A+ Certification Prep Course Study Digest · A+ Certification Prep Course Study Digest SD ... Study Digest for CompTIA A+ ... The /? switch is used after any command to display syntax

A+ Certification Prep Course Study Digest SD_APlus-900-001-1

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The following publication, A+ Certification Prep Course Study Digest, was developed by Global Knowledge Training LLC. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means without the prior written permission of the copyright holder.

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A+ Certification Preparation Study Digest 1 SD_APlus-900-001-1 © Global Knowledge Training LLC

Study Digest for CompTIA A+

CompTIA A+ 220-901 and 220-902

This study digest was designed to provide important and key information to take away from your A+

course. We recommend that you memorize and understand what is included in the study digest for

optimal success in preparing for your A+ certification exams. Please understand that a study digest is

just one component of your certification training path. When the study digest is coupled with additional

test preparation tools such as instructor-led training, assessment tests, and study guides, your chance

of success on the A+ examinations will increase.

Personal Computer Components

Port Specifications

USB – No more than 5 hubs between host and device and no more than 127 total devices, including hubs – Currently regarded as the highest speed for printing

o USB 1.0/1.1 – 1.5 Mbps (Low-Speed – 3 m cables), 12 Mbps (Full-Speed – 5 m cables)

o USB 2.0 – 480 Mbps (Hi-Speed – 40 times USB 1.1 – 5 m cables)

o USB 3.0 – 5 Gbps (SuperSpeed – ~3 m cables) – full-duplex new to 3.0

FireWire (IEEE 1394) – 4.5 m cable limit, allowing 16 daisy-chained cables totaling 72 m with powered repeaters and hubs and no more than 63 devices per bridgeable bus

o FireWire 400 (IEEE 1394a) – 100, 200, or 400 Mbps half-duplex

o FireWire 800 (IEEE 1394b) – 800 Mbps full-duplex – Also includes S1600 and S3200

Optical-drive Facts

-ROM indicates the disc is not able to be written to in the field

-R indicates the disc can be written to once and then only read from

-RW indicates the disc can be written to and erased repeatedly

CD: 700 MB data capacity (others available); 150 kBps 1X throughput

DVD: 4.7 GB data capacity; 1.35 MBps 1X throughput

Double-layer (DL) DVD capacity: 9.4 GB (8.5 GB actual)

DVD-RAM: writes and erases like a floppy or flash drive: without closing the disc

Blu-ray: 25 GB per layer data capacity; 4.5 MBps 1X throughput Global Knowledge

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Operating Systems

Command Notes – The /? switch is used after any command to display syntax and notes about the

command, including additional switches and their functions. A switch adjusts the output of the

command but does not change the fundamental operation of the command.

IPCONFIG – Use the /ALL switch to see, in addition to your IP address, how the IP address was attained and the MAC address the interface. Use the /FLUSHDNS switch to clear the local DNS cache in such cases as when the computer needs to be forced to look up the current IP address for a host and not use a now invalid address that was returned previously.

DIR – Use the /AH switch to list all files with the hidden attribute set.

RECOVER – Used to retrieve readable data from a defective disk (CompTIA claims it retrieves deleted files – not true in the real world)

REPLACE – Replaces selected files in one location with files of the same name from another

MD, RD, CD – Make, remove, and change directories (folders), respectively

SFC – System file checker – Checks the integrity of protected operating-system files; use with the /SCANNOW switch to perform the scan immediately on all protected system files; use /SCANFILE for a particular file; use /VERIFYONLY and /VERIFYFILE to check but not repair all files or a specific file, respectively

DEFRAG – The command-line version of Disk Defragmenter, used to clean up discontiguous files that have been written to multiple physical areas of the hard drive, especially when the computer is running more slowly over time

CLS – Clears a Command Prompt screen, including all scroll-back information, placing the user at a prompt with nothing else on the screen.

