CCNA - MOD5,6,7

Positional notation

means that a digit represents different values depending on the "position" the digit occupies in the sequence of numbers.

Hexadecimal

is a base sixteen numbering system, using the digits 0 through 9 and letters A to F.

IPv6

are 128 bits in length.

Binary

is a base two numbering system that consists of the numbers 0 and 1, called bits

Decimal

is a base ten numbering system that consists of the numbers 0 through 9

Binary

is what hosts, servers, and networking equipment uses to identify each other.

Data Link Layer

is responsible for communications between end-device network interface cards.

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

Data Link layer consist of two types

Logical Link Control (LLC) IEEE 802.2

communicates between the networking software at the upper layers and the device hardware at the lower layers. Places information in the frame to identify which network layer protocol is used for the frame.

Media Access Control (MAC). IEEE 802.3, 802.11, or 802.15

is responsible for data encapsulation and media access control.

Physical Topology

shows physical connections and how devices are interconnected.

Logical topology

identifies the virtual connections between devices using device interfaces and IP addressing schemes.

Point-to-point

the simplest and most common WAN topology. Consists of a permanent link between two endpoints.

Hub and spoke

similar to a star topology where a central site interconnects branch sites through point-to-point links

Mesh

- provides high availability but requires every end system to be connected to every other end system.

Bus

All end systems chained together and terminated on each end.

Ring

Each end system is connected to its respective neighbors to form a ring.

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.

Controlled Access

Deterministic access where each node has its own time on the medium.

Contention-based access

All nodes operating in half-duplex, competing for use of the medium.

CSMA/CD

Used by legacy Ethernet LANs. Operates in half-duplex mode where only one device sends or receives at a time

CSMA/CA

Used by IEEE 802.11 WLANs. Operates in half-duplex mode where only one device sends or receives at a time.

Layer 2 Addresses

Also referred to as a physical address.

point-to-point, hub and spoke, and mesh

Three common types of physical WAN topologies are:

Data link addresses

are also known as physical addresses.

Ethernet frame

This is the internal structure of the Ethernet frame.

Ethernet Addressing

1.The Ethernet frame includes both a source and destination MAC address to deliver the Ethernet frame from Ethernet NIC to Ethernet NIC on the same LAN.

Ethernet Error detection

The Ethernet frame includes a frame check sequence (FCS) trailer used for error detection.

"collision fragment" or "runt frame"

Any frame less than 64 bytes in length is considered a ___________.

"jumbo" or "baby giant frames"

Frames with more than 1500 bytes of data are considered

Ethernet MAC address

this address consists of a 48-bit binary value, expressed using 12 hexadecimal values.

Unicast MAC Address

•is the unique address that is used when a frame is sent from a single transmitting device to a single destination device.

Ethernet broadcast frame

is received and processed by every device on the Ethernet LAN.

Ethernet multicast frame

is received and processed by a group of devices that belong to the same multicast group.

Ethernet switch

It examines its MAC address table to make a forwarding decision for each frame, unlike legacy Ethernet hubs that repeat bits out all ports except the incoming port.

Layer 2 Ethernet Switch

It uses Layer 2 MAC addresses to make forwarding decisions.

Store-and-Forward Switching

This frame forwarding method receives the entire frame and computes the CRC.

Cut-Through Switching

This frame forwarding method forwards the frame before it is entirely received

Fast-forward switching

Offers the lowest level of latency by immediately forwarding a packet after reading the destination address

Fragment-Free Switching

A compromise between the high latency and high integrity of store-and-forward switching and the low latency and reduced integrity of fast-forward switching, the switch stores and performs an error check on the first 64 bytes of the frame before forwarding

Full Duplex

•- Both ends of the connection can send and receive simultaneously.

Half Duplex

•Only one end of the connection can send at a time.

•organizationally unique identifier (OUI).

all vendors that sell Ethernet devices must register with the IEEE to obtain a unique 6 hexadecimal (i.e., 24-bit or 3-byte) code called ___________________________

Address Resolution Protocol (ARP).

The process that a source host uses to determine the destination MAC address associated with an IPv4 address is known as _________________.

•Neighbor Discovery (ND).

The process that a source host uses to determine the destination MAC address associated with an IPv6 address is known as ___________________

Auto-MDIX

Connections between devices once required the use of either a crossover or straight-through cable.