NetworkingA+

Network Hardware for CompTIA A+ 220-1101

Network hardware knowledge is required for CompTIA A+ 220-1101 — technicians must identify and understand routers, switches, access points, modems, firewalls, and other devices used in home and small business networks. Unlike the Network+ exam, A+ focuses on recognizing devices, understanding their roles, and performing basic configuration rather than deep protocol knowledge.

7 min

2 sections · 7 exam key points

1 practice questions

Core Network Devices

Router: connects multiple networks (typically the home network to the internet). Routes packets between networks based on IP addresses. Home routers typically combine router, switch, wireless AP, and firewall in one device. The default gateway IP is the router's LAN-facing IP. WAN port connects to the modem/ISP; LAN ports connect to internal devices.

Switch: connects multiple devices within the same network (same subnet). Operates at Layer 2 (MAC addresses) — forwards frames only to the correct port based on the destination MAC. Unmanaged switch: plug and play, no configuration. Managed switch: configurable VLANs, port mirroring, STP — requires expertise. Home and SOHO environments typically use unmanaged switches.

Hub: legacy Layer 1 device — broadcasts all traffic to all ports regardless of destination MAC. Creates a single collision domain — all devices compete for bandwidth. Completely replaced by switches in modern networks. You may still see hubs referenced on the exam for historical context.

Wireless Access Point (WAP): provides Wi-Fi connectivity. In homes, the router includes a built-in AP. Enterprise environments use separate APs managed by a wireless controller. Access points connect to the wired network via Ethernet and bridge wireless clients into the wired LAN.

Specialized Network Devices

Modem: MOdulates/DEModulates signal between digital (computer) and analog (telephone line) or specific (cable, fiber) transmission. DSL modem: connects to phone line, modulates data over POTS. Cable modem: connects to cable TV coaxial, uses DOCSIS standard. Fiber ONT (Optical Network Terminal): connects fiber from ISP to your home network — converts optical signal to Ethernet. Modern ISP equipment often combines modem + router in one unit.

Firewall: filters network traffic based on rules — allows or blocks based on IP address, port, protocol. Hardware firewall: standalone device or built into router — protects the entire network. Software firewall: installed on individual computers (Windows Defender Firewall) — protects that device. SOHO routers include a basic NAT firewall (blocks unsolicited inbound connections). Next-generation firewalls (NGFW) add application awareness, IPS, and content filtering.

PoE switch (Power over Ethernet): delivers power to connected devices through the Ethernet cable — eliminates separate power adapter. Used for: IP phones, wireless access points, security cameras, VoIP devices. 802.3af (PoE): 15.4W per port. 802.3at (PoE+): 30W per port. 802.3bt (PoE++): up to 100W. Verify total PoE budget of switch before adding many PoE devices.

Patch panel: passive device in a wiring closet that aggregates cable terminations — cables from wall jacks terminate on the back, patch cables connect to the switch on the front. Protects switch ports from constant cable changes. Cable certifier/toner/probe used for identifying which wall jack connects to which patch panel port.

Key exam facts — A+

Router: connects different networks (LAN to internet), routes by IP address
Switch: connects devices within the same network, forwards by MAC address (Layer 2)
Hub: broadcasts to all ports — replaced by switches; creates shared collision domain
WAP: bridges wireless clients to wired network; home routers include built-in AP
Modem: converts between digital and analog/optical signal — DSL, cable, fiber ONT
PoE switch: delivers power over Ethernet cable — 802.3af (15W), 802.3at (30W), 802.3bt (100W)
Firewall: hardware (protects network) vs software (protects individual device)

Common exam traps

A switch and a hub do the same thing

A switch learns MAC addresses and forwards frames only to the correct port — efficient, full-duplex. A hub broadcasts every frame to every port — inefficient, half-duplex, creates collisions. A 24-port switch provides 24 separate collision domains; a 24-port hub creates one large collision domain shared by all 24 devices. Hubs are obsolete; always use switches

Practice questions — Network Hardware

These questions are representative of what you will see on A+ exams. The correct answer and explanation are shown immediately below each question.

Q1.A technician needs to install a wireless access point in a location where running a power outlet would require extensive electrical work. What network hardware feature eliminates the need for a separate power outlet?

A.Fiber optic uplink

B.Power over Ethernet (PoE) switch

C.Unmanaged switch

D.Wireless repeater

Explanation: Power over Ethernet (PoE) delivers electrical power through the standard Ethernet cable, eliminating the need for a separate power outlet at the AP location. As long as the switch supports PoE (802.3af for most APs, 802.3at for higher-power APs) and the AP is PoE-compatible, a single Cat5e/6 cable provides both data connectivity and power. This is the primary reason enterprise APs are PoE-powered — flexible placement without electrical constraints.

Frequently asked questions — Network Hardware

What is the difference between a router and a switch?

A router connects different networks together (your home LAN to the internet) and makes forwarding decisions based on IP addresses (Layer 3). A switch connects multiple devices within the same network and forwards frames based on MAC addresses (Layer 2). In a home network: the router provides the connection to the ISP and assigns IPs via DHCP; the switch (often built into the router) provides multiple wired connection ports for devices on the same local network. Without a router, your devices can talk to each other but not reach the internet.

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