MSCONFIG – Starts the System Configuration Utility, which along with REGEDIT (allows editing of the Registry), is one of the two methods to change the processes that start automatically (the startup environment), especially when unwanted processes are slowing the system

MSINFO32 – Starts the System Information Utility, which allows you to display a large amount of information about hardware, software, and resources; as does DXDIAG, displays your system’s BIOS version

NTBACKUP – Backs up or recovers data from an unencrypted file system

NBTSTAT – Displays statistics about NetBIOS over TCP/IP (NBT)

NSLOOKUP – Allows you to choose the DNS servers you query while at the command line

Other Windows commands to know: TASKKILL, BOOTREC, SHUTDOWN, TASKLIST, XCOPY, ROBOCOPY, DISKPART, FORMAT, CHKDSK, GPUPDATE, GPRESULT, EXTRACT

Linux commands to know: ls, grep, cd, shutdown, pwd vs. passwd, mw, cp, rm, chmod, cmkdir, chown, iwconfig/ifconfig, ps, q, su/sudo, apt-get, vi, dd

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Windows-key Shortcut Combinations

Windows-key – Open The Start Menu

Windows-key + E – Open My Computer

Windows-key + D – Show Desktop

Windows-key + M – Minimize All Windows

Windows-key + L – Lock desktop while unattended (faster than CTRL-ALT-DELETE Lock Computer)

Windows-key + F – Open Search

Windows-key + F1 – Open Windows Help

Windows-key + R – Open Run Dialog

Windows-key + U – Open Utility Manager

Windows-key + PAUSE Key – Open System Properties

File and Folder Permissions

File Permissions

Folder Permissions

List Folder Contents

Read Read

Write Write

Read & Execute Read & Execute

Modify Modify

Full Control Full Control

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Best Practices for the PC Technician Professional

Classes of Fire for Which Extinguishers are Rated

A – Fires involving wood, paper, cloth, rubber, and many plastics

B – Fires involving flammable liquids and gasses, including grease

C – Fires involving energized electrical equipment or wiring, where the extinguishing agent must not be conductive

D – Fires involving combustible metals, such as sodium, potassium, lithium, magnesium, titanium, uranium, plutonium, calcium, zirconium, and others

Quick Hits for Dealing with Customers and Your Company

If a customer wants to provide additional information, don’t discourage it; guide the conversation to keep the focus and then summarize what the customer has said. Always remain in control of the conversation to maximize your ability to gather pertinent information in the most effective way possible. However, avoid interrupting the customer to do so; wait until a proper point in the conversation to interject.

If a customer is not explaining their problem in terms that lead to your full understanding, do not give up or resort to trying to figure out the problem yourself. Ask the customer to explain the problem again but use questioning (a form of active listening, along with empathizing, paraphrasing, and summarizing), to guide them in the direction you need.

When you have problems with a customer, avoid referring them to a different technician or your supervisor. Also, never place blame on the customer or other technicians. This includes when the customer is abusive as well as when the problem appears to be over your head. Your perseverance is the most valuable asset toward retaining the customer and turning the situation around. Stay with the customer by assisting to the level of your abilities and do not break contact with the customer until you confirm they are in contact with the next level of support.

Avoid involving a supervisor until you have confronted a coworker or attempted to assist with their remediation. However, direct customers to your supervisor or coworkers to theirs when they make a request of you that you are uncomfortable or unsure about granting due to your ethics or unfamiliarity with accepted practices.

Whenever you witness a coworker having issues with a customer, it is acceptable to insert yourself politely in the situation under the premise of wishing to add your own support as well. Do not dress down the coworker for their own conduct with the customer, especially in the customer’s presence.

As soon as you realize you will have trouble meeting an appointment with a customer, call and reschedule. Do not attempt to beat the clock to finish up a job or take care of an emergency with the hopes of making it on time. Doing so might make you late, while the customer has no warning of such a situation, as well as cause inferior performance or injury to you or others, due to your rushing.

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The only appropriate time to mention the way a customer is talking to you, about you, or about your company is when profanity is being used. Even then, request that the customer not use profanity and keep yourself engaged in the conversation, as opposed to bringing your supervisor into the situation or threatening to leave.

o Do not ignore a ranting customer to begin or resume work. Never fight fire with fire; keep your cool and try your best not to take things personally.

o At first, listen to the customer vent and then join the conversation when you see an opportunity to derive pertinent information or assure the customer that you will attempt to resolve their problem.

o However, never make closed-ended claims about how the situation will turn out or tout your abilities to get the job done this time around. Failure to deliver will only make the customer more irate and may tend to imply that your coworkers are inept. Statements of your intent or attempted resolution are acceptable.

Never insult the customer’s intelligence.

o If they do not understand something the way you are explaining it, control your frustration and find a way to explain things in language they will understand. This means avoid jargon and acronyms; put things in complete, concise terms that give the full picture without confusion.

o Avoid the other extreme as well; reading documentation to a customer is condescending, but getting closer or sitting next to the customer, within reason, can serve to ease the tension created by the communication gap.

o If a language barrier exists or if you are dealing with a deaf customer, avoid the temptation to bail and instead notify your supervisor of the situation and, without being condescending, attempt nonverbal communication to get your point across in the short term.

