[DCN] Number Systems, Data Link Layer and Ethernet Switching FC

Binary Number System

Consists of 1s and 0s, called bits.

Decimal Number System

Uses digits from 0 to 9 for representation.

Binary Addressing

Identifies hosts using 32-bit addresses.

Octet

8 bits in a binary address.

Dotted Decimal

Human-readable format of binary addresses.

Positional Notation

Value depends on digit's position in sequence.

IPv4 Addresses

32-bit binary addresses for network devices.

Hexadecimal Number System

Base 16 system using 0-9 and A-F.

IPv6 Addresses

128-bit addresses using hexadecimal representation.

Hextet

Group of four hexadecimal characters in IPv6.

Conversion Binary to Decimal

Process of translating binary to decimal values.

Conversion Decimal to Binary

Method to convert decimal to binary format.

Data Link Layer

Facilitates communication between network interface cards.

Layer 2 Frames

Encapsulates Layer 3 packets for transmission.

Error Detection

Identifies and rejects corrupt data frames.

IEEE 802 Standards

Defines LAN/MAN data link layer protocols.

Logical Link Control (LLC)

Communicates between software and hardware layers.

Media Access Control (MAC)

Controls data encapsulation and access to media.

Frame De-encapsulation

Process of exposing encapsulated packets from frames.

Frame Re-encapsulation

Encapsulating packets into new frames for forwarding.

Data Link Layer Functions

Four basic functions performed by routers.

Binary to Hexadecimal Conversion

Translates binary strings into hexadecimal digits.

Hexadecimal to Decimal Conversion

Converts hexadecimal numbers into decimal values.

IEEE

Institute for Electrical and Electronic Engineers organization.

ITU

International Telecommunications Union for global standards.

ISO

International Organization for Standardization, develops standards.

ANSI

American National Standards Institute, coordinates US standards.

Physical Topology

Shows actual physical connections between devices.

Logical Topology

Defines virtual connections using IP addressing schemes.

Point-to-Point Topology

Direct link between two endpoints in WAN.

Hub and Spoke Topology

Central site connects branch sites via links.

Mesh Topology

Every system connects to every other system.

Star Topology

Devices connected to a central hub.

Extended Star Topology

A star topology with additional hubs.

Bus Topology

All systems chained and terminated at ends.

Ring Topology

Each system connects to two neighbors forming a ring.

Half-Duplex Communication

One device sends or receives at a time.

Full-Duplex Communication

Devices transmit and receive simultaneously.

Contention-Based Access

Nodes compete for medium access in half-duplex.

Controlled Access

Deterministic access with scheduled time for nodes.

CSMA/CD

Carrier Sense Multiple Access with Collision Detection.

CSMA/CA

Carrier Sense Multiple Access with Collision Avoidance.

Data Link Frame

Encapsulates data with header and trailer.

Layer 2 Addresses

Physical addresses used for local frame delivery.

Data Link Protocol

Protocol determined by logical topology and physical media.

Ethernet

Common data link protocol for local area networks.

802.11 Wireless

Wireless networking standard for local area networks.

Point-to-Point Protocol (PPP)

Protocol for direct connection between two nodes.

High-Level Data Link Control (HDLC)

Bit-oriented protocol for point-to-point and multipoint links.

Frame-Relay

Packet-switching protocol for connecting local area networks.

LLC Sublayer

Identifies network layer protocol for data frames.

MAC Sublayer

Handles data encapsulation and media access control.

Ethernet Frame

Structure used to encapsulate data in Ethernet.

Ethernet Addressing

Includes source and destination MAC addresses.

Frame Check Sequence (FCS)

Trailer used for error detection in Ethernet frames.

IEEE 802.3 MAC

Specifications for Ethernet communications standards.

Half-Duplex Medium

Shared medium allowing one-way data transmission at a time.

CSMA/CD

Carrier Sense Multiple Access with Collision Detection method.

Full-Duplex Communication

Simultaneous two-way data transmission using Ethernet switches.

Minimum Ethernet Frame Size

64 bytes; frames below this are discarded.

Maximum Ethernet Frame Size

1518 bytes; frames above this are jumbo frames.

Jumbo Frames

Frames larger than 1500 bytes, supported by modern switches.

Ethernet MAC Address

48-bit address for device identification in Ethernet.

Hexadecimal Representation

MAC addresses expressed using 12 hexadecimal digits.

OUI Code

Organizationally Unique Identifier in MAC addresses.

Frame Processing

Examining MAC addresses for frame forwarding decisions.

Broadcast MAC Address

Address allowing frame delivery to all devices in LAN.

Unicast MAC Address

Unique address for single device communication.

Address Resolution Protocol (ARP)

Determines destination MAC for IPv4 addresses.

Neighbor Discovery (ND)

Determines destination MAC for IPv6 addresses.

Broadcast MAC Address

Address for sending frames to all devices.

FF-FF-FF-FF-FF-FF

Hexadecimal for Ethernet broadcast MAC address.

Multicast MAC Address

Address for communication with a group of devices.

01-00-5E

MAC address for IPv4 multicast packets.

33-33

MAC address for IPv6 multicast packets.

MAC Address Table

Stores MAC addresses for forwarding decisions.

Content Addressable Memory (CAM)

Another term for MAC address table.

Layer 2 Ethernet Switch

Uses MAC addresses for frame forwarding.

Ethernet Hub

Repeats bits to all ports except incoming.

Source MAC Address Learning

Switch learns addresses from incoming frames.

Refresh Timer

Default 5 minutes for MAC address entries.

Unknown Unicast

Forwarding when destination MAC is not in table.

Filtering Frames

Switch forwards frames based on MAC address table.

Store-and-Forward Switching

Receives entire frame, checks CRC before forwarding.

Cut-Through Switching

Forwards frame before complete reception.

Frame Forwarding Methods

Techniques for processing and sending frames.

Destination MAC Address Match

Switch forwards frame if address is in table.

Incoming Port

Port where a frame enters the switch.

Encapsulated Data

Data contained within a network frame.

Cut-through switching

Switch forwards data after reading destination MAC address.

Fast-forward switching

Lowest latency; forwards immediately after destination read.

Fragment-free switching

Checks first 64 bytes for errors before forwarding.

Memory buffering

Stores frames before forwarding during congestion.

Duplex settings

Configuration for simultaneous data transmission capabilities.

Full-duplex

Both ends can send and receive simultaneously.

Half-duplex

Only one end can send at a time.

Autonegotiation

Automatically negotiates speed and duplex settings between devices.

Auto-MDIX

Automatically detects cable type for device connections.

Ethernet switch

Device that forwards frames based on MAC addresses.

Destination MAC address

Unique identifier for network interface in a frame.