The CompTIA 220-901 exam is one of two exams requires to obtain the CompTIA A+ (900 series). This exam will cover topics like networking, mobile devices and hardware and network troubleshooting.
1) Of the following choices, which is an industry standard protocol used by computer networks to assign IP Addresses to network nodes and devices?
Dynamic Host Configuration Protocol (DHCP) assigns IP's to network devices. Domain Name Service (DNS) translates between IP Addresses and Domain names. Address Resolution Protocol translates between IP Addresses and MAC Addresses (Reverse-ARP, RARP does the opposite)
This question is filed under objective 2, Networking
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks, whereby a DHCP server dynamically assigns an IP address and other network configuration parameters to each device on the network, so they can communicate with other IP networks A DHCP server enables computers to request IP addresses and networking parameters automatically from the Internet service provider (ISP), reducing the need for a network administrator or a user to manually assign IP addresses to all network devices In the absence of a DHCP server, a computer or other device on the network needs to be manually assigned an IP address, or to assign itself an APIPA address, the latter of which will not enable it to… Read More
2) You are an IT Support Technician for a large office building. A user is complaining their laptop often does not charge or stops charging if they move it. What is most likely the issue?
Laptop's require AC adapters (alternating current) to convert power available in a home or office to DC (direct current). An AC power adapter plugs into the laptop's DC jack. It is called the DC jack because it only accepts DC.
This question is filed under objective 1, Hardware
A DC connector (or DC plug, for one common type of connector) is an electrical connector for supplying direct current (DC) power Compared to domestic AC power plugs and sockets, DC connectors have many more standard types that are not interchangeable The dimensions and arrangement of DC connectors can be chosen to prevent accidental interconnection of incompatible sources and loads Types vary from small coaxial connectors used to power portable electronic devices from AC adapters, to connectors used for automotive accessories and for battery packs in portable equipment … Read More
3) A customer is explaining their PC's symptoms, but you already know what the issue is. Which is the most appropriate action?
You should always do your best not to interrupt a customer while they are speaking, unless it going to take an excessive amount of time.
This question is filed under objective 4, Hardware and Network Troubleshooting
4) Which of the following network topologies provides the most redundancy to protect against network outages?
In a Mesh network topology every network node (router, switch, hub, etc) is connected to every other network node. If a connection breaks, the node can easily communicate with another through multiple existing connections. In reality this is too complex to implement in a large network, but it is still very common to see a hybrid network with several mesh style layers.
This question is filed under objective 2, Networking
A mesh network (or simply meshnet) is a local network topology in which the infrastructure nodes (ie bridges, switches, and other infrastructure devices) connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route data from/to clients This lack of dependency on one node allows for every node to participate in the relay of information Mesh networks dynamically self-organize and self-configure, which can reduce installation overhead The ability to self-configure enables dynamic distribution of workloads, particularly in the event a few nodes should fail This in turn contributes to fault-tolerance and reduced maintenance costs… Read More
5) You are a Server Administrator at a small company. Company policy dictates that all remote connections must be encrypted and accessed using some form of authentication. Which of the following will allow a user to upload a large file from home, while adhering to company policy?
SFTP (SSH File Transfer Protocol) is a protocol for securely uploading files to a remote server. SSH alone is not enough to upload a file and is incorrect. SSH provides the encryption & authentication but does not meet the requirement to upload a file. As SFTP builds upon SSH with functionality for file upload it is the correct answer.
This question is filed under objective 2, Networking
In computing, the SSH File Transfer Protocol (also Secure File Transfer Protocol, or SFTP) is a network protocol that provides file access, file transfer, and file management over any reliable data stream It was designed by the Internet Engineering Task Force (IETF) as an extension of the Secure Shell protocol (SSH) version 20 to provide secure file transfer capabilities The IETF Internet Draft states that, even though this protocol is described in the context of the SSH-2 protocol, it could be used in a number of different applications, such as secure file transfer over Transport Layer Security (TLS) and transfer of management information in VPN applications… Read More
6) Which of the following is a industry standard that provides similar functionality to BIOS?