Use tact when educating a customer about the technical needs to change their behavior, such as reducing the amount of dust being introduced into the computer system. Stick to the technical impetus to do so and do not insult the customer’s work or living habits.

Remain as diplomatic as possible when speaking with customers about your company and those of your competitors. Do not resort to hyperbole to make your company look better or to slander to make the competition look worse. Politely inform customers and others that you are unable to discuss confidential information about your company. However, if the customer insists on talking about your company, discussing your policies and practices regarding services offered and customer satisfaction is certainly acceptable.

Always follow your company’s documented procedures. When unsure of procedures for a particular situation, ask your supervisor or other authoritative personnel. Technicians should always notify their supervisor when environmental hazards are discovered.

Ignore all incoming calls while working with or for a customer. Use voicemail as a tool to make sure callers realize that you might be busy and will return their call after you are available. However, calls or pages that are known to be emergencies or scheduled work calls that come in while with a customer should be handled with your quick return to the job at hand. Make sure to politely and professionally explain the situation to the customer beforehand and ask to be excused.

Never use or touch a customer’s property without a business need to their benefit and then, only with their permission. This includes not using their phone for personal calls and not answering their phone when it rings. This also includes asking the customer to clear the work area and not doing it yourself.

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Refrain from treating a customer’s family and friends as resources and from interacting with them directly to mitigate distractions. In other words, don’t ask acquaintances for assistance and don’t speak authoritatively to children or use psychology to try to make them behave. Do not try to physically remove them from the work area. Discipline is the responsibility of their guardian. Request, don’t demand, all of this of the customer and do not allow yourself to be left in a home alone with minors.

Concerning confidentiality and privacy, contact and notify the customer immediately if there are sensitive windows open on the computer or sensitive documents that you notice lying around the work area. Request that the customer secure such resources and, for computer-related incidents, lock the computer until the customer is able to comply; never take it upon yourself to close windows on a customer’s computer, which includes non-sensitive windows as well.

With internal or external customers, be a guardian of legal practices and accepted policy. If no crime has been committed yet, warn the customer of the laws regarding what they are asking you to do or what they intend to do. If a crime has been committed, notify law-enforcement officials to avoid becoming an accessory after the fact. For internal breaches in policy, inform the user of how they are in violation, again avoiding supervisor involvement. Along the same lines, avoid placing yourself in danger by not installing your own software on a client’s computer. Also, avoid installing freeware when the customer can purchase their own copy of a credible application that is more likely to completely meet their needs.

If you are responsible for answering incoming calls, before anything else, always identify yourself to a level that allows the customer to know whether they have reached the right contact. This includes your name, so that the customer knows who has helped them for future reference, and your department or group affiliation, so they know whether they have contacted or been transferred to the right place.

Act honestly and responsibly when dealing with customers. If you damage anything within the customer’s computer, do not try to cover it up. Admit your mistake and go through proper channels with your company to make things right with the customer.

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Installing and Configuring Peripheral Components

PCI Express (PCIe) – A serial (versus parallel, such as PCI and AGP) bus-slot that has an

architecture featuring multiple “lane” widths, such as x1 (by-one), x4, and x16 – Version 1 of PCIe

(don’t confuse with x1) ran each lane at 250 MBps each way (500 MBps total); x4 is four times this

fast; x16 is 16 times as fast – Version 2 is twice as fast as version 1 at each width; version 3 is twice

as fast as version 2, etc. – Often has a retaining clip at the rear that must be released for

removal

Computer-video Standards and Resolutions

VGA – 640 x 480 (4:3)

SVGA – 800 x 600 (4:3)

XGA – 1,024 x 768 (4:3)

SXGA – 1,280 x 1,024 (5:4)

UXGA – 1,600 x 1,200 (4:3)

WUXGA – 1,920 x 1,200 (16:10)

Quality of Video Interfaces – From highest to lowest

HDMI

DVI

Component

S-Video

Composite

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Installing and Configuring System Components

Memory Cards and Technologies Based on Solid-State Flash – Recognize the names

USB thumb/pen drives/USB keys

Solid-State Drives (SSD)

CompactFlash (CF) cards

SmartMedia cards (SM)

xD-Picture cards (xD)

Memory Stick (MS)

