routing of packets across different networks.

Layer 4 - Transport

Responsible for providing reliable, transparent transfer of data between end systems.

Framing of data packets

The process handled by the Data Link Layer that includes addressing.

Routing protocols

Protocols that determine the best path for data transmission from the source to the destination.

Packet forwarding

The management of routing through intermediate routers in the Network Layer.

Error correction

Mechanisms in the Transport Layer that ensure complete data transfer.

Flow control

A mechanism in the Transport Layer that manages the rate of data transmission.

Segmentation/de-segmentation of data

Processes in the Transport Layer that break down and reassemble data for transmission.

Interoperability

The ability to work across diverse network technologies and protocols facilitated by the OSI model.

Standardization

The establishment of common standards for devices and media to connect and transmit raw bits.

Network congestion

A condition in the Network Layer where the demand for network resources exceeds the available capacity.

Packet filtering

The process of controlling the flow of packets based on predetermined security rules.

Physical Layer

The OSI model layer that defines the standards for devices and media to connect and transmit raw bits.

Data Link Layer

The OSI model layer that establishes, maintains, and terminates connections between two physically connected devices.

Network Layer

The OSI model layer that manages packet forwarding and routing through different networks.

Transport Layer

The OSI model layer responsible for reliable data transfer and error correction.

Layer 5 - Session

The OSI model's Layer 5, known as the Session Layer, manages the setup, maintenance, and termination of sessions between presentation layer entities.

Session Layer

This layer establishes, manages, and terminates the connections between the local and remote applications.

Session Layer Functions

It provides mechanisms for controlling the dialog between the two end systems, either half-duplex or full-duplex.

Layer 6 - Presentation

The OSI model's Layer 6, known as the Presentation Layer, is responsible for the translation, encryption, and compression of data between the application and network formats.

Presentation Layer

This layer ensures that data is presented in a usable format and mediates between the data formats and protocols used by the network and the applications.

Presentation Layer Functions

It acts as a translator, providing data encryption and compression services to ensure secure and efficient data transfer.

Layer 7 - Application

The OSI model's Layer 7, known as the Application Layer, serves as the interface between the user and the network services.

Application Layer

This layer facilitates the end-user processes and applications to access network services.

Application Layer Protocols

It defines protocols for various network services like file transfers, email, and web browsing, ensuring seamless communication between software applications and the network.

Physical Appliances

Physical appliances are dedicated hardware devices focused on specific network functions, offering high performance and reliability but at a higher cost and with space requirements.

Virtual Appliances

Virtual appliances are software-based solutions that run on virtual machines, providing similar functionalities with greater flexibility, scalability, and cost efficiency, but potentially at the expense of raw performance.

Router

A router operates at the network layer of the OSI model, directing data packets between different networks based on IP addresses.

Router Functions

Routers use routing tables to determine the best path for forwarding packets to their destination, connecting multiple networks together, such as a local network to the Internet.

Router Security Features

Routers also provide network security features like firewalls and VPN support.

Layer 2 Switch

A Layer 2 switch operates at the data link layer of the OSI model, forwarding data based on MAC addresses.

Layer 2 Switch Functions

It creates separate collision domains for each port, improving network efficiency by reducing collisions.

Layer 2 Switch Usage

Layer 2 switches are used to connect devices within the same network or VLAN.

Layer 3 Capable Switch

A Layer 3 capable switch, also known as a multilayer switch, operates at both the data link layer and the network layer.

Layer 3 Switch Functions

It can perform routing functions, forwarding data based on IP addresses, in addition to switching functions.

Layer 3 Switch Benefits

This enables the switch to interconnect different subnets or VLANs within the same device, facilitating efficient network segmentation and routing.

Firewall

A firewall is a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on a defined set of security rules.

Firewall Purpose

Firewalls are crucial for establishing a barrier between secure internal networks and untrusted external networks, such as the internet, and can be hardware-based, software-based, or a combination of both.

IPS/IDS Device

An IPS/IDS device monitors network and/or system activities for malicious activities or policy violations.

IDS vs IPS

An IDS passively monitors and alerts system administrators of suspicious activity, whereas an IPS actively blocks or prevents such activities based on detected anomalies, signatures, and policies to protect the network from threats.

Load Balancer

A load balancer distributes incoming network traffic across multiple servers to ensure no single server becomes overwhelmed, improving the reliability and availability of applications.

Proxy Server

A proxy server acts as an intermediary between a user's device and the internet, receiving requests from clients, forwarding them to the relevant server, and returning the server's response to the client.

Network-Attached Storage

NAS is a dedicated file storage device connected to a network, allowing multiple users and client devices to retrieve and store data from a centralized location.

Storage Area Network (SAN)

A Storage Area Network (SAN) is a dedicated, high-speed network that provides access to consolidated, block-level data storage.

