CCNA 200-301 Day 0

What is a Network? Course: NetworkChuck's Free CCNA 200-301 (YouTube) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

WHAT IS A NETWORK?

A network is simply two or more devices connected together to share data. That's it. The internet itself is just thousands of routers chained together, passing your data from point A to point B in milliseconds.

HOW DATA TRAVELS — THE CALL OF DUTY EXAMPLE

When you shoot someone in an online game, your data doesn't magically appear on their screen. It physically travels through a chain of devices:

Your PS4 → Ethernet Cable → Switch → Router → Firewall → Modem → ISP → Internet (router hops) → Game Server → Internet → Their Modem → Their Router → Their PS4

Every single device in that chain is what you will learn to configure in the CCNA.

CORE NETWORK DEVICES

Switch — Connects multiple devices within the same network — Uses MAC addresses to identify devices — Think of it as a power strip for your network — Does NOT send traffic to the internet, only within your local network

Router — Connects different networks together — Uses IP addresses to route traffic — Think of it as a post office — it decides where to send each packet — Your home router connects your local network to the internet

Firewall — Protects your network by blocking bad traffic and allowing good traffic — Think of it as a security guard checking everyone entering and leaving — Hackers are always scanning networks — the firewall keeps them out

Wireless Access Point (WAP) — Creates a Wi-Fi signal so devices can connect without cables — Think of it as a radio tower for your local network — In homes, this is usually built into your router/modem box

Modem — Translates your network signal into a format your ISP can carry — Think of it as a language translator between your home and your ISP

LAN vs WAN

LAN (Local Area Network) — Your home or office network — Fast speeds (Gigabit range) — You own and control it — Example: everything connected to your home Wi-Fi

WAN (Wide Area Network) — Covers large distances — cities, countries, the entire world — The Internet is the biggest WAN that exists — Owned by ISPs and telecom companies — Example: PTCL, Jazz, Stormfiber connecting you to the world

HOME NETWORK vs ENTERPRISE NETWORK

Home: One all-in-one box handles modem + router + switch + firewall + Wi-Fi Enterprise: Every function gets its own dedicated hardware device

Why does this matter? The CCNA teaches you enterprise-level networking — separate devices, real configurations, and Cisco's command line interface (CLI). That's what you'll use on the job.

KEY TERMS

MAC Address — Hardware ID burned into a device, used by switches IP Address — Software address assigned to a device, used by routers Default Gateway — Your router's IP address; where your traffic goes when leaving your network Routing Table — A map inside a router listing all known networks and how to reach them Packet — A small chunk of data traveling across the network ISP — Internet Service Provider (PTCL, Jazz, Stormfiber, etc.) Packet Tracer — Free Cisco simulator used to practice CCNA labs

WHAT IS THE CCNA?

The Cisco Certified Network Associate (200-301) is the #1 entry-level networking certification in the IT industry. It covers switching, routing, firewalls, wireless, security, and automation. It's the certification that gets you hired as a Network Engineer — the person who builds and maintains all the infrastructure shown above.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Source: NetworkChuck Free CCNA — Day 0 | Notes by Kareem