220-801 Cram Sheet
- Motherboards – Connect everything together. Typical form factors include ATX (most common), microATX, ITX, and BTX. AMD and older intel chipsets include a northbridge that connects the CPU, RAM, and x16 PCIe devices, and southbridge that connects secondary systems such as USB, SATA, IDE, and sound. Types of expansion buses include PCI, AGP, PCI Express (PCIe), AMR, CNR, and PC Card (PCMCIA). Newer Intel chipset designs incorporate northbridge functionality into the CPU that connects to a single-chip chipset via DMI or QPI. AMD CPU to chipset connection is HyperTransport.
BIOS (Basic Input/Output System) identifies, tests, and initializes components and boots to hard drive. CMOS (complementary metal-oxide semiconductor) stores time/date, passwords. CR2032 lithium battery provides power to CMOS.
In BIOS, you can configure: time/date, boot device priority (boot order), passwords, power management, WOL (Wake On LAN), monitoring.
To update BIOS, flash it with new firmware.
- The Central Processing Unit (CPU) or processor takes care of all calculations.
Intel CPUs (Core i3/i5/i7) use LGA (Land Grid Array) 1155 sockets. Older Intel CPUs (Core 2) use LGA 775 sockets. AMD Phenom II CPUs use AM2+ and AM3 sockets. AMD FX CPU uses AM3+ socket.
L1/L2 cache in each core. L3 cache is shared among entire CPU.
Thermal compound is required whenever heat sink is installed.
- Random Access Memory (RAM) types include SDRAM, DDR, DDR2, DDR3, RDRAM and SODIMMs.
Example of DDR3-800 data transfer calculation: 800 MT/s x 8= 6,400 MB/s. Dual channel is double width, 128-bit bus. Latency measured as CL or CAS.
- ATX 12V 2.x Power Supplies connect to the motherboard by way of 24-pin cable + 4-pin for CPU and 6 or 8-pin for video.
- Hard Disk Drives are nonvolatile (meaning they don’t lose data when power off) devices that store data, generally 3.5”. Types of HDD include:
SATA: Serial ATA drives come in 150, 300, and 600 MB/s versions (1.5/3.0/6.0 Gb/s), use a 15-pin power connector and a 7-pin data connector.
PATA: Parallel ATA drives range between 33 MHz and 133 MHz (Ultra ATA/33 through /133), use a 4-pin Molex power connector, 40-pin IDE ribbon cable for data, and can be jumpered as a single, master, slave or cable select.
SCSI: Small Computer System Interface drives range in transfer rates from 160 MB/s to 640 MB/s and use 68-pin, 80-pin or serial connectors.
- RAID stands for Redundant Array of Inexpensive Disks. RAID 0 is striping, RAID 1 is mirroring and RAID 5 is striping with parity. RAID 10 is mirrored sets in a striped set. RAID 0 is not fault-tolerant. If RAID 1 uses two disk controllers, it is disk duplexing.
- Optical disc drives use removable media to store and retrieve data, typically 5.25”.
Types of optical discs include:
CD-ROM: Data CDs can typically hold 700 MB, can read and write at up to 52x (7.8 MB/s) and rewrite at up to 32x (4.8 MB/s).
DVD-ROM: DVDs have a capacity ranging from 4.7 GB (DVD-5) to 17 GB (DVD-18 dual-sided and dual-layered).
Recording technologies include DVD+R, DVD-R, DVD+RW and DVD-RW.
Blu-ray: Blu-rays are used for HD and games and have a capcity of 50 GB and a write speed between 1x and 12x (36 Mbps – 432 Mbs). Blu-ray drives connect via SATA only.
- Floppy drives use 1.44 MB 3.5” disks and connect to the motherboard via 34-pin data cable and 4-pin mini (Berg) power connector.
- Solid-state media includes solid-state hard drives (SSD), USB flash drives, CompactFlash and Secure Digital (SD) cards.
- Laptops are smaller versions of desktop PCs. They have replaceable items such as keyboards, SODIMM RAM, displays, inverters, optical discs and 2.5” hard drives. Laptops use PC Card (PCMCIA), CardBus and ExpressCard technologies. They have a “Fn” key for implementing secondary key functions.