UEFI (Unified Extensible Firmware Interface) is the next generation of BIOS. Technically it is not a new version or upgrade of BIOS but an entirely new solution. However as it does the same job, it is commonly referred to as a BIOS.
This question is filed under objective 1, Hardware
The Unified Extensible Firmware Interface (UEFI) is a specification that defines a software interface between an operating system and platform firmware UEFI replaces the legacy Basic Input/Output System (BIOS) firmware interface originally present in all IBM PC-compatible personal computers, with most UEFI firmware implementations providing support for legacy BIOS services UEFI can support remote diagnostics and repair of computers, even with no operating system installedIntel developed the original Extensible Firmware Interface (EFI) specifications Some of the EFI's practices and data formats mirror those of Microsoft Windows In 2005, UEFI deprecated EFI 110 (the final release of EFI) The Unified EFI Forum is the industry body that… Read More
7) Which of the following wireless communication standards requires line of sight in order to operate?
Infrared is a wireless technology that requires a clear path between communication devices. A good example of this, is a TV Remote.
This question is filed under objective 2, Networking
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light It is therefore generally invisible to the human eye, although IR at wavelengths up to 1050 nanometers (nm)s from specially pulsed lasers can be seen by humans under certain conditions IR wavelengths extend from the nominal red edge of the visible spectrum at 700 nanometers (frequency 430 THz), to 1 millimeter (300 GHz) Most of the thermal radiation emitted by objects near room temperature is infrared As with all EMR, IR carries radiant energy and behaves both like a wave and like its quantum particle, the photon… Read More
8) Which of the following properly describes the basic operating of a layer 2 network switch?
The wording here is purposefully confusing. While a packet technically refers to layer 3, it is a common misnomer for "data transmitted on a network." It is uncommon to hear someone say a frame was transmitted, simply saying packet is much more common. A switch will receive a frame with a packet inside it and transmit the frame based on the MAC address in the frame header.
This question is filed under objective 2, Networking
A network switch (also called switching hub, bridging hub, and by the IEEE MAC bridge) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer (layer 2) of the OSI model Some switches can also forward data at the network layer (layer 3) by additionally incorporating routing functionality Such switches are commonly known as layer-3 switches or multilayer switchesSwitches for Ethernet are the most common form of network switch… Read More
9) Which of the following will be the first to receive heat leaving a processor?
Thermal paste (or Thermal grease) is designed to conduct heat traveling between two elements. In this case, Thermal paste allows heat to efficiently leave the processor and travel to the heat sink.
This question is filed under objective 1, Hardware
Thermal paste (also called thermal compound, thermal grease, thermal interface material (TIM), thermal gel, heat paste, heat sink compound, heat sink paste or CPU grease) is a thermally conductive (but usually electrically insulating) chemical compound, which is commonly used as an interface between heat sinks and heat sources such as high-power semiconductor devices The main role of thermal paste is to eliminate air gaps or spaces (which act as thermal insulation) from the interface area in order to maximize heat transfer and dissipation Thermal paste is an example of a thermal interface material As opposed to thermal adhesive, thermal paste does not add mechanical strength to the bond between heat source and heat sink… Read More
10) You need to configure a SOHO network to provide IP Addresses to devices on the network. Which feature should be enabled?
Dynamic Host Configuration Protocol (DHCP) is the protocol responsible for assigning IP addresses.
This question is filed under objective 2, Networking
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) networks, whereby a DHCP server dynamically assigns an IP address and other network configuration parameters to each device on the network, so they can communicate with other IP networks A DHCP server enables computers to request IP addresses and networking parameters automatically from the Internet service provider (ISP), reducing the need for a network administrator or a user to manually assign IP addresses to all network devices In the absence of a DHCP server, a computer or other device on the network needs to be manually assigned an IP address, or to assign itself an APIPA address, the latter of which will not enable it to… Read More
11) Why would you use plenum rated cables when installing new cabling in a data-center?
