Networking Fundamentals
IP Addresses
An IP (Internet Protocol) address is a unique numerical label assigned to every device connected to a network.
- IPv4: (e.g.,
192.168.1.10) - IPv6: (e.g.,
fe80::...) - Loopback Address (localhost):
127.0.0.1(used for communication within the local machine).
Ports
Ports are communication endpoints used by software applications to communicate over a network. A port is a number between 1 and 65535.
| Port | Purpose |
|---|---|
| 22 | SSH (Secure Shell) |
| 80 | HTTP (Web Traffic) |
| 443 | HTTPS (Secure Web Traffic) |
| 21 | FTP (File Transfer Protocol) |
DNS (Domain Name System)
DNS translates human-readable domain names (like google.com) into numerical IP addresses. Linux systems use the file /etc/resolv.conf to list DNS servers.