- Video cards connect to motherboards by way of x16 PCIe (most common, typically black), AGP (brown), or PCI (white) expansion slots. Video connector types include DVI, VGA, HDMI, DisplayPort, S-Video and component Video/RGB. Common color depths include 16-bit, 24-bit and 32-bit. Common resolutions include XGA (1024×76, WXGA (1280×720), SXGA+ (1280×1024), UXGA (1600×1200), WSXGA+ (1680×1050) and WUXGA (1920×1200).
- Sound cards connect as x1 PCIe or PCI cards and normally have PC 99 color-coded 1/8” mini-jacks for I/O and speakers, and optical I/Os known as S/PDIF (example: TOSLINK).
- USB (Universal Serial Bus) can have up to 127 devices. USB 1.1 (full speed) runs at 12 Mbps with a max cable length of 3 meters. USB 2.0 (high-speed) runs at 480 Mbps with a max cable length of 5 meters. USB 3.0 (Superspeed) runs at 5 Gbps. Computers usually have Type A USB connectors built in.
- IEEE 1394a (FireWire 400) runs at 400 Mbps. IEEE 1394b (FireWire 800) runs at 800 Mbps. IEEE 1394b also specifies 1600 Mbps and 3200 Mbps. IEEE 1394 chains can have up to 63 devices.
- Printers include laser, inkjet, thermal and impact (dot-matrix). The six main steps in the laser printing process are Cleaning, Conditioning (charging), Writing (exposing), Developing, Transferring and Fusing. Processing is considered another step before printing begins.
- Custom PCs include:
Audio/Video workstations – needs special A/V cards, fast hard drives and multiple monitors
CAD/CAM workstations – needs powerful CPUs, video cards and lots of RAM
Thin Clients – Low resources, relies on server, diskless, embedded operating system
Home Server PC – Has a fast NIC, RAID arrays, HomeGroup
HTPC (Home Theater PC) – usually small form factor, surround sound, HDMI output & TV Tuner
Gaming PC – needs powerful CPU and video card
Virtualization workstation – needs powerful CPU and lots of RAM.
– Type 1 hypervisor is native or bare metal
– Type 2 is hosted, runs on top of operating system.
- LAN = Local Area Network
WAN = Wide Area Network
MAN = Metropolitan (or Municipal) Area Network
PAN = Personal Area Network
- Switches connect computers together in a LAN.
Routers connect two or more LANs and connect LANs to the Internet.
Firewalls protect individual computers and networks from unwanted intrusion.
- Network topologies include Star (most common), Ring, Bus, Mesh and other hybrids (like Star-Bus and Hierarchical Star).
- IPv4 addresses are 32 bit dotted-decimal numbers (like 192.168.1.1) and can be statically (manually) inputed or dynamically (automatically) assigned by DHCP.
IP Classes include:
Class A Range: 1-126, Subnet Mask: 255.0.0.0, Private 10.x.x.x
Class B Range: 128-191, Subnet Mask: 255.255.0.0, Private 172.16.0.0 – 172.31.255.255
Class C Range: 192-223, Subnet Mask: 255.255.255.0, Private 192.168.x.x
- IPv6 addresses are 128-bit hexadecimal numbers (like 2001:7120:0000:8001:0000:0000:0000:1F10). The loopback address is ::1.
Unicast IPv6 addresses are assigned to a single interface and are the most common type.
- Common network speeds are 1000 Mbps (Gigabit Ethernet) and 100 Mbps (Fast Ethernet).