Secure Digital cards (SD), Micro-SD, Mini-SD

Embedded MultiMediaCard (eMMC)

Redundant Array of Independent Disks (RAID) – Hardware or software implementation that binds

separate physical drives together to function as one volume, whether for increased storage or for

redundancy – CompTIA once considered RAID 1 and RAID 5 to be the only fault-tolerant

implementations

RAID 0 – Striped set without parity – Non-redundant array – Minimum 2 drives

RAID 1 – Mirrored set without parity, called mirroring – Redundant controllers is called duplexing – Exactly 2 drives

RAID 5 – Striped set with distributed parity – Stripes of parity present on all disks – Minimum 3 drives

RAID 10 (1+0) – Two RAID 1 mirrored sets striped together using RAID 0, to increase overall capacity but maintain fault tolerance – Minimum 4 drives

MBR Drive Partitioning Rules on Basic Disks

A single physical hard drive on an NT-based system (non-Win 9x) today can have a total of 4 partitions, which are made up of primary and extended partitions.

There can only be one extended partition on any physical HDD.

An extended partition can contain numerous logical drives.

In order for a physical HDD to be accessible to the operating system, it must have at least one partition.

A bootable system must have at least one primary partition. That partition must be marked active.

Only one primary partition on a given physical HDD can be marked active at a time.

For a physical HDD, possible partition sets are (P=primary and E=extended): 4P, 3P, 3P1E, 2P, 2P1E, 1P, 1P1E. A 1E arrangement can only be used when no operating system will be installed.

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Only primary partitions and logical drives on extended partitions can have drive letters assigned to them or can be mounted in an empty NTFS folder (on the same or different physical HDD). This makes them accessible to the operating system as drives and allows them to be formatted with a file system. Extended partitions cannot have drive letters or be mounted in an empty NTFS folder; they can only contain logical drives.

Possible files systems for formatting primary and logical partitions include:

FAT16 – legacy and limited

FAT32 – from the Windows 98 era, but still supported for interoperability in multiboot systems

FAT64/exFAT – ideal for formatting USB drives

NTFS – default and recommended for its efficiency and security in all NT-based systems, starting with NT4 and continuing to today’s operating systems, excluding the Win 9x family.

Dynamic disks differ from basic disks in that they do not follow the partitioning rules above and can have any number of volumes, none of which are used to house bootable operating systems.

GUID Partition Table (GPT) – used to exceed MBR disks’ 2 TB maximum volume size and to more efficiently access large drive sizes

RAM Labels and Clock Speed – DDR and higher modules are named for their overall

throughput in MBps, the faster the frontside bus, the higher the throughput. Because throughput occurs 8 bytes (64 bits) at a time, it is 8 times the frontside-bus frequency. The chips on the modules are named for the frontside-bus speed. Some examples:

DDR with a FSB speed of 266 MHz uses DDR266 chips on PC2100 modules (266 x 8 = 2,133)

DDR with a FSB speed of 333 MHz uses DDR333 chips on PC2700 modules (333 x 8 = 2,667)

DDR2 with a FSB speed of 400 MHz uses DDR2-400 chips on PC2-3200 modules (400 x 8 = 3,200)

DDR2 with a FSB speed of 667 MHz uses DDR2-667 chips on PC2-5300 modules (667 x 8 = 5,333)

RAM Pin Counts

SDR SDRAM – DIMM: 168 pins – SODIMM: 144 pins

DDR SDRAM – DIMM: 184 pins – DDR/DDR2 SODIMM: 200 pins

DDR2/DDR3 SDRAM DIMM: 240 pins – DDR3 SODIMM: 204 pins

RIMMs – 16-bit: 184 pins – 32-bit: 232 pins

Chipsets – Control the transfer of data between the motherboard and the computer’s peripherals

Northbridge for devices capable of “local-bus” speeds (including the southbridge)

o Controls the frontside bus (FSB) and backside bus (BSB – optional)

o FSB interconnects CPU, RAM, cache (when BSB is not present), and PCIe video

o BSB, when present, interconnects CPU and cache

Southbridge for devices not capable of “local-bus” speeds

o Controls I/O bus interconnections, such as PCI, ISA, parallel, serial, USB, etc.

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Important Sockets and CPUs to Know

Knowing speed ranges is important. There aren’t many slot formats, so know them, too.

