Core Networking Appliances
Networking appliances, applications, and functions
What you will learn
- Distinguish a switch's job from a router's job in one sentence each.
- Explain when you need a firewall rather than just a switch or router.
- Tell a wireless access point apart from a combined home router.
- Pick the correct device for a given scenario without confusing their roles.
Most exam questions on this topic are a short scenario: "an organization wants to do X — which device?" The trick isn't memorizing each device's definition, it's knowing the boundary between them: a switch connects devices within the same network, a router connects different networks, and a firewall controls what's allowed to cross between them.
Switch vs. Router
| Switch | Router | |
|---|---|---|
| Layer | Layer 2 (primarily) | Layer 3 |
| Operates on | MAC addresses | IP addresses |
| Connects | Devices within the same local network | Different networks to each other (e.g., LAN to the internet) |
| Example decision | Adding 20 desktop devices on the same floor | Connecting two offices in different cities |
Other common devices
| Firewall | Inspects traffic and decides what's allowed through, based on rules (port, address, protocol). |
|---|---|
| Access Point (AP) | Provides wireless connectivity and bridges it to the existing wired network — doesn't route between networks by itself normally. |
| Load Balancer | Distributes requests across multiple servers to avoid overloading a single one. |
| Proxy | Sits between client and server — hides the client's address, filters content, or caches it. |
Applied scenario
A small office wants to let the sales team reach the internet, block access to file-sharing sites, and connect 15 computers to share a printer. It needs: a switch (to connect the 15 computers), a router (for internet access), and a firewall (to block specific sites) — often combined into one box in small offices, but the functions are logically completely separate, and the exam tests them that way.
What matters on the exam
- "Connect devices on the same network" = switch. "Connect two networks" = router.
- A firewall decides "what's allowed," not "how to get there" — a key difference from a router.
Quick check
Answer in your head first, then reveal.
Which device connects 20 computers on the same floor?Reveal the answer
A switch.
Which device connects two offices in different cities?Reveal the answer
A router.
Which device decides to allow or block traffic based on rules?Reveal the answer
A firewall.
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Your next step
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Sources
Used to verify the facts. The writing is original to Passuit.