- Networking Protocols include:
FTP – File Transfer Protocol : Port 21
SSH – Secure Shell : Port 22
Telnet : Port 23
SMTP – Simple Mail Transfer Protocol : Port 25
DNS – Domain Naming System (or Service) : Port 53
HTTP – Hypertext Transfer Protocol : Port 80
POP3 – Post Office Protocol : Port 110
IMAP – Internet Message Access Protocol : Port 143
HTTPS – HTTP Secure : Port 443
RDP – Remote Desktop Protocol : Port 3389
- Cabling Standards include:
Category 3: 10Mbps
Category 5: 100Mbps
Category 5e: Rated for 100Mbps and gigabit networks
Category 6: Rated for 100 Mbps and gigabit networks
- Wireless Ethernet Versions: (Name – Data Transfer Rate – Frequency)
802.11a – 54 Mbps – 5GHz
802.11b – 11 Mbps – 2.4 GHz
802.11c – 54 Mbps – 2.4 GHz
802.11n – 600 Mbps – 5 and 2.4 GHz
- Bluetooth is a short-range technology aimed at simplifying communications and synchronization among network devices. Bluetooth is divided into three classes:
Class I has a maximum transmission range of 100 meters. Max data transfer rate of 721 Kbps.
Class II (most common) has a maximum range of 10 meters. Max data transfer rate of 2.1 Mbps.
Class III is a short range and hardly used at a maximum range of 1 meter.
- Port forwarding forwards an external network port to an internal IP address and port.
- Port triggering enables you to specify outgoing ports that your computer uses for special applications. Their corresponding inbound ports open automatically when the sessions are enabled.
Do not open power supplies
Test AC outlets before use
Use CO2-based BC fire extinguisher on electrical fires and call 911
Employ Cable Management whenever possible
MSDS =Material Saftey DataSheets. Consult when encountering a product with chemicals (toner cartridges and cleaners).
- ESD = Electro-Static Discharge. Prevent with antistatic strap and mat, touching computer chassis, use of antistatic bags, unplugging computers before working on them and increasing humidity.
- Incident Response: First response – Identify what happened – Document – Set up Chain of Custody (chronological paper trail).
Be punctual to clients
Listen to customer
Set and meet expectations
Avoid distractions (phone, etc)
Avoid confidential data
220-802 Cram Sheet
- CompTIA 6-Step Troubleshooting Process:
1. Identify the problem.
2. Establish a theory of probably cause. (Question the obvious)
3. Test the theory to determine cause.
4. Establish a plan of action to resolve the problem and implement the solution.
5. Verify full system functionality and if applicable implement preventative measures.
6. Document findings, actions, and outcomes.
- Power is good, but no display?
– Check the big four: video, CPU, RAM, and motherboard.
- Time/Date reset to Jan 1st, 2000?
– Check lithium battery on motherboard.
- Trouble with CPU?
– Check if CPU is secure, CPU fan, heat sink and thermal compound, and overclocking setting in BIOS.
- Noisy computer?
– Check CPU fan, case fan, power supply fan, and use compressed air and vacuum.
- RAM issue?
– Reseat modulesl; clean with compressed air.
– Try RAM heat sinks.
BIOS beep codes or displayed errors?
– Consult motherboard documentation and use POST card tester.
- Power issues?
– Test AC outlet with receptacle tester or multimeter. Test power supply with PSU tester or multimeter. Do not open a (PSU) power supply; a PSU qualifies as a field replaceable unit (FRU).
- Slow hard drive?
– Defrag it, use disk cleanup, and scan drive with antivirus software.
Drive isn’t recognized?
– Check connections, check in BIOS, initialize, partition, and format in Disk Management.
– If not SCSI, replace it!
Floppy LED stays on?
– Check for upside-down data cable.
- No second screen on laptop?
– Check Fn key.
Laptop display blank?
– Check resolution settings, inverter, backlight, or damage to LCD.
- Printer paper jam?
– Power cycle, check paper tray, rollers, paper type, fuser, and entire paper path.
– Check toner cartridge and transfer corona wire.
Lines or smearing?
– Check drum, primary corona wire, and replace toner cartridge.
Toner not staying on paper?
– Check fusing assembly.
– Check driver.
– Check drum and toner cartridge,
– Check power, network connection, if printer is shared, proper IP address, and see if default printer.
- Test network connections with patch tester, LAN cable tester, tone and probe. Test NIC with loopback plug.
