Cisco Networking Basics - Modules 1-8

Network

A collection of interconnected devices that communicate with each other to exchange data

Bit

The smallest unit of data, representing one of two discrete states (0 or 1)

Byte

A group of eight bits

Bandwidth

The capacity of a medium to carry data, measured in bits per second (bps)

Throughput

The actual rate of data transfer over a network, which may be less than bandwidth due to latency

Latency

The amount of time, including delays, for data to travel from one point to another

Client

A computer that requests services from a server

Server

A computer that provides services or resources to clients

Peer-to-Peer Network (P2P)

A network where computers can act as both clients and servers

Host

Any device connected to a network that participates in network communication

SOHO Network

Small Office/Home Office network that shares resources among a few users

Metal wires (Copper cable)

Network media that encodes data as electrical impulses

Fiber-optic cable

Network media that encodes data as pulses of light

Wireless transmission

Network media that encodes data via modulation of electromagnetic waves

Twisted-pair cable

The most common type of wired media used in Ethernet LANs

Coaxial cable

Wired media commonly used by TV companies to connect to set-top boxes

Electrical signals

Data transmission achieved by representing bits as electrical pulses on copper wire

Optical signals

Data transmission achieved by converting electrical signals into light pulses

Wireless signals

Data transmission using infrared, microwave, or radio waves

ASCII

American Standard Code for Information Interchange; code that represents characters with 8 bits each

Kbps

Kilobits per second; 1,000 bits per second

Mbps

Megabits per second; 1,000,000 bits per second

Gbps

Gigabits per second; 1,000,000,000 bits per second

Internet

A worldwide collection of interconnected networks cooperating to exchange information

WWW (World Wide Web)

A system of interconnected documents and resources accessed via the Internet

IP Address

A unique numerical identifier assigned to a device on a network

DHCP

Dynamic Host Configuration Protocol; automatically assigns IP addresses to devices

MAC Address

Media Access Control address; a unique identifier for a device on a local network

Switch

A network device that connects devices on the same local network

Router

A network device that connects different networks and forwards data between them

Gateway

A device that connects a local network to external networks or the Internet

ISP

Internet Service Provider; company that provides access to the Internet

Modem

Device that converts signals between ISP and a home/business network

Wi-Fi

Wireless networking technology that allows devices to connect without cables

Ethernet

Wired networking technology commonly used in LANs

Protocol

A set of rules governing data transmission and communication between devices

TCP (Transmission Control Protocol)

A connection-oriented protocol that ensures reliable delivery of data

UDP (User Datagram Protocol)

A connectionless protocol that prioritizes speed over reliability

DNS

Domain Name System; translates domain names to IP addresses

HTTP

Hypertext Transfer Protocol; used for web browsing

HTTPS

Secure version of HTTP that encrypts data in transit

FTP

File Transfer Protocol; used for transferring files over a network

Ping

A utility that tests connectivity between devices

Traceroute

A utility that shows the path data takes through a network

IPv4

Internet Protocol version 4; uses 32-bit addresses

IPv6

Internet Protocol version 6; uses 128-bit addresses for more available addresses

Subnet Mask

A mask that determines which part of an IP address is the network portion

Default Gateway

The IP address of the router that connects a local network to external networks

ARP (Address Resolution Protocol)

A protocol that maps IP addresses to MAC addresses

PAT (Port Address Translation)

A technique that allows multiple devices to share a single public IP address

NAT (Network Address Translation)

A technique that translates between private and public IP addresses

Firewall

A security device that monitors and controls incoming and outgoing network traffic

ACL (Access Control List)

A set of rules that determine which traffic is allowed or denied

Authentication

The process of verifying the identity of a user or device

Encryption

The process of encoding data to prevent unauthorized access