Socket or Slot CPUs Supported LGA 775 (Socket T) Pentium 4, Pentium D, Celeron D, Pentium

Extreme Edition (dual core), Core 2, Xeon, Celeron E Series

LGA 1155 (Socket H2) Celeron G4 and G5 Series

LGA 1156 (Socket H) Celeron (G1xxx series), Core i3, Core i5, Core i7 (8xx series), Pentium (G6xxx series), Xeon (34xx series)

LGA 1366 (Socket B) Core i7 (9xx series), Xeon (35xx, 36xx, 55xx, 56xx series), Intel Celeron P1053

LGA 1150 (Socket H3) Xeon, Pentium, Celeron, Core i3, Core i5, Core i7

LGA 2011 (Socket R) Higher-end CPUs than LGA 1150, DDR3, DDR4

Socket AM3 AMD DDR3-capable CPUs

Socket AM3+ AMD Bulldozer architecture

Socket FM1 AMD Fusion APUs (CPU/GPU fusion)

Socket FM2 AMD Athlon X2, Athlon X4

Socket FM2+ AMD Steamroller architecture; fits FM2 chips

Installing and Configuring Operating Systems

Windows Upgrade Lists

Windows Vista: wikipedia.org/wiki/Windows_Vista_editions

Windows 7: wikipedia.org/wiki/Windows_7_editions

Windows 8: wikipedia.org/wiki/Windows_8_editions

Requirements for Installing Windows 7 and Windows 8

1 GHz or faster 32-bit (x86) or 64-bit (x64) processor

1 GB RAM (32-bit) or 2 GB RAM (64-bit)

16 GB available hard disk space (32-bit) or 20 GB (64-bit)

DirectX 9 graphics device with WDDM 1.0 or higher driver

For more options and links, see wikipedia.org/wiki/Windows_7#System_requirements and

wikipedia.org/wiki/Windows_8#Hardware_requirements

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Requirements and Recommendations for Installing Windows Vista

1 GHz x86 or x64 processor

1 GB of RAM

Hard disk: 40 GB with 15 GB of free space

Support for DirectX 9 graphics

DVD-ROM drive

Audio output

Internet access

Keyboard and mouse

Windows Vista (and later) Special Files Used during Boot

BOOTMGR – Accesses the Boot Configuration Data store – Analogous to the combined function of NTLDR and BOOT.INI in older NT-based operating systems

BCD – In the BOOT folder at the root of the system drive – Is the Boot Configuration Data store

Services – Processes that run in the background to provide functionality beyond the OS kernel –

Can be set for Automatic, Manual, or Disable – Disable is the only setting that prevents a service from starting

Start Control Panel Administrative Tools Services

Start Control Panel Administrative Tools Computer Management Services & Applications Services

Start Run type SERVICES.MSC

Use the Services Snap-in within the Microsoft Management Console (MMC)

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Key File Locations

Root of User Files (User Profile appends username folder to these)

Vista/7: Users

System Root (Windows Directory): Windows

64-bit System Files and 32-bit System Files on x86 Systems: %SystemRoot%\System32

32-bit System Files on x64 Systems: %SystemRoot%\SysWOW64

64-bit Program Files on x64 Systems and 32-bit Program Files on x86 Systems: Program Files

32-bit Program Files on x64 Systems: Program Files(x86)

Installed-font Files: %SystemRoot%\Fonts

Temporary Files (when present, user overrides system)

System: %SystemRoot%\Temp

User (Vista/7): %UserProfile%\AppData\Local\Temp

x64 Folder Naming: http://tinyurl.com/yahclgd

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Maintaining and Troubleshooting Microsoft Windows

Event Viewer – Allows viewing and clearing of log files generated by Windows or applications

Accessing Event Viewer

o Start Programs Administrative Tools Event Viewer (if turned on through Taskbar Properties)

o Control Panel Administrative Tools Event Viewer (always works)

Types of Logs

o Security – Logs events related to account logon events, object access, privilege use (such as logging on locally), and system events

o System – Logs events related to operating-system functions, such as DHCP-client results, Network Time synchronization results, the starting and stopping of services, driver initialization during boot, Windows Browse events, device errors, and Windows Update progress

o Application – Logs events related to applications installed on the computer, including events that require a system restart, application licensing events and status, etc.

Types of Backup Jobs

Daily – Backs up only files that changed on or after the date specified when performing the backup; does not change the backup marking from its original value

Copy – Backs up only files you select, regardless of whether they have changed since the last backup; does not change the backup marking from its original value

Incremental – Backs up everything that has changed since