- Windows 7 minimum requirements:
CPU = 1 GHz
RAM = 1 GB (2 GB for 64-bit)
Free disk space = 16 GB (20 GB for 64-bit)
- Windows Vista minimum requirements:
CPU = 800 MHz
RAM = 512 MB
Free disk space = 15 GB
- Windows XP minimum requirements:
CPU = 233 MHz
RAM = 64 MB
Free disk space = 1.5 GBMedia Center requirements:
CPU = 1.6 GHz
RAM = 256 MB
- Setuperr.log contains setup errors during an installation of Windows.
- Graphical User Interface (GUI) includes the desktop, icons, taskbar, Start menu, Quick Launch, Notification area, application windows and dialog boxes, and gadgets.
- Command Prompt is the command-line utility in Windows. To run in elevated mode: Click Start > All Programs > Accessories; then right-click Command Prompt and select Run as Administrator.
- Snap-ins are console windows that can be added to a Microsoft Management Console (MMC). Example: Computer Management and Performance Monitor.
- Libraries in Windows 8 logically represent user-defined collections of folders.
- Common system tools include Device Manager, System Information tool, Task Manager, and Msconfig.
- User data can be migrated using Windows Easy Transfer (Windows 7 and Vista only), User Migration Tool (USMT), and Files and Settings Transfer Wizard (XP).
- The Registry is a database that stores the settings for Windows. It can be accessed by opening the Run prompt and typing regedit.exe. Hives store settings; a commonly modified hive is HKEY_LOCAL_MACHINE.
- Remote Desktop software enables a user to see and control the GUI of a remote computer.
- The %windir% (or %systemroot%) in Windows 7/Vista/XP is C:\Windows by default.
- Windows 7/Vista boot files include Bootmgr, Winload.exe. BCD. Windows XP boot files include NTLDR, Boot.ini, and NTdetect.com.In Windows 7/Vista: Bootrec/fixboot repairs Bootmgr, Bootrec/fixmbr rewrites the master boot record, and Bootrec/rebuildbcd rebuilds the boot configuration data store.
In Windows XP: fixmbr repairs the MBR; fixboot writes new boot sector information.
- Directories can be added with the MD command, removed with the RD command, and navigated to with the CD command.
- File checking command-line tools that can be used in Windows include Chkdsk (/F fixes errors, /R locates bad sectors and recovers info) and SFC (System File Checker); SFC /scannow is common.
- A hard disk can have four partitions: up to four primary partitions; but only one extended partition.
Logical drives are sections of an extended partition.
The Active partition is the one that is booted from; it usually contains the OS.
Any section of a hard drive with a letter is called a volume.
- A service pack (SP) is a group of updates, bug fixes, updated drivers, and security fixes installed from one downloadable package or from one disc.
- Windows Update can be accessed from Start > All Programs > Windows Update.
- Backups can be accomplished in Windows 7 with Backup and Restore, in Vista with Backup Status and Configuration, and in XP with NTBackup.
- System Restore can fix issues caused by defective hardware or software by reverting back to an earlier time.
- F8 brings up the Advanced Boot Options Menu (ABOM) that includes options such as Safe Mode, Enable low-resolution video, and Last Known Good Configuration.
Safe Mode boots the system with minimal drivers.
- The Windows 7/Vista Windows Recovery Environment (WinRE) includes System Recovery Options such as Startup Repair, System Restore, and Command Prompt.
- Windows XP uses the Recovery Console as its repair environment.
- The Event Viewer warns about possible issues and displays errors as they occur within three main log files: System, Application, and Security.
Security displays auditing information.
- A stop error (also known as a Blue Screen of Death or BSOD) completely halts the operating system and displays a blue screen with various text and code. Can be caused by faulty hardware or bad drivers.
- Processes can be stopped in the Task Manager or with the taskkill command in the Command Prompt.
- Common networking command-line tools include the following:
– IPConfig: Displays current TCP/IP network configuration values; IPConfig/all shows additional information (like MAC address).
– Ping: Tests whether another host is available over the network (example: ping 192.168.1.1). Ping 127.0.0.1 or ping ::1 to test the local computer. Ping –tis continuous, ping-n is a set amount of pings, and ping –l changes the size of each ping.
