Chapter 1

A seven-layer model that helps understand and troubleshoot networks by organizing their functions.

The wrapping of data with additional information at each layer of the OSI model.

The physical or logical arrangement of devices in a network.

Different categories of networks based on their size, geography, and ownership.

Using the OSI model to identify the layer where a network problem originates.

Anything that can be shared on a network, such as files, web pages, printers,and cameras.

A model where a client requests resources from a server.

A common language for describing specific network functions, aided by the OSI model.

A simplified representation of a complex network, highlighting essential components and functions.

A simplified representation of something real, highlighting key features and ignoring unnecessary details.

The process of reducing a network's complexity to create a usable representation.

An essential component of a network or system that the model must include for accuracy.

The model's ability to represent the critical functions of an actual network, retaining its usefulness.

The many interconnected components and operations within a network that demand simplified representation.

Using computers to simulate and foresee events, such as predicting weather patterns.

A model airplane that omits functionality of a working aircraft, but keeps essential parts, like the wings and body

A switch forwards frames only to the destination MAC address, while a hub sends frames to all connected devices.

A 4-byte checksum at the end of a frame used to verify data integrity during transmission.

The CRC is a mathematical technique used to calculate the FCS, ensuring data accuracy.

A Network Interface Card (NIC) handles the physical transmission and reception of data frames.

FF-FF-FF-FF-FF-FF is the MAC address used to send a frame to every device on a network.

A broadcast at the data link layer (Layer 2) using the MAC address FF-FF-FF-FF-FF-FF.

How a sending NIC learns the MAC address of the destination NIC.

When a sending NIC doesn't know the destination MAC address, it uses the IP address to identify the target computer.

A unique identifier assigned to every network interface card (NIC), used to identify devices on a local network.

A network frame containing destination MAC address specifically for one device on the network.

A network frame containing destination MAC address that is sent to every device on the network.

The process of a sending system's NIC building a frame, adding data and FCS, including destination and source MAC addresses, and sending it through the cable.

The process of the receiving NIC receiving the frame, stripping off the framing information, and delivering the data to the operating system.

A switch forwards unicast frames to the specific destination MAC address and sends broadcast frames to all devices on the network.

A network interface card (NIC) operates at both the Physical and Data Link layers of the OSI model, handling frames and data transfer.

The NIC handles data moving in and out of the network cable connection, and also moves data between the NIC and the operating system.

An address used for routing data packets within a network, as opposed to the physical address (MAC address) of the network interface card.

A method used to represent IP addresses, comprising four 8-bit numbers (0-255) separated by periods, such as 192.168.1.1.

A unique physical address permanently assigned to a network interface card (NIC), used for communication within a local network.

IP addresses enable routers to forward data packets across different networks efficiently, using logical addressing instead of physical addressing.

The core protocol suite that governs communication over the internet, providing a framework for data transmission and addressing.

Robert E. Kahn and Vinton Cerf, two researchers at DARPA, developed the basic parameters of TCP/IP in the early 1970s.

Routers connect different subnets and use IP addresses to determine the best path for data packets, enabling communication across various networks.

The top layer of the OSI model responsible for communication between applications, handling data presentation, encryption, user authentication, and other application-specific functions. It doesn't directly refer to the applications themselves but to the code in operating systems that enables network-aware applications.

Application Programming Interface; a set of predefined routines, protocols, and tools that allow programmers to extend an application's capabilities by interacting with its core functionality.

A unit of data created by the Transport layer that includes information for the receiving host and the application it's intended for. It's later encapsulated by the Network layer.

Similar to a segment but created by the Transport layer in a connectionless network, where no pre-established connection exists. It's also encapsulated by the Network layer.

The result of encapsulating a segment or datagram with Network layer information, providing routing instructions for the data within the network. It's further encapsulated by the Data Link layer.

The complete data unit created by the Data Link layer, containing the packet, network headers, and additional information for error detection and transmission control. It's transmitted as bits and bytes over the network medium.

An application designed to use network resources and functions, such as web browsing, email, file sharing, and remote access. These programs utilize APIs provided by operating systems to interact with the network.

Both are units of data created by the Transport layer. A segment is used in connection-oriented networks, where a connection is established before data transmission. A datagram is used in connectionless networks, where data is sent without establishing a connection first.