Networking Commands and Concepts

DHCP (Dynamic Host Configuration Protocol):

• It is a network protocol that automates IP address assignment to devices on a network.

Network Commands:

ping

• Meaning (Simple): “Hey, are you there?” It’s used to check if another computer, server, or website is currently online and reachable from your PC.
• Technical Meaning: ping sends ICMP (Internet Control Message Protocol) Echo Request packets to a target host.
  • If a reply is received, the host is “alive”.
  • Otherwise, its blocked.
• Syntax: ping website_address
  • Example: ping google.com
  • To Exit: Press Ctrl + C in the command prompt/terminal.
• Loopback Address (127.0.0.1):
  • This IP always refers to “yourself” – your own computer.
  • It’s used to test the network configuration of your local PC.
  • Example: Like sending a letter to your own house to test if your mailbox works.

traceroute (Windows: tracert)

• It shows the exact path your data takes from your computer to a website or server, revealing every “hop” (router) along the way. Each hop represents a router that the data packet passes through.
• Syntax: traceroute <hostname_or_IP_address> (on macOS/Linux) or tracert <hostname_or_IP_address> (on Windows)
• *** (Asterisks) in Output: It indicates that the router at that hop did not reply.

ipconfig (Windows) / ifconfig (macOS/Linux)

• ipconfig (Windows):
  • Shows the IP address, subnet mask, default gateway, DNS servers, and other network settings that your Windows computer is currently using.
• ifconfig (macOS/Linux):
  • Provides:

Term	Represents
inet	IP address
netmask	Network range
lo0	Loopback
broadcast	Address used to send messages to all devices.

Ethernet:

It is used to connect devices with a physical cable so that they can communicate or access.

• How it Works:
  1. Plug one end of an Ethernet cable into your PC’s network port.
  2. Plug the other end of the cable into a modem or router.
  3. Your PC can now communicate over the network and access the internet.

Ethernet vs. Wi-Fi:

Feature	Ethernet	Wi-Fi
Signal	Through cable (copper, fiber)	Through air (radio waves)
Speed	faster	Varies, can be slower than wired
Stability	More stable	Can be affected by walls, distance.
Security	More secure	Less secure
Mobility	No (wired)	Yes (moves freely)

Comparison of Network Types

Network Type	Definition	Type
Ethernet	A specific wired technology for local area networking.	LAN Technology (Wired)
Wi-Fi	A specific wireless technology for local area networking.	LAN Technology (Wireless)
LAN	A network connecting devices within a limited area (e.g., home, office).	Local Network
WAN	A network that spans a large geographical area, often connecting multiple LANs.	Wide Network
Internet	A global system of interconnected networks using the Internet Protocol (IP) suite.	Global WAN