CCNA Networking Fundamentals Flashcards

Educational flashcards covering terminology for TCP/IP networking, Ethernet LANs, and IP routing fundamentals based on Chapters 1-3 of the CCNA Official Cert Guide.

Networking model

A comprehensive set of documents that collectively define everything that should happen for a computer network to work, also known as a networking architecture or blueprint.

Protocol

A set of logical rules that devices must follow to communicate.

Application Layer

The TCP/IP layer that provides an interface between software running on a computer and the network itself (e.g., HTTP, POP3, SMTP).

Transport Layer

The TCP/IP layer that provides services to application layer protocols, such as error recovery (e.g., TCP, UDP).

Adjacent-layer interaction

The concept of how adjacent layers in a networking model on a single computer work together to provide and consume services.

Same-layer interaction

The process where two computers use a protocol to communicate with the same layer on the other computer by using headers.

Encapsulation

The process of putting headers (and sometimes trailers) around some data.

Segment

The term used specifically to identify the entity created when encapsulating data inside transport layer headers.

Packet

The term used specifically to identify the entity created when encapsulating data inside network layer (IP) headers.

Frame

The term used specifically to identify the entity created when encapsulating data inside data-link layer headers and trailers.

PDU

Protocol Data Unit; an OSI term representing the bits including the headers, trailers, and encapsulated data for a specific layer.

Ethernet

A family of LAN standards defined by the IEEE that together define the physical and data-link layers of wired LAN technology.

SOHO

Small Office/Home Office; refers to small networks used for business purposes in home-based environments.

Switch

A networking device that provides physical ports to connect Ethernet nodes and forwards data-link frames using MAC addresses.

Router

A networking device that connects different parts of a TCP/IP network together for the purpose of forwarding IP packets.

UTP

Unshielded Twisted Pair; a type of copper cabling where wires are twisted to help cancel out electromagnetic interference ($EMI$).

RJ-45

The standard connector type used for Ethernet UTP cables, containing $8$ pin positions.

MAC Address

A $6$-byte ($48$-bit) binary number, often listed in hexadecimal, representing a unique interface on an Ethernet network.

OUI

Organizationally Unique Identifier; the first $3$ bytes of a MAC address assigned to a manufacturer by the IEEE.

BIA

Burned-in address; the permanent MAC address encoded into the ROM chip on a NIC or Ethernet interface.

Broadcast address

An Ethernet address consisting of $FFFF.FFFF.FFFF$ that signifies the frame should be delivered to all devices on the LAN.

Full duplex

A duplex mode where a device does not have to wait to send and can send and receive at the same time.

Half duplex

A duplex mode where a device cannot send and receive simultaneously and must wait if a frame is currently being received.

CSMA/CD

Carrier sense multiple access with collision detection; the algorithm used by nodes in half-duplex Ethernet to manage collisions.

Leased line

A point-to-point serial WAN link (or circuit) leased from a telco that delivers bits at a predetermined speed.

HDLC

High-Level Data Link Control; a data-link protocol for leased lines ($ISO$ standard) often used with a Cisco-proprietary Type field.

EoMPLS

Ethernet over MPLS; an Ethernet WAN service that logically behaves as a point-to-point Ethernet connection between two routers.

Default Router

Also called a default gateway; the router on the same local subnet to which a host sends IP packets when the destination is in a remote subnet.

ARP

Address Resolution Protocol; a method used on LANs to dynamically learn the MAC address corresponding to a known IP address.

DNS

Domain Name System; a system used to resolve Easy-to-read hostnames into matching IP addresses for network communication.

Ping

A command that uses the Internet Control Message Protocol ($ICMP$) echo request and reply to test basic IP connectivity.

Routing Protocol

A protocol used by routers to advertise about networks and subnets and learn the best paths through an internetwork.

¿Qué es same-layer interaction?

Comunicación horizontal entre la misma capa en dispositivos distintos. Ejemplo: TCP en PC1 se comunica lógicamente con TCP en PC2.

¿Qué es adjacent-layer interaction?

Comunicación vertical entre capas adyacentes dentro del mismo dispositivo. La capa superior usa los servicios de la capa inferior.

PDU names por capa TCP/IP

Transport = Segment
Network = Packet
Data Link = Frame
Physical = Bits

¿Cómo distingues Same-layer de Adjacent-layer en un escenario?

Same-layer = misma capa, dispositivos distintos. Adjacent-layer = capas distintas, mismo dispositivo.