Computer Networks

Flashcards related to key vocabulary and concepts in Computer Networks.

Network Interface Card (NIC)

Physically connects end devices to the network.

Physical Port

Connector/outlet on a networking device where the media connects to an end device or another networking device.

Interface

Specialized ports on a networking device that connect to individual networks; ports on a router are referred to as network interfaces.

LAN (Local Area Network)

Interconnects end devices in a limited area, administered by a single organization, and provides high-speed bandwidth.

WAN (Wide Area Network)

Interconnects LANs over wide geographical areas, typically administered by service providers, providing slower speed links between LANs.

IETF (Internet Engineering Task Force)

Helps maintain structure on the internet.

ICANN (Internet Corporation for Assigned Names and Numbers)

Helps maintain structure on the internet.

IAB (Internet Architecture Board)

Helps maintain structure on the internet.

Intranet

Private collection of LANs and WANs internal to an organization, accessible only to authorized members.

Extranet

Network that provides secure access to an organization's network for external collaborators.

Fault Tolerance

Network characteristic that limits the impact of a failure by using redundant connections.

Scalability

Network characteristic where the network can expand quickly and easily to support new users and applications without impacting existing users.

Quality of Service (QoS)

Prioritizes time-sensitive traffic to manage data flow and ensure reliable content delivery.

Confidentiality

Network security goal ensuring only intended recipients can read the data.

Integrity

Network security goal ensuring data is not altered during transmission.

Availability

Network security goal ensuring timely and reliable access to data for authorized users.

BYOD (Bring Your Own Device)

Policy allowing users to use their own devices to access network information.

Cloud Computing

Storing files and backing up data on remote servers over the internet.

Public Cloud

Cloud services available to the general public through pay-per-use or free models.

Private Cloud

Cloud infrastructure intended for a specific organization.

Hybrid Cloud

Combination of two or more cloud types connected using the same architecture.

Community Cloud

Public cloud with set levels of security, privacy, and regulatory compliance.

Threat Vectors

Methods by which threats access a network, either external or internal.

Shell

User interface to request tasks from the computer via CLI or GUI.

Kernel

Communicates between hardware and software, managing hardware resource use.

Hardware

Physical components of a computer, including electronics.

Console

Physical management port for local device access and maintenance.

Secure Shell (SSH)

Secure remote CLI connection through a virtual interface over a network.

Telnet

Insecure remote CLI connection over a network, sending data in plaintext.

User EXEC Mode

Cisco IOS mode with limited monitoring commands, identified by a > symbol.

Privileged EXEC Mode

Cisco IOS mode with access to all commands, ending with a # symbol.

Global Configuration Mode

Cisco IOS mode used to access configuration options on the device.

Running-config

Stored in RAM, loses all of its content when device is powered off .

Startup-config

Saved configuration that is stored NVRAM

IP Addresses

Primary means of enabling devices to locate one another and establish end-to-end communication.

IPv4 Address

Dotted decimal notation, 4 decimal numbers between 0-255.

IPv4 Subnet Mask

32-bit value that differentiates the network portion of the address from the host portion.

Default Gateway

IP address of the router that the host will use to access remote networks.

IPv6 Address

128 bits in length, written as a string of hexadecimal values.

MAC Address

48-bit hexadecimal address that uniquely identifies a network card.

Half-Duplex Communication

Only allows one device to send or receive at a time on a shared medium.

Full-Duplex Communication

Allows both devices to simultaneously transmit and receive on a shared medium.

Attenuation

Weakening of electrical signals over long distances in copper cabling.

Electromagnetic Interference (EMI)

Interference that can distort and corrupt data signals.

Radio Frequency Interference (RFI)

Interference that can distort and corrupt data signals.

Unshielded Twisted-Pair (UTP)

A common networking media terminated with RJ-45 connectors.

Shielded Twisted-Pair (STP)

Better noise protection, more expensive, harder to install.

Data Link Layer

Responsible for communication between end-device network interface cards.

Network Layer

Provides services to allow end devices to exchange data.

Transport Layer

Responsible for logical communications between applications running on different hosts.

Application Layer

Provides the interface between applications and the underlying network.