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A+ Core 1 · CompTIA 220-1201 V15 · Objective 2.5

Compare and contrast common networking hardware devices

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Objective 2.5: Compare and contrast common networking hardware devices

Cert: CompTIA A+ Core 1 (220-1201) V15 Domain: 2.0 Networking Weight: ~23% of Core 1 Depth: Compare and contrast. Recognize the devices and know what each does.

What this objective tests

You should be able to identify and explain the common networking hardware devices found in offices and homes: routers, switches, access points, patch panels, firewalls, PoE devices, modems (cable, DSL, fiber ONT), and NICs.

Key facts

Router:

  • Forwards packets between networks (e.g., LAN to internet). Operates at Layer 3 (network).
  • Maintains routing tables and selects the best path.
  • Home/SOHO routers are integrated devices: router + switch + access point + firewall in one box.

Switch:

  • Forwards frames between devices on the same network. Operates at Layer 2 (data link), some also at Layer 3.
  • Each switch port is its own collision domain.
  • Managed switch. Configurable via web/CLI. Supports VLANs, port security, QoS, link aggregation, SNMP monitoring.
  • Unmanaged switch. Plug-and-play, no configuration. Cheap, simple, fine for very small networks.

Access point (AP):

  • Provides Wi-Fi connectivity on a wired network. Bridges wireless clients to the wired Ethernet.
  • Standalone APs are often controller-managed in enterprise (controller-based or cloud-managed).
  • Multiple APs broadcasting the same SSID let clients roam between them.

Patch panel:

  • A physical termination point for cable runs (typically RJ45 in office environments).
  • Cables from desks and other endpoints terminate in the patch panel. Short patch cables connect the patch panel to switch ports.
  • Makes cable management cleaner and protects the long cable runs from wear.

Firewall:

  • Controls traffic between networks based on rules.
  • Stateful firewall. Tracks active connections and allows return traffic for established sessions.
  • Next-generation firewall (NGFW). Adds application awareness, IPS, malware detection, user identity, and other Layer 7 features.

Power over Ethernet (PoE):

  • Delivers electrical power over the same Ethernet cable that carries data. Powers IP phones, APs, cameras, and other low-power devices.
  • Injector. A device that adds PoE to an Ethernet line between a non-PoE switch and a PoE device. Useful for one-off PoE needs.
  • PoE switch. A switch with PoE-capable ports. Standard in environments with many PoE devices.
  • PoE standards. 802.3af (PoE, ~15W per port), 802.3at (PoE+, ~30W), 802.3bt (PoE++, up to ~90W). Devices must be matched to switches that support enough wattage.

Cable modem:

  • Connects an ISP's coaxial cable network to the customer's network.
  • Provides one Ethernet handoff (sometimes with built-in router/Wi-Fi for ISP-supplied units).

DSL (Digital Subscriber Line):

  • Internet over telephone lines. Slower than cable in most areas but available where cable infrastructure is not.
  • Modem terminates the DSL signal and provides Ethernet.

ONT (Optical Network Terminal):

  • Converts fiber-optic signals from the ISP into Ethernet for the customer's network.
  • Used by fiber-to-the-home (FTTH) services like Verizon Fios, AT&T Fiber, Google Fiber.

NIC (Network Interface Card):

  • The physical (or virtual) network adapter in a device.
  • MAC address (Media Access Control). A 48-bit hardware address burned into the NIC, displayed as six pairs of hex digits (e.g., 00:1A:2B:3C:4D:5E). Globally unique. Used at Layer 2 for local network addressing.

Common gotchas

  • Router vs switch confusion. A router connects networks. A switch connects devices within a network. Home "routers" are actually combination devices.
  • Managed vs unmanaged switch needs. Most homes and very small offices do fine with unmanaged. Anything that needs VLANs, SNMP, or controlled port access needs managed.
  • PoE wattage budget. A 24-port PoE switch may have a total PoE budget far less than 24 ports x maximum wattage. Plan total power, not per-port maximum.
  • PoE vs PoE+ vs PoE++. Cameras with PTZ, lighting, or other power-hungry features may require PoE++ that a regular PoE switch cannot provide.
  • Cable modem vs ONT. Cable modems use coaxial; ONTs use fiber. Different physical media, different devices. Customers sometimes get confused when transitioning between services.
  • NIC duplex mismatch. Auto-negotiation usually works, but if one side is set to manual full duplex and the other to manual half duplex, you get serious packet loss and slow throughput. Always check.
  • Default firewall deny-all. Stateful firewalls usually deny everything inbound and allow established outbound by default. Adding services without explicit allow rules will not work.

Real-world context

For a typical SMB office Revtek deploys:

  • ISP-provided modem (cable, fiber ONT, or DSL).
  • Business firewall (often a Fortinet, Cisco Meraki, Ubiquiti, or similar).
  • Managed PoE switch(es) for desk Ethernet plus APs and IP phones.
  • 1-3 access points placed for coverage.
  • Patch panel and structured cabling for a clean wiring closet.

Common helpdesk hardware-device calls:

  • "Internet is out." First check is the modem or ONT (lights and link status). Then the firewall. Then the LAN.
  • "My phone keeps rebooting." Usually a PoE wattage or switch port issue.
  • "New AP added; clients can't join." Check the switch port (PoE, VLAN, trunking) and the controller configuration.

Sources

  • [CompTIA A+ 220-1201 Exam Objectives Version 4.0, Section 2.5](../../../../../../30-RevyTechJourney/CompTIA%20A%2B%20220-1201%20Exam%20Objectives%20%284.0%29.pdf)
  • [Wikipedia: Router (computing)](https://en.wikipedia.org/wiki/Router_(computing))
  • [Wikipedia: Network switch](https://en.wikipedia.org/wiki/Network_switch)
  • [Wikipedia: Power over Ethernet](https://en.wikipedia.org/wiki/Power_over_Ethernet)
  • [Wikipedia: Optical network terminal](https://en.wikipedia.org/wiki/Optical_network_terminal)
  • [Wikipedia: MAC address](https://en.wikipedia.org/wiki/MAC_address)