Module 1-7 drei yu

They enable communication, online collaboration, video streaming, and access to services that impact daily routines.

Devices that originate or receive messages on a network (e.g., computers, phones).

Clients request services; servers provide them (e.g., a client requests a webpage from a web server).

A network where devices can act as both clients and servers.

Easy to set up, low cost, less complex.

Not scalable, less secure, lacks centralized management.

Devices that connect end devices and direct data traffic, such as switches and routers.

Signal regeneration, path selection, and error notification.

The physical means for data transmission—copper, fiber-optic, or wireless.

By electrical impulses.

By pulses of light.

Using electromagnetic waves.

A layout showing physical placement of devices and cabling.

A map showing how devices communicate and their addressing scheme.

A Local Area Network within a small geographic area, managed by one organization.

A Wide Area Network that connects LANs over a broad geographic area.

A global network of interconnected LANs and WANs, not owned by any one entity.

A private network accessible only to an organization’s members.

A private network that allows limited access to outsiders like suppliers or partners.

Cable, DSL, cellular, satellite, and dial-up.

Business DSL, leased lines, and Metro Ethernet.

A single network infrastructure carrying data, voice, and video.

The ability of a network to continue operating despite failures by using redundancy.

The ability to expand the network easily without performance issues.

Managing network traffic to prioritize time-sensitive data like voice or video.

Infrastructure security and information security.

Protecting the physical devices and preventing unauthorized access.

Protecting transmitted data for confidentiality, integrity, and availability.

Bring Your Own Device – allowing personal devices to connect to a company network.

Using tools like Cisco WebEx to work on shared projects remotely.

Video calls and conferencing that enhance collaboration.

Storing and accessing data and applications over the internet.

Cloud services available to anyone.

Cloud services dedicated to a single organization.

A combination of public and private clouds.

Cloud solutions tailored to a specific industry.

Network-connected household devices that automate tasks.

Using electrical wiring to transmit network signals.

Viruses, worms, spyware, data theft, and zero-day attacks.

Lost/stolen devices, accidental misuse, or intentional harm by insiders.

Antivirus software and firewalls.

Firewalls, ACLs, IPS, and VPNs.

Blocks unauthorized network access.

Cisco Certified Network Associate – a certification validating foundational networking skills.

A Cisco Networking Academy tool for helping students find job opportunities.

To manage hardware resources and provide a user interface for configuration and monitoring.

CLI (Command Line Interface) and GUI (Graphical User Interface)

Shell, Kernel, Hardware

Provides direct local access for initial configuration.

SSH (Secure Shell)

SSH is secure (encrypted); Telnet sends data in plaintext.

PuTTY, Tera Term, SecureCRT

>

#

Use the enable command

Use the configure terminal command

end or Ctrl+Z

A specific parameter defined by the OS (e.g., ip, interface)

A value defined by the user (e.g., an IP address)

Use ? to see available commands or arguments

service password-encryption

line console 0, then password and login

enable secret [password]

banner motd # [message] #

copy running-config startup-config

reload

erase startup-config

In RAM (volatile memory)

In NVRAM (non-volatile memory)

VLAN 1 (Switch Virtual Interface)

no shutdown

Four decimal numbers separated by dots (e.g., 192.168.1.1)

128 bits, represented in hexadecimal

Control Panel > Network > Adapter Properties > IPv4 Settings

DHCP

Manual and Automatic (DHCP)

To test end-to-end communication

Use show running-config or show startup-config

A source (sender), destination (receiver), and channel (media).

Rules that define how data is communicated between devices.

Converting data into a transmittable format; decoding happens at the destination.

Structuring data into a specific format and enclosing it for transmission.

To avoid network congestion.

Flow control, response timeout, and access method.

Controls the rate of data transmission.

Time a device waits before retransmitting or taking action.

Determines when a device is allowed to send data to avoid collisions.

One-to-one communication between devices.

One-to-many communication for specific groups.

One-to-all communication on a network.

Sets of rules that govern data formatting, addressing, and transmission.

Addressing, reliability, flow control, sequencing, error detection.

Labeling data segments to ensure correct reassembly.

Multiple protocols stack and work together (e.g., HTTP → TCP → IP → Ethernet).

A group of related protocols used for network communication.

TCP/IP, OSI, AppleTalk, Novell NetWare.

An open standard used widely on the Internet.

A 7-layer model used to standardize network functions.

Application, Presentation, Session, Transport, Network, Data Link, Physical.

Handles process-to-process communication.

Ensures reliable delivery and reassembly of data segments.

Manages IP addressing and routing of packets.

Provides physical addressing (MAC) and reliable delivery over the media.

Handles bit transmission over the physical medium.

A 4-layer model that mirrors the protocol stack used on the Internet.

Application, Transport, Internet, Network Access.

Wrapping data with headers/trailers at each protocol layer before transmission.

Removing protocol headers/trailers at the receiving device.

The name for data at each layer of the model.

Data

Segment

Packet

Frame

Bits

Dividing large messages into smaller units for faster and more reliable transmission.

IP addresses used by Layer 3 to deliver data across networks.

A physical address used by Layer 2 to deliver data within the same network.

