Cheat sheet
CompTIA A+ Cheat Sheet
Core 1 Hardware
- 13-28% of exam
- Mobile Devices Hardware Storage RAM vs Storage
Core 1 Networking
- 11-23% of exam
- Ports Networking Cloud NAT vs DHCP
Core 2 Systems
- 23-28% of exam
- Windows Tools Linux + macOS UEFI vs BIOS Boot Triage
Security + Ops
- 21-28% of exam
- Security Procedures Malware Triage Troubleshooting Steps
Quick Facts
- Exams 220-1201 + 1202
- Questions Max 90 each
- Time 90 min each
- Pass C1 675/900
- Pass C2 700/900
- Format MCQ + PBQ
- Skill Troubleshoot first
Laser Process HA
- Process -> Charge -> Expose -> Develop
- Transfer next Fuse toner Clean drum Laser only
RAM vs Storage HA
RAM
- Volatile
- Active work
- Fast
Storage
- Persistent
- Saved data
- Slower
- Work vs save
Mobile Devices HA
- Touchpad Pointer input
- Digitizer Touch layer
- Dock Port expansion
- NFC Near-field pairing
- Bluetooth Short-range wireless
- Hotspot Shared cellular
HDD vs SSD HA
HDD
- Mechanical
- Cheaper
- Moving parts
SSD
- Flash
- Faster
- No moving
- Spinning vs flash
Hardware HA
- CPU Executes instructions
- RAM Volatile memory
- Motherboard Component backbone
- PSU Power supply
- GPU Graphics processing
- TPM Hardware trust
Storage HA
- HDD Spinning disk
- SSD Flash storage
- NVMe PCIe storage
- SATA Drive interface
- RAID 0 Stripe speed
- RAID 1 Mirror redundancy
Printers HA
- Laser Toner process
- Inkjet Liquid ink
- Thermal Heat paper
- Impact Ribbon strike
- Fuser Bonds toner
- Duplex Two-sided print
Mail Ports NE
- SMTP 25 | POP3 110 | IMAP 143
- SMTP sends POP downloads IMAP syncs HTTPS 443
NAT vs DHCP NE
NAT
- Translates addresses
- Internet sharing
- Router
DHCP
- Leases addresses
- Client config
- Scope
- Translate vs assign
Network Triage NE
- 169.254 IP → Check DHCP
- No name → Check DNS
- No gateway → Check router
- Weak Wi-Fi → Check channel
- No link → Check cable
- VPN fails → Check creds
Ports NE
- 20/21 FTP
- 22 SSH
- 25 SMTP
- 53 DNS
- 80 HTTP
- 110 POP3
- 143 IMAP
- 443 HTTPS
IMAP vs POP3 NE
IMAP
- Server sync
- Port 143
- Multi-device
POP3
- Download mail
- Port 110
- Single-client
- Sync vs download
Networking NE
- DHCP Leases IP
- DNS Names to IP
- NAT Address translation
- APIPA 169.254 fallback
- SSID Wireless name
- VPN Encrypted tunnel
Cloud NE
- IaaS Virtual infrastructure
- PaaS Managed platform
- SaaS Hosted app
- VDI Virtual desktop
- Hypervisor Runs VMs
- Snapshot Point copy
UEFI vs BIOS SY
UEFI
- Modern firmware
- Secure Boot
- GPT
BIOS
- Legacy firmware
- MBR
- Older systems
- Modern vs legacy
Boot Triage SY
- No power → Check PSU
- POST beeps → Check hardware
- No OS → Check boot order
- Slow boot → Check startup
- Driver issue → Device Manager
- Disk issue → Disk Mgmt
Windows Tools SY
- Device Mgr Driver status
- Disk Mgmt Partitions
- Event Viewer System logs
- Task Manager Processes
- Services Daemon control
- gpedit Local policy
Troubleshooting Steps SE
- Identify -> Theory -> Test -> Plan
- Implement fix Verify function Document outcome Escalate if needed
Malware Triage SE
- Malware confirmed → Quarantine host
- Need evidence → Preserve logs
- Remove threat → Scan offline
- Fix gaps → Patch system
- Restore data → Clean backup
- Prevent repeat → User training
Security SE
- MFA Extra factor
- BitLocker Disk encryption
- Firewall Traffic filter
- EDR Endpoint detection
- Phishing Fake lure
- Quarantine Isolate file
Procedures SE
- Change Controlled update
- Ticket Work record
- Backup Recovery copy
- ESD strap Static protection
- SDS Safety sheet
- Chain custody Evidence tracking
Common Traps
DHCP mixup
- DHCP assigns IP ≠ DNS resolves names
Memory mixup
- RAM is volatile ≠ Storage persists
Firmware mixup
- UEFI is modern ≠ BIOS is legacy
Mail mixup
- SMTP sends mail ≠ IMAP syncs mail
Malware order
- Verify, then quarantine ≠ Restore point after cleanup
Last Minute
- 1. Core 1 = devices/network/hardware
- 2. Core 2 = OS/security/ops
- 3. DHCP gives IP
- 4. DNS gives names
- 5. NAT translates addresses
- 6. RAM loses power
- 7. SSD has no moving parts
- 8. UEFI supports Secure Boot
- 9. SMTP sends email
- 10. IMAP syncs email