CompTIA Network + Ethernet Switching

10Base-T Ethernet

Allowed up to 10 Mbps networks to be run over a twisted pair cable known as category 3 or Cat 3

Deterministic

Means that the network access should be very organized and orderly

Contention-based

Used to determine who gets to access and communicate on the network at any given time

CSMA/CD

Carrier Sense Multiple Access with Collision Detection

Carrier

Fancy word in electronics for a signal that carries information or data

Random Backoff Timer

Allows the two devices to attempt to retransmit again when the timer hits zero

Collision Domain

Each area of the network that shares a single segment

Ethernet Switch

Increases scalability of a network by creating multiple collision domains (Full-duplex mode when connected to switch)

Hub

Known as multiport repeater, is is a Layer 1 device that connects multiple network devices and workstations

Passive Hub

Repeats signal with no amplification

Active Hub

Repeats signal with amplification

Smart Hub

Active hub with enhanced features like Simple Network Management Protocol (SNMP)

Bridge

Analyzes source MAC addresses and makes intelligent forwarding decisions based on the destination MAC in the frames

Switch

Known as a multiport bridge, it is a Layer 2 device that connects multiple network segments together

Router

Layer 3 device that connects multiple networks and makes forwarding decisions based on logical network information

Layer 3 Switch

Makes Layer 3 routing decisions and then interconnects entire networks, not just network segments

Virtual Local Area Network (VLAN)

Logical subdivision of a given network that segments into separate broadcast domains

Enhanced Security

Segmenting the networks into VLANs allows sensitive data to be isolated to reduce data breaches

Improved Performance

Reducing the size of a broadcast domain helps to decrease the amount of traffic being sent over that segment

Increased Management

Providing greater control over the management of networks to implement policy changes and troubleshoot issues

Improved Cost Efficiency

Breaking the existing network infrastructure into smaller logical segments

Switch Virtual Interface (SVI)`

Allows switching to route traffic between different VLANs without requiring a separate router

802.1Q (VLAN) Tagging

Refers to an IEEE standard that facilitates the management of multiple VLANs on a single network

Trunking

The transmission of traffic from different VLANs across the same physical network infrastructure, while keeping the traffic from each VLAN separate and secure

Native (Default) VLAN

The one VLAN on a trunk port that does not get tagged with a VLAN identifier when frames are passed over a trunk link

Voice VLAN

Specialized BLAN dedicated to voice traffic, particularly VoIP (or Voice traffic over IP) traffic within the network.

Link Aggregation

Also known as port channeling or bonding, is a method used in networks to combine multiple network connections into a single, logical link

Speed and Duplex Configurations

The settings that determine the rate at which data is transmitted and the mode of communication between the network devices

Half-Duplex Mode

Data transmission and reception cannot occur simultaneously

Full-Duplex Mode

Allows a device to send and receive data simultaneously

Auto-Negotiation

Commonly used when devices automatically select the highest performance settings in common

Spanning Tree Protocol (802.1d)

Permits redundant links between switches and prevents looping of network traffic

Broadcast Storm

Multiple copies of frames being forwarded back and forth which then consumes the network

Root Bridge

Switch with the lowest bridge ID (BID)

Root Port

Every non-root bridge has a single root port which is the closest to the root bridge in terms of cost

Designated Port

Every network segment has a designated port which is the closest to the root bridge in terms of cost

Non-Designated Port

Ports that block traffic to create loop-free topology

Blocking

BPDUs are received but not forwarded

Listening

Populates the MAC address table but does not forward frames

Learning

Processes BPDUs and this is where switch determines its role in the spanning tree

Forwarding

Forwards frames for operations

Link Cost

Associated with the speed of the link - the lower the link’s speed, the higher the cost

Network Access Control (NAC)

Method for increasing the security of a given network by inspecting devices trying to connect to a network

Port Security

Involves securing physical network ports to prevent unauthorized access

MAC Filtering

Controls access to the network by limiting which devices can gain access to the network based on the device’s unique MAC address

802.1x Authentication

Provides an authentication framework for networks and ensures only authenticated users can access network services

EAP

Extensible Authentication Protocol

Supplicant

User device seeking to access the network

Authenticator

Network device the user wants to connect to

Authenticator Serv er

Server on the network that will authenticate t he user’s devices

Time-Based Access Control

Limits a device’s network access to specified hours based on the organization’s operational schedule

Location-Based Access Control

Enhances network security by utilizing geolocation technologies to verify the physical location of the device requesting network access

Role-Based Access Control

Provides a dynamic method of regulating access based on the user’s role within an organization

Rule-Based Access Control

Operates on a set of predefined rules to methodically grant or deny access by assessing logical conditions and statements based on the specific user’s identity and context.

Maximum Transition Unit (MTU)

Refers to the largest size of a data packet or frame that can be sent over a network

Jumbo Frames

Refers to any frames that exceed the standard or default Ethernet MTU size of 1500 bytes