Access Point

An access point (AP) is a networking device that allows wireless devices to connect to a wired network using Wi-Fi or related standards.

Wireless LAN Controller (WLC)

A Wireless LAN Controller manages wireless access points in a network, centralizing control of the wireless LAN (WLAN).

Content Delivery Network (CDN)

A globally distributed network of proxy servers and data centers designed to deliver internet content rapidly to users.

Virtual Private Network (VPN)

A Virtual Private Network (VPN) is a technology that creates a safe and encrypted connection over a less secure network, such as the internet.

Quality of Service (QoS)

Quality of Service (QoS) refers to the set of technologies and policies used to manage and prioritize network traffic to ensure the performance of critical applications and services.

Time to Live (TTL)

Time to Live (TTL) is a field in the header of IP packets that specifies the maximum time or number of hops a packet is allowed to traverse before being discarded by a router.

Network Traffic Optimization

Load balancers make decisions based on IP addresses, TCP/UDP ports, or application-level content to optimize resource use, maximize throughput, minimize response time, and avoid overload of any single resource.

Content Caching

Proxy servers can provide additional functionality such as content caching, access control, and filtering, enhancing security and performance.

File-Based Protocols

NAS systems support a variety of file-based protocols such as NFS, SMB/CIFS, and AFP.

Data Management

SANs are designed to handle large volumes of data transfers, improving the availability and performance of applications by offloading storage functions and direct access to multiple storage devices.

Wireless Coverage Extension

APs extend the wireless coverage of a network and can manage multiple connections simultaneously, providing network access to wireless devices within their range.

Wireless Network Management

WLCs simplify the deployment and management of wireless networks, including configuration, security policies, and managing guest access.

Latency Reduction

CDNs cache content like web pages, videos, and images in multiple locations around the world to reduce latency and improve access speed for users regardless of their location.

Secure Data Transmission

VPNs are used to establish secure connections between remote users or remote sites and an organization's private network.

Traffic Prioritization

QoS assigns different priorities to different types of traffic, ensuring that essential services like voice and video communications are given higher priority over less critical data.

User Experience Enhancement

QoS helps in reducing latency, jitter, and packet loss, enhancing the overall user experience in networks with limited bandwidth.

TTL

Helps prevent packets from looping indefinitely in the network, with each router decrementing the TTL value by one until it reaches zero, at which point the packet is dropped.

Network Functions Virtualization (NFV)

Involves the decoupling of network functions from hardware devices and running them as software instances on virtual machines or containers.

NFV in Cloud Computing

Allows for flexible deployment and management of networking services like firewalls, load balancers, and intrusion detection systems.

Benefits of NFV

Reduces the need for dedicated hardware and enables dynamic scaling and management, which enhances resource utilization and reduces costs.

Virtual Private Cloud (VPC)

An isolated network space within a public cloud designed to provide a similar level of segmentation, control, and security as a private data center.

VPC User Control

Users can define their own IP address range, configure subnets, route tables, and network gateways.

Network Security Groups

Used to control inbound and outbound traffic to cloud resources within a VPC.

Function of Network Security Groups

Act as a virtual firewall for associated instances to control traffic based on rules that specify allowed or denied ports, protocols, and source/destination IP addresses.

Network Security Lists

Used for managing and securing network traffic in a cloud environment, providing stateful or stateless traffic filtering on a subnet level.

Cloud Gateways

Serve as intermediary devices or services that connect cloud environments with different networks, including private data centers or other cloud services.

Function of Cloud Gateways

Facilitate communication, data transfer, and management between disparate environments, ensuring secure and efficient access to cloud resources.

Internet Gateway

Serves as a bridge between a company's VPC and the internet, enabling internet access for the resources within the VPC.

NAT Gateway

Allows instances in a private subnet to connect to the internet while preventing the internet from initiating a connection with those instances.

Purpose of NAT Gateway

Crucial for instances that require outbound internet access but do not need inbound internet connections.

Cloud Connectivity Options

Refer to the various methods through which data and applications can connect to and interact with cloud environments.

VPN Usage

Used to establish secure connections between remote users or remote sites and an organization's private network.

Private-Direct Connection to Cloud Provider

A dedicated network link between an organization's on-premises infrastructure and a cloud service provider's data center.

Direct Connection

This direct connection bypasses the public internet, offering more reliable, secure, and faster connectivity for accessing cloud services.

Deployment Models

Deployment models in networking and cloud computing refer to the specific configurations and environments in which technology services and infrastructure are implemented.

Public Deployment Model

A public deployment model provides services over the Internet to multiple customers or the general public, where infrastructure and resources are owned and operated by the service provider.

Private Deployment Model

A private deployment model is dedicated to a single organization and can be hosted on-premises or by a third-party provider.