No, it remains the same from source to destination.

Yes, it changes at each hop (e.g., between routers).

The MAC address of the destination device is used directly.

The frame uses the MAC address of the default gateway; the packet keeps the original IP address.

The router's IP that connects a local network to external networks.

A publicly available protocol that promotes interoperability.

ISOC, IETF, IAB, IRTF, IEEE, ICANN, IANA, ITU-T, EIA, TIA.

IP address allocation, domain names, and protocol identifiers.

Standards for Ethernet and wireless LAN technologies.

A physical connection (wired or wireless) must be established using a NIC.

To transport bits across the network media by converting frames into signals.

Physical components, encoding, and signaling.

Organizations like ISO, EIA/TIA, ITU-T, ANSI, and IEEE.

Converting bits into a recognizable signal pattern (e.g., Manchester encoding).

The method used to represent 1s and 0s on the transmission medium.

The capacity at which a medium can carry data, measured in bps.

The time it takes for data to travel from source to destination.

The actual rate of successful data transfer over a period.

The measure of usable data transferred, excluding protocol overhead.

The weakening of a signal as it travels across a medium.

Electromagnetic and radio frequency interference that can distort signals in copper cables.

Interference caused when signals from one wire pair affect another wire pair.

UTP, STP, and coaxial.

Unshielded Twisted Pair – the most common network cable using twisted wire pairs.

Shielded Twisted Pair – copper cable with added shielding for better noise protection.

Cable internet and wireless antenna connections.

Using wire pair cancellation and varying twist rates.

TIA/EIA and IEEE.

Category 3, 5e, and 6 – based on performance.

They are different wiring standards used for terminating UTP cables.

To connect different devices (e.g., host to switch).

To connect similar devices (e.g., switch to switch).

A feature in modern NICs that auto-detects cable types and adjusts accordingly.

Thin strands of pure glass that transmit data as light pulses.

Higher bandwidth, longer distance, and immunity to EMI/RFI.

Fiber with a small core for long distances using lasers.

Fiber with a larger core for short distances using LEDs.

ST, SC, and LC.

Yellow

Orange or aqua

Data transmission using radio or microwave frequencies.

Limited coverage, interference, security risks, and shared bandwidth.

IEEE 802.11 (Wi-Fi)

IEEE 802.15

Broadband wireless access (IEEE 802.16).

Low-power IoT applications (IEEE 802.15.4).

Connects wireless devices to a wired network.

A wireless NIC adapter.

To enable communication between Network Interface Cards (NICs) and prepare data for transmission over the physical medium.

It encapsulates them into Layer 2 frames.

Logical Link Control (LLC) and Media Access Control (MAC).

It communicates between the network software and device hardware.

It handles data encapsulation and controls access to the media.

Accept a frame, de-encapsulate it, re-encapsulate the packet, forward the new frame.

IEEE, ITU, ISO, and ANSI.

The physical layout and cabling of devices on a network.

The way data flows logically between devices, including virtual paths.

A direct connection between two endpoints.

A central site connects to multiple branch sites via point-to-point links.

Each device connects to every other device for high availability.

All devices connect to a central point like a switch.

A star topology with multiple interconnected central devices.

A single cable connects all devices in a chain (legacy).

Devices are connected in a circular path (legacy).

Only one device can send or receive at a time.

Devices can send and receive data at the same time.

All nodes compete for access to the network medium.

Carrier Sense Multiple Access with Collision Detection – used in legacy Ethernet to detect and handle collisions.

Carrier Sense Multiple Access with Collision Avoidance – used in WLANs to avoid collisions.

A method where each node has its own time to use the medium.

Token Ring.

Header, data (Layer 3 packet), and trailer.

Source and destination addresses, and other control info.

Error detection information, like a CRC.

They identify where the frame begins and ends.

It identifies the source and destination on the local link.

It indicates the Layer 3 protocol encapsulated (e.g., IPv4 or IPv6).

It identifies flow control services.

It contains the Layer 3 packet being transported.

It verifies the integrity of the frame (e.g., CRC).

Physical addresses or MAC addresses.

At every hop (each forwarding device updates them).

Ethernet, PPP, and 802.11 Wireless.

Cyclic Redundancy Check – an error-detection method used in the trailer of a frame.

IEEE 802.2 and IEEE 802.3

Logical Link Control (LLC) and Media Access Control (MAC)

To identify the network layer protocol used in the frame

To handle encapsulation, addressing, and media access control

Legacy uses hubs and half-duplex; modern uses switches and full-duplex

CSMA/CD (Carrier Sense Multiple Access with Collision Detection)

Minimum is 64 bytes, maximum is 1518 bytes

A frame smaller than 64 bytes

A frame with more than 1500 bytes of data

Preamble, SFD, Destination MAC, Source MAC, Type/Length, Data, FCS

48 bits or 6 bytes

12 hexadecimal digits

The Organizationally Unique Identifier (OUI) assigned by the IEEE

It checks if the destination MAC matches its own, a broadcast, or a multicast group

An address used to send a frame to one specific device

FF-FF-FF-FF-FF-FF, processed by all devices on a LAN

An address used to send a frame to a specific group of devices
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