Network Protocols and Network Operating Systems

Flashcards covering networking protocols, rules of communication, the OSI/TCP-IP models, data encapsulation, and Cisco IOS operating system basics.

Protocols

The rules that govern communication and the sending of messages between a source and a destination, whether face-to-face or over a network.

Encoding

The process of converting information into another, acceptable form for transmission.

Decoding

The process of reversing the encoding process in order to interpret the transmitted information.

Flow Control

A component of message timing that defines how much information can be sent and the speed at which it can be delivered.

Response Timeout

A protocol rule specifying how long a host should wait for responses and what action to take if a timeout occurs.

Access method

The rule that determines when someone or a device is allowed to send a message over the network.

Protocol suite

A group of inter-related protocols necessary to perform a communication function, implemented by hosts and networking devices in software or hardware.

TCP/IP suite

Specific suite of protocols required for transmitting and receiving information using the Internet.

ICANN

The Internet Corporation for Assigned Names and Numbers; coordinates IP address allocation, domain name management, and TCP/IP protocol identifiers.

IANA

The Internet Assigned Numbers Authority; responsible for overseeing and managing IP address allocation and protocol identifiers for ICANN.

OSI Model

A 7-layer networking model containing the Application, Presentation, Session, Transport, Network, Data Link, and Physical layers.

Application Layer (OSI)

Layer $7$ of the OSI model; contains protocols used for process-to-process communications.

Presentation Layer (OSI)

Layer $6$ of the OSI model; provides for common representation of the data transferred between application layer services.

Session Layer (OSI)

Layer $5$ of the OSI model; provides services to the presentation layer to organize its dialogue and manage data exchange.

Transport Layer (OSI)

Layer $4$ of the OSI model; defines services to segment, transfer, and reassemble data for individual communications between end devices.

Network Layer (OSI)

Layer $3$ of the OSI model; provides services to exchange individual pieces of data over the network between identified end devices using IP addresses.

Data Link Layer (OSI)

Layer $2$ of the OSI model; describes methods for exchanging data frames between devices over a common media.

Physical Layer (OSI)

Layer $1$ of the OSI model; describes the mechanical, electrical, functional, and procedural means to activate and maintain physical connections for bit transmission.

Segmentation

The process of dividing data into smaller, more manageable pieces to send over the network to increase reliability and prevent delays.

Multiplexing

The process used to interleave the pieces of separate conversations together on the network.

Protocol Data Unit (PDU)

The form that a piece of data takes at any layered model level; examples include Data, Segment, Packet, Frame, and Bits.

Encapsulation

The process where various protocols add information to application data at each level as it is passed down the protocol stack.

De-encapsulation

The process used by a receiving device to remove one or more protocol headers as data moves up the stack toward the end-user application.

MAC addresses

Media Access Control addresses; data link layer addresses responsible for delivering frames from one NIC to another on the same network.

Cisco IOS

The Internetwork Operating System; the network operating system used on Cisco infrastructure devices.

Kernel

The portion of the operating system that interacts directly with computer hardware.

Shell

The portion of the operating system that allows users to interact with the device via CLI or GUI.

Console port

A management port providing out-of-band access, which refers to a dedicated channel used for device maintenance purposes only.

SSH

Secure Shell; a protocol providing secure remote login through a virtual interface using encryption and stronger password authentication than Telnet.

User EXEC mode

A CLI mode which allows only a limited number of basic monitoring commands and is often referred to as view-only mode; prompt ends with "$>$".

Privileged EXEC mode

A CLI mode that allows all monitoring commands and execution of configuration/management commands; prompt ends with "#".

IP address (Manual Assignment)

Providing manual static assignments for end devices including IP address, Subnet mask, and Default gateway.

Switch Virtual Interface (SVI)

A virtual interface such as interface vlan $1$ used to provide an IP address to a switch for remote management.