2.1 – Ports and Protocols: Introduction to IP

The internet protocol (IP) is like a moving truck for your data. It carries your data across the network, but it doesn't know what's inside the data.

A data packet is like a box that holds your data. This data can be application-specific, like a webpage or email message.

Network protocols allow computers to communicate effectively. They are like rules that govern how data is sent and received across a network.

The network, like internet cable, is the road on which data is transported.

Encapsulation is the process of packaging data within multiple layers of information.

The ethernet header and trailer are like the front and back of the box containing your data.

The ethernet payload is the data itself, like the contents inside the box. It can contain various types of data, including IP packets.

Different devices on a network, such as computers, smartphones, or servers, are like different houses in a neighborhood.

The process of scanning a server to identify open ports and determine the services running on them.

Designated numerical values used to identify specific applications or services running on a network device, such as a server.

A standard communication protocol that ensures reliable delivery of data over the internet.

A communication protocol that prioritizes speed over reliability, making it suitable for applications like audio and video streaming.

A well-established port number used for a specific service, like port 80 for HTTP web traffic.

A random port number assigned to a communication session by a client device.

The process of assigning a specific port number to a communication session, allowing the server to identify the intended recipient.

The use of both IP addresses and port numbers to uniquely identify communication pathways between devices on a network.

Simultaneous communication over multiple ports from a single client device to a single server, utilizing different protocols and port numbers.

The use of a port scanner to analyze a server and identify its open ports, revealing potential security vulnerabilities.

A unique address assigned to each computer within a network, similar to a physical house address.

A protocol that manages the process of delivering data packets from one IP address to another, akin to a delivery truck transferring packages.

A well-known port number used by a specific service, like a web server, that remains consistent across different devices.

A port number assigned temporarily and used for a particular communication session, often changing after the session ends.

The process of directing incoming data packets to the correct application based on their port number, like sorting mail to different rooms in a house.

A protocol used to exchange data between two points over a network, similar to a conversation between two people.

A server running a specific application on a well-known port number, like a web server listening on port 80.

A device that sends data requests to a server, similar to a person making a request.

The transfer of information in the form of packets from one computer to another, similar to sending a package through the mail.

The communication of data between a client and a server, involving both sending and receiving data.

Standard port numbers used by common services, like port 80 for HTTP, making them easily recognizable by devices.

A mechanism used to enable communication between a client and a server, ensuring that the correct application receives the data.

Port numbers are not designed to prevent unauthorized access to services, but simply as a means of identifying them.

The use of dynamic port numbers that can change with each communication session, offering flexibility and potentially increasing security.

TCP ensures that data sent from one device is confirmed as received by the other device. It manages retransmissions if packets are lost and can reorder packets that arrive out of order.

TCP regulates the speed of data transmission to prevent a device from being overwhelmed. It allows a device to tell the sender to slow down if it's receiving data faster than it can process.

UDP sends data without checking if it is successfully received. It's fast but doesn't have the features of TCP like retransmissions or reordering.

UDP focuses on speed and does not have flow control like TCP. It prioritizes delivering data as quickly as possible, even if it means some packets might get lost.

The act of wrapping data packets in a header containing information about the packet is called encapsulation. TCP and UDP packets are encapsulated within IP packets.

The Hypertext Transfer Protocol Secure (HTTPS) uses TCP to establish a secure connection for transmitting web data. It ensures data privacy and integrity.

Secure Shell (SSH) uses TCP to create an encrypted terminal connection between devices, enabling secure remote command execution and file transfers.

Real-time communication refers to applications that require immediate data delivery, such as voice calls or video conferencing. UDP is often preferred in these scenarios because of its speed.

Applications like DHCP and TFTP are responsible for handling potential data loss due to UDP's unreliable nature. They have mechanisms to resend lost information if needed.