Plenum is a special material used to jacket a cable, this jacket is fire retardant and will reduce the amount of hazardous fumes in the air if the cable is subject to a fire.
This question is filed under objective 2, Networking
Plenum cable is electrical cable that is laid in the plenum spaces of buildings In the United States, plastics used in the construction of plenum cable are regulated under the National Fire Protection Association standard NFPA 90A: Standard for the Installation of Air Conditioning and Ventilating Systems All materials intended for use on wire and cables to be placed in plenum spaces are designed to meet rigorous fire safety test standards in accordance with NFPA 262 and outlined in NFPA 90A Plenum cable is jacketed with a fire-retardant plastic jacket of either a low-smoke polyvinyl chloride (PVC) or a fluorinated ethylene polymer (FEP)… Read More
12) Which of the following network standards can operate at two different channel widths on the same spectrum simultaneously?
Using "channel bonding" the 802.11n wireless standard is capable of operating on two separate channels at the same time. This feature allows 802.11n networks to double their bandwidth, however it can result in increases interference and power usage.
This question is filed under objective 2, Networking
IEEE 80211n-2009, commonly shortened to 80211n, is a wireless-networking standard that uses multiple antennas to increase data rates The Wi-Fi Alliance has also retroactively labelled the technology for the standard as Wi-Fi 4 It standardized support for multiple-input multiple-output, frame aggregation, and security improvements, among other features, and can be used in the 24 GHz or 5 GHz frequency bands As the first Wi-Fi standard that introduced MIMO (Multiple-Input and Multiple-Output) support, sometimes devices/systems that support 80211n standard (or draft version of the standard) are being referred to as MIMO (Wi-Fi products), especially before the introduction of the next generation standard… Read More
13) You are a Desktop Technician in a company's IT Department. You need to find the hardware specifications of a desktop, however the device does not have an operating system installed. Which of the following options will display this information?
The BIOS (Basic Input Output System) firmware application will display information like the CPU, RAM and hard drive information. It is not necessary to have an operating system installed to utilize the BIOS.
This question is filed under objective 1, Hardware
BIOS (, BY-oss, -ohss an acronym for Basic Input/Output System and also known as the System BIOS, ROM BIOS or PC BIOS) is firmware used to perform hardware initialization during the booting process (power-on startup), and to provide runtime services for operating systems and programs The BIOS firmware comes pre-installed on a personal computer's system board, and it is the first software to run when powered on The name originates from the Basic Input/Output System used in the CP/M operating system in 1975 The BIOS originally proprietary to the IBM PC has been reverse engineered by some companies (such as Phoenix Technologies) looking to create compatible systems… Read More
14) A supervisor has asked you to update the BIOS on a customer's laptop. Where is the best place to find the correct BIOS firmware?
The best place to find any firmware or software upgrade for a device is through manufacture support. Although it may be possible to find the correct software elsewhere, the manufacture is likely to have tested each version prior to release.
This question is filed under objective 1, Hardware
BIOS (, BY-oss, -ohss an acronym for Basic Input/Output System and also known as the System BIOS, ROM BIOS or PC BIOS) is firmware used to perform hardware initialization during the booting process (power-on startup), and to provide runtime services for operating systems and programs The BIOS firmware comes pre-installed on a personal computer's system board, and it is the first software to run when powered on The name originates from the Basic Input/Output System used in the CP/M operating system in 1975 The BIOS originally proprietary to the IBM PC has been reverse engineered by some companies (such as Phoenix Technologies) looking to create compatible systems… Read More
15) What CAT version is RATED to provide a transmission speed of 1000 Mbps?
CAT5e is rated at 1000 megabits per second. CAT 6a is rated for 10 gigabits per second.
This question is filed under objective 2, Networking
Category 5 cable (Cat 5) is a twisted pair cable for computer networks Since 2001, the variant commonly in use is the Category 5e specification (Cat 5e) The cable standard provides performance of up to 100 MHz and is suitable for most varieties of Ethernet over twisted pair up to 1000BASE-T (Gigabit Ethernet) Cat 5 is also used to carry other signals such as telephony and video This cable is commonly connected using punch-down blocks and modular connectors Most Category 5 cables are unshielded, relying on the balanced line twisted pair design and differential signaling for noise rejection … Read More
16) You are trying to use RDP to control a Windows computer from your office to an accountant's computer in the corporate office building. What port should be opened in the firewalls between the two locations?
Remote Desktop Protocol (RDP) uses port 3389 to communicate.
This question is filed under objective 2, Networking
Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft which provides a user with a graphical interface to connect to another computer over a network connection The user employs RDP client software for this purpose, while the other computer must run RDP server software Clients exist for most versions of Microsoft Windows (including Windows Mobile), Linux, Unix, macOS, iOS, Android, and other operating systems RDP servers are built into Windows operating systems an RDP server for Unix and OS X also exists By default, the server listens on TCP port 3389 and UDP port 3389Microsoft currently refers to their official RDP client software as Remote Desktop Connection, formerly "Terminal Services Client"… Read More
17) Which of the following is the default TCP/IP port for the standard HTTP protocol?
The Hyper Text Transfer Protocol (HTTP) uses port TCP 80 by default. The encrypted version (HTTPS) uses TCP 443.
This question is filed under objective 2, Networking
The Hypertext Transfer Protocol (HTTP) is an application layer protocol for distributed, collaborative, hypermedia information systems HTTP is the foundation of data communication for the World Wide Web, where hypertext documents include hyperlinks to other resources that the user can easily access, for example by a mouse click or by tapping the screen in a web browser Development of HTTP was initiated by Tim Berners-Lee at CERN in 1989 Development of early HTTP Requests for Comments (RFCs) was a coordinated effort by the Internet Engineering Task Force (IETF) and the World Wide Web Consortium (W3C), with work later moving to the IETF… Read More
18) Select the option that could properly be used to describe the characteristics of a VGA cable?
Video Graphics Array (VGA) cables use analog signals and a 15 pin connector.
This question is filed under objective 1, Hardware
Video Graphics Array (VGA) is a video display controller and accompanying de-facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years The term can now refer either to the computer display standard, the 15-pin D-subminiature VGA connector, or the 640×480 resolution characteristic of the VGA hardware VGA was the last IBM graphics standard to which the majority of PC clone manufacturers conformed, making it the lowest common denominator that virtually all post-1990 PC graphics hardware can be expected to implementIBM intended to supersede VGA with the Extended Graphics Array (XGA) standard, but failed… Read More
19) Which of the following properly describes the purpose of a KVM?
A KVM (Keyboard Video Mouse) Switch is used to use a single set of peripherals with multiple physical machines.
This question is filed under objective 1, Hardware
A KVM switch (with KVM being an abbreviation for "keyboard, video and mouse") is a hardware device that allows a user to control multiple computers from one or more sets of keyboards, video monitors, and mice … Read More
20) ECC type memory would be most commonly found in which type of device?
ECC memory is most commonly found in servers because a server has a much higher load and fault tolerance requirement than an average computer or device.
This question is filed under objective 1, Hardware
Error-correcting code memory (ECC memory) is a type of computer data storage that can detect and correct the most-common kinds of internal data corruption ECC memory is used in most computers where data corruption cannot be tolerated under any circumstances, such as for scientific or financial computing Typically, ECC memory maintains a memory system immune to single-bit errors: the data that is read from each word is always the same as the data that had been written to it, even if one of the bits actually stored has been flipped to the wrong state Most non-ECC memory cannot detect errors, although some non-ECC memory with parity support allows detection but not correction… Read More
21) Which of the following options would typically be associated with encryption?
TPM (Trusted Platform Module) is a standard cryptoprocessor used to store cryptographic keys
This question is filed under objective 1, Hardware
Trusted Platform Module (TPM, also known as ISO/IEC 11889) is an international standard for a secure cryptoprocessor, a dedicated microcontroller designed to secure hardware through integrated cryptographic keys … Read More
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