– Tracert: Sends packets to test destinations beyond the local computer’s network.
– Netstat: Shows the network statistics for the local computer. Displays TCP and UDP sessions by computer name (or IP) and port.
– NBTStat: Shows network protocol statistics that use NetBIOS over TCP/IP connections. Shows core services running on local or remote machines.
– NSLookup: Used to query DNS servers to find out DNS details including the IP address of hosts.
– Net: Used to map network drives (net use), view computers (net view), start/stop services (net start and net stop), and synchronize time (net time).
- No network connectivity?
– Check link light, patch cable, disabled NIC, wireless switch off (on laptops), IP configuration, and Windows Network Diagnostics.
– Ping localhost; then move outward and use ipconfig/all.
Poor wireless signal?
– Check distance, placement, antennas, and update hardware and software.
– IPconfig/release and /renew. Check DHCP server.
- Wireless encryption protocols include:
-WEP (Wired Equivalent Privacy), 64-bit key size. Deprecated.
– WPA (Wi-Fi Protected Access), version 2 is 256-bit.
– TKIP (Temporal Key Integrity Protocol), 128-bit. Deprecated.
– CCMP (addresses vulnerabilities with TKIP), 128-bit.
– AES (Advanced Encryption Standard), 128-bit, 192-bit, and 256-bit.
– Best combination is WPA2 with AES (as of this cramsheet).
- Malicious Software (Malware) includes the following:
– Virus: Code that runs on a computer with the user’s knowledge; it infects the computer when the code is accessed and executed.
– Worms: Much like viruses except that they self-replicate whereas a virus does not.
– Trojan Horse: Appear to perform desired functions but are actually performing malicious functions behind the scenes.
– Spyware: Type of malicious software that is either downloaded unwittingly from a website or is installed along with some other third-party software.
– Rootkit: Software designed to gain administrator-level access to the core of a system without being detected.
- Social Engineering: The act of manipulating users into revealing confidential information or performing other actions detrimental to the user. Know phishing, shoulder surfing, and tailgating!
- Authentication: The verification of a person’s identity – Helps protect against unauthorized access.
Broken down into:
1. Something the user knows (password or PIN).
2. Something the user has (a smart card or other security token).
3. Something the user is (biometric reading: fingerprint or retina scan).
4. Something a user does (signature of voice print).UAC (User Account Control) in Windows 7/Vista requires administrative login to perform higher tasks.
- Encryption: The act of changing information using an algorithm known as a cipher to make it unreadable to anyone except users who possess the proper “key” to the data.EFS (Encrypting File System): Encrypts one or more files or folders directly within the Properties page. Makes file appear green.
BitLocker: Encrypts an entire disk, available only on Windows 7 Ultimate/Enterprise and Vista Ultimate/Enterprise. Requires TPM.
- Hard Drive disposal: Clearing (drive to be reused in house), purging (sanitizing, ExampleoD 5220.22-M seven pass standard , degaussing) and destruction (pulverizing, drilling holes in platters).
- BIOS security includes supervisor and user passwords, drivelock passwords, disabling removable media, and setting the boot device priority to hard drive first.
- Permission inheritance: If you create a folder, the default action it takes is to inherit permissions from the parent folder. If you move a folder within the same partition, it retains the permissions. If you move or copy a folder to another partition, the (new) folder inherits from the new parent.
- Mobile Devices use: ARM CPUs, flash memory, multi-touch displays. Common OSs: Android (Open-source) and iOS (Closed-source). Applications downloaded from Google Play (Android) and App Store (iPhones/Apple products).
- GPS and Geotracking provide location information about mobile devices.
- Mobile devices connect to Internet via GPRS (cellular WWAN) and Wi-Fi (WLAN).
- Mobile device security: Screenlocks (patterns, PIN, or password), invalid attempt lockouts, remote wipes, remote backups, and antivirus.
Rooting and Jalbreaking: Removing limitations of Android and iOS to gain super-user capabilities.