Networking Concepts Quiz

Networking for DevOps

• Networking is a system of interconnected computers and devices that communicate with each other.
• Networks are used for communication between devices, enabling multiple users to share devices (like music, video, printers, scanners), and creating the Internet.
• Different types of networks include Local Area Networks (LANs), Metropolitan Area Networks (MANs), and Wide Area Networks (WANs) - with specialized networks like SONET used in submarines.

Network Components

• Switch: Connects two or more computers.
• Router: Connects networks together.
• Modem: For modulation and demodulation to convert signals
• Hub: A power extension device that broadcasts signals to its connected devices.
• NIC (Network Interface Card): Connects a computer to a network; has a MAC (Media Access Control) address - now often preinstalled on motherboards.
• Bridge: Connects multiple LANs; now obsolete

Protocols

• A network protocol is a set of rules for how data is transmitted between devices on a network.
• Examples include HTTP, TCP, IP, FTP, SMTP, etc.

IP Addresses

• An IP address is a unique number assigned to each device on a network to allow communication.
• IPv4 is a 32-bit address written as four numbers separated by dots (e.g., 123.89.46.72). It has a limited number of addresses (about 4.3 billion).
• IPv6 is a 128-bit address written in eight groups of hexadecimal numbers (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). It provides a vastly larger pool of addresses than IPv4.

IP Address Classes

• A network protocol is used to divide IP addresses into classes (A, B, C) based on the starting numbers; these determine their use in networks.
• Class A: Large networks.
• Class B: Medium-sized networks.
• Class C: Small networks.
• Some ranges of IP addresses are reserved for special purposes

Public and Private IP Addresses

• Public IP: Used to identify devices on the internet. Assigned by ISPs and accessible globally.
• Private IP: Limited to private networks (home or office). Not accessible from the internet.

Static and Dynamic IP Addresses

• Static IP: Manually assigned and doesn't change.
• Dynamic IP: Automatically assigned by a DHCP server and can change periodically.

Loopback Address

• 127.0.0.1 is commonly known as "localhost"

Network ID and Host ID

• IP addresses are divided into network ID and host ID.
• The network ID part differs based on the IP class (A, B, or C) and identifies the network the device belongs to
• Devices with the same network ID can connect directly, while those with different network IDs need a router to connect.

Subnetting

• Divides a network into smaller, more manageable segments. Useful for enhancing security and network performance.
• Used with subnet masks to allocate network and host portions.

OSI Reference Model

• A conceptual model that describes how network communication works.
• Consists of seven layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

TCP/IP Model

• A simplified four-layer version of the OSI model that is commonly used in the internet and networking infrastructure.
• It includes four layers: Application, Transport, Internet, and Network Interface (which combines the OSI's Data Link and Physical layers).

Protocols and Port Numbers

• Protocols and port numbers are used in network communication to specify different services and applications.

Network Troubleshooting Tools

• Tools like ping, traceroute, telnet, curl, dig, and netstat are used to diagnose, troubleshoot, and manage network issues.