220-1201 Networking Study Guide for the CompTIA A+ Core Series Exam

Networking Hardware Devices

Networking hardware includes the physical components used to achieve network connectivity. All active network hardware devices require a connection to some form of power source or supply. You must be able to compare and contrast common networking hardware.

Routers

A router is a device that connects multiple network devices and determines the best path for reaching a specified device using routing tables. Routers are OSI Layer 3 devices and make decisions based on logical addresses. Key functions of a router include connecting multiple network devices to one another, breaking up broadcast domains, and connecting one LAN to another LAN on a wide area network (WAN).

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Switches

A switch is an OSI Layer 2 device that examines the header of incoming packets for the MAC address and forwards the packet to the correct location. Switches can be managed or unmanaged.

Managed

A managed switch is one that allows for port configuration, traffic management, and traffic monitoring. Managed switches offer quality of service (QoS), redundancy, port mirroring, and VLANs.

Unmanaged

An unmanaged switch does not allow for configuration and passes on all data for a MAC address to its ports.

Access Point (AP)

An AP is technically any device to which a host can connect in order to access a network. Wired access points include hubs and switches. However, the term usually refers to a wireless access point (WAP) that allows Wi-Fi devices to connect to a network.

Patch Panel

A patch panel is a dumb device that is essentially a large rack-mounted centralization device whose sole purpose is to connect cables together. A dumb device is a device that broadcasts all data coming in through the input port out over all output ports. A dumb device, like a patch panel, makes no logical decisions and simply serves as a connection and relay point.

Firewall

A firewall is a security appliance, either hardware or software, that filters network traffic based on a preconfigured set of rules.

Power Over Ethernet (PoE)

PoE is a technology that delivers power to devices over data lines, such as an Ethernet cable, thus not requiring a separate power cord.

PoE standards

PoE standards are the IEEE 802.3 standards that define PoE specifications for different device types:

• PoE (802.3af-15.4 W)—WAPs, static surveillance cameras, VoIP phones
• PoE+ (802.3at-30W)—alarm systems, PTZ cameras, video IP phones
• PoE++ (802.3bt [Type 3]-60 W)—multi-radio WAPs, video conferencing equipment
• PoE++ (802.3bt [Type 4]-100 W)—laptops, flat-screen monitors

PoE Delivery Types

There are two types of PoE delivery devices:

• An injector is a midspan device that sits between a non-PoE switch and the AP and supplies power via an Ethernet connection. An injector is used to provide a single device power.

• A switch sits in front of one or more devices and provides power to the Ethernet cable. A PoE switch increases efficiency by providing power to multiple devices rather than requiring an injector for each device while also providing switching capabilities.

Cable Modem

A cable modem is a device that connects to a cable line to provide connectivity. A cable modem is technically no longer a modem, however, since it does not modulate and demodulate analog signals. A cable modem provides faster data transfer speeds than a DSL modem, but is slower than a fiber modem. Similarly, the cost of a cable modem lies between a DSL and fiber modem.

Digital Subscriber Line (DSL) Modem

A DSL modem provides connectivity via a telephone line. A DSL modem offers the slowest transmission speed but is the most cost effective of the modem options. DSL modems are also the most widely available, with access in rural areas that may not offer cable or fiber connections.

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Optical Network Terminal (ONT) Modem

An ONT modem is one that provides connectivity via a fiber-optic line. An ONT modem is the fastest and most reliable of the modems but at a higher cost and less availability than other options.

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Network Interface Card (NIC)

A NIC, also known as a network adapter card, is used to provide the physical interface between a computer and the cabling used for connectivity.

Physical Media Access Control (MAC) Address

A physical MAC address is a unique identifying value that is assigned to a physical NIC by the NIC manufacturer. A MAC address is a 12-digit hexadecimal number arranged in pairs and separated by either a colon or a hyphen. The MAC address is used for communications within a local network to identify specific interfaces in the network.

Note: MAC addresses may also be virtual and logically assigned, such as through a hypervisor.