A+ Certification Practice Exam Questions (ExamCompass Core 1 Practice Exams 4-6)

What is DHCP?

Dynamic Host Configuration Protocol • Automatically assigns IP settings • Uses UDP 67/68 • Memory: Server 67, client 68

Which DHCP port belongs to the client?

UDP 68 • Memory: Client receives on 68

Which DHCP port belongs to the server?

UDP 67 • Memory: Server listens on 67

A PC shows 169.254.x.x and cannot reach the Internet. Best thing to check?

DHCP availability • 169.254.x.x = APIPA • Memory: 169.254 = DHCP problem

What is APIPA?

Automatic Private IP Addressing • Self-assigned when DHCP is unavailable • IPv4 link-local • Memory: 169.254.x.x

A PC can ping an IP address but not a hostname. Best suspect?

DNS • Memory: IP works + name fails = DNS

What does DNS do?

Translates hostnames/FQDNs to IP addresses • Port 53 • Memory: DNS = names

What are the private IPv4 ranges?

10.0.0.0/8 • 172.16.0.0–172.31.255.255 • 192.168.0.0/16 • Memory: 10 / 172.16–31 / 192.168

An address is 172.20.5.10. What type is it?

Private IPv4 address • Memory: 172.16–31 is private

What is the common IPv4 loopback address?

127.0.0.1 • Tests the local TCP/IP stack • Memory: 127 = yourself

What is a default gateway?

Router used to reach networks outside the local subnet • Memory: Gateway = way out

What port does SSH use?

TCP 22 • Secure remote terminal • Memory: SSH = 22

What port does Telnet use?

TCP 23 • Unencrypted remote terminal • Memory: One after SSH

What port does SMTP use?

TCP 25 • Sends email • Memory: S = Send

What port does HTTP use?

TCP 80 • Unencrypted web • Memory: Web = 80

What port does HTTPS use?

TCP 443 • Encrypted web • Memory: Secure web = 443

What port does SMB use?

TCP 445 • Windows file/printer sharing • Memory: SMB = shares

What port does RDP use?

TCP/UDP 3389 • Remote Desktop Protocol • Memory: RDP = 3389

What port does LDAP use?

TCP/UDP 389 • Directory services • Memory: LDAP = directory

What ports does FTP commonly use?

20/21 • File Transfer Protocol • Memory: FTP uses two

What port does POP3 use?

TCP 110 • Email retrieval/download • Memory: POP pulls

What port does IMAP use?

TCP 143 • Email retrieval + synchronization • Memory: IMAP syncs

No Ethernet link lights appear after connecting a cable. Best interpretation?

No physical Ethernet signal/link • Check cable, NIC, or switch port first • Memory: Dark link light = Layer 1

What is a cable tester used for?

Checks continuity and wiring • Finds opens/crossed wires • Memory: Tester = cable health

What is a tone generator + probe used for?

Trace and identify a cable run • Memory: Tone = where does it go?

What is a loopback plug used for?

Tests a physical network/serial interface • Loops transmitted data back to the port • Memory: Loopback = test port

What is a crimper used for?

Attaches a connector to a cable • Memory: Crimper = connector installer

Cables were replaced but a WAN interface still shows errors. Best tool?

Loopback plug • Tests whether the interface itself is faulty • Memory: Cable good → test port

What is an F-connector used for?

Threaded coax connector • Cable TV / cable modem • Memory: F = coax

What is RJ45 used for?

Ethernet twisted-pair networking • Memory: RJ45 = network

What does AAA stand for?

Authentication • Authorization • Accounting • Memory: Who are you? What can you do? What did you do?

What is authentication?

Verifies identity • Memory: Who are you?

What is authorization?

Determines what an authenticated user is allowed to access/do • Memory: What can you do?

What is accounting?

Tracks/logs user activity and resource use • Memory: What did you do?

A login system checks a fingerprint before granting access. Which AAA function?

Authentication • Memory: Identity check

A user is logged in but cannot open a restricted folder. Which AAA function controls this?

Authorization • Memory: Permissions after login

An admin reviews logs showing who connected and for how long. Which AAA function?

Accounting • Memory: Activity records

What are biometrics?

Authentication using a physical trait • Examples: fingerprint, face • Memory: Something you are

What is NFC?

Near-Field Communication • Very short-range wireless • Used for tap-to-pay/proximity actions • Memory: Near = very near

A workstation should unlock when an authorized badge is held a few centimeters away. Best technology?

NFC • Memory: Very short-range proximity

What is Bluetooth?

Short-range PAN technology • Used for headsets, watches, keyboards, mice • Memory: Bluetooth = peripherals

A smartwatch is not visible to a phone for syncing. First thing to check?

Bluetooth enabled/pairing mode • Memory: Watch ↔ phone = Bluetooth

What is MDM?

Mobile Device Management • Centralized policies for apps, data, camera, and device settings • Memory: Company controls phone

A corporate phone refuses to install an unapproved app. Most likely cause?

MDM policy • Memory: Blocked app = management policy

What is a mobile hotspot?

Phone shares cellular Internet • Other devices commonly connect over Wi-Fi • Memory: Phone becomes router

A remote site has no wired or Wi-Fi Internet. Best quick connection using a phone?

Mobile hotspot • Memory: Phone supplies Internet

What is ECC RAM?

Error Correcting Code memory • Detects/corrects certain memory errors • Requires motherboard support • Memory: ECC = error correction

A server worked with non-ECC RAM but will not boot after installing ECC RAM. Best explanation?

Memory type is incompatible with the motherboard • Memory: RAM must match board support

What does multi-channel memory provide?

Higher memory bandwidth by using multiple channels/modules • Memory: More channels = more throughput

What is BIOS/UEFI?

Firmware that initializes/configures hardware • Controls boot settings before OS loads • Memory: Before the OS

A PC tries to boot from a USB drive instead of the internal SSD. Best fix?

Change boot order in BIOS/UEFI • Put internal drive before removable media • Memory: Boot order lives in firmware

What does the motherboard/CMOS battery maintain?

System clock and firmware settings while main power is removed • Memory: Clock forgets = battery

Date/time resets whenever the PC is unplugged. Most likely cause?

Failing motherboard/CMOS battery • Memory: Clock reset = battery

What is M.2?

Small internal form factor/interface • Common for SSDs and some network cards • Memory: M.2 = small internal

What is NVMe?

Non-Volatile Memory Express • High-speed storage protocol commonly using PCIe • Memory: NVMe = fast PCIe storage

What is a VLAN?

Virtual Local Area Network • Logical grouping/segmentation of devices • Can share physical switches while remaining separate broadcast domains • Memory: VLAN = logical LAN

Several departments share one physical switch but need separate broadcast domains. Best solution?

VLANs • Memory: One switch, separate networks

What is a VPN?

Virtual Private Network • Encrypted tunnel across an untrusted network • Memory: VPN = secure tunnel

How are VLAN and VPN different?

VLAN = network segmentation • VPN = encrypted tunnel • Memory: Divide vs tunnel

What does a router do?

Connects different IP networks • Uses IP addresses to forward packets • Layer 3 • Memory: Router = between networks

What does a switch do?

Connects devices within a LAN • Uses MAC addresses to forward frames • Layer 2 • Memory: Switch = inside LAN

What is IaaS?

Infrastructure as a Service • Provider supplies compute/storage/networking • Customer manages OS + apps • Memory: I = infrastructure

Cloud provider gives CPU, RAM, storage, and networking; you install the OS and applications. Model?

IaaS • Memory: Hardware-like resources

What is PaaS?

Platform as a Service • Provider supplies an application development/deployment platform • Memory: P = platform

What is SaaS?

Software as a Service • Finished app provided to user • Provider manages most of the stack • Memory: S = software ready

Users open a browser and use email with no local application management. Model?

SaaS • Memory: Just use the app

What is cloud elasticity?

Resources scale up or down as demand changes • Memory: Elastic = stretch/shrink

A service adds instances during busy hours and removes them at night. Characteristic?

Elasticity • Memory: Demand changes → scale

What is high availability?

Service stays accessible despite component/site failures • Uses redundancy • Memory: Failure without outage

An app runs in multiple data centers so one site can fail without downtime. Characteristic?

Availability • Memory: Redundancy keeps service up

What is metered utilization?

Cloud usage is measured • Can be used for usage-based billing • Memory: Meter = measure

Cloud bill is based on CPU time, storage, and bandwidth consumed. Characteristic?

Metered utilization • Memory: Pay for measured use

What is file synchronization in cloud systems?

Keeps data consistent across multiple locations/instances • Memory: Same files everywhere

What is direct-burial Ethernet cable?

Designed for underground/outdoor installation • Often includes waterproof gel and grounding • Memory: Buried = weather protection

What is plenum-rated cable?

Low-smoke/fire-resistant jacket • Used in plenum air spaces • Memory: Plenum = air space

What do T568A and T568B define?

RJ45 Ethernet pinout/wire color order • Assignments for 8 conductors • Memory: A/B = wire order

What is VGA?

15-pin analog video connection • Memory: VGA = analog

What is DisplayPort?

Digital display connection • Memory: DP = digital display

What is eSATA?

External SATA connection for storage • Memory: e = external

What is Molex commonly used for?

Powering internal devices such as older drives, optical drives, and fans • Memory: Molex = internal power

What is an LC connector?

Small fiber-optic connector • Common on switches/routers/servers • Memory: LC = fiber

A projector keeps flickering after resolution/refresh settings are corrected. Best next step?

Replace/test the video cable • Memory: Settings good → suspect cable

What is native resolution?

Display's designed pixel resolution • Usually gives the sharpest image • Memory: Native = sharpest

LCD image is fuzzy and not crisp. Most likely setting?

Non-native resolution • Memory: Fuzzy = resolution

What is the print spooler?

Service/software that stores, queues, and sends print jobs • Memory: Queue = spooler

Many jobs are stuck in the print queue and nothing prints. Best next step?

Restart the print spooler • Memory: Stuck queue = spooler

What does a printer driver do?

Formats print jobs for a specific printer • Exposes printer features/options • Memory: Driver translates for printer

Only one user's output is garbled while other users print normally. Best suspect?

Incorrect/mismatched printer driver or page description language • Memory: One user + garbled = driver

Printer tray options are missing from the user's print dialog. Best fix?

Update/correct the printer driver • Memory: Missing features = driver

What is a thermal printer?

Uses heat-sensitive paper • Common for receipts and labels • Memory: Thermal = heat paper

A printer uses a special roll that darkens with heat. Printer type?

Thermal printer • Memory: Heat-sensitive roll

Laser output gradually becomes lighter across pages. Likely cause?

Low toner • Memory: Fading = toner

Laser output has repeating dots/speckles. Likely cause?

Dirty/damaged optical drum or cleaning process • Memory: Repeating marks = drum

A PC powers off during heavy graphics/CPU load but works during light use. Likely cause?

Overheating / cooling problem • Check fans and airflow • Memory: Heavy load + shutdown = heat

A system becomes slow, but CPU, RAM, and network usage look normal. Best next check?

Run storage/drive diagnostics • Memory: Rule out the drive

The PC says 'Operating system not found' and internal drive cables are connected. Best simple next check?

Remove/check removable boot devices • Then verify firmware boot order • Memory: Don't replace drive first