Networking Basics — Ethical Hacking as a Beginner [03]

Now that we have set up our Virtual Machine with Kali installed, let us understand some theory which will prove to be helpful very soon.

Networking Basics for Ethical Hacking

It’s time to dive into a super important foundation of hacking: networking. Think of it like understanding the roads and highways that information travels on.

Protocols: The Rules of the Network Road

TCP/IP: The king of networking. It’s a suite of protocols that dictate how devices talk to each other on the internet.

• TCP (Transmission Control Protocol): Reliable delivery, like a package with tracking and a signature.
• IP (Internet Protocol): Think of it like the address system, getting packets to the right place.

UDP (User Datagram Protocol): Fast and simple, like a postcard — gets the message there quick, but no guarantee it arrives or arrives on time.

HTTP (HyperText Transfer Protocol): The language of the web! Your browser uses it to ask for websites.

DNS (Domain Name System): Like a giant phonebook. Turns domain names (google.com) into IP addresses computers understand.

IP Addresses: Your Device’s Location

• Every machine on a network has its own IP address (like 192.168.1.10).
• Private IP Addresses: Used inside your home or office network. Devices on your local network use these to talk to each other.
• Public IP Address: This is the address your router has facing the wider internet. All outgoing traffic from your home seems to come from this single address.
• IPv4: The older standard, you’ve likely seen these.
• IPv6: The newer version. Looks crazier, but we need it because we’re running out of IPv4 addresses!

The OSI Model: A Map of Communication

This isn’t something you use daily, but it helps understand how networks work in layers:

1. Physical: The actual cables and signals
2. Data Link: Think Ethernet frames and MAC addresses
3. Network: IP addresses and routing here
4. Transport: TCP and UDP live here
5. Session: Maintaining connections
6. Presentation: Data stuff (like encryption)
7. Application: The programs you actually use

Other Important Things

• Ports: Like apartment numbers on an IP address. Different services use different ports.
• NAT (Network Address Translation): How your home router lets multiple devices share one public IP.
• Firewalls: Security guards that block or allow traffic based on rules.
• TLS: Transport Layer Security
• ttl — time to live

TCP 3 — way handshake process:

• Client sends SYN (synchronization) flag to server
• Server responds with SYN/ACK (acknowledge) flag
• Client responds again with ACK flag

Why Hackers Need to Know This

• Finding Targets: You need to understand how devices are addressed to scan them.
• Exploiting Vulnerabilities: Many attacks target specific protocols or services on specific ports.
• Staying Undetected: Understanding how networks work lets you cover your tracks better.

We’re just starting out, expect more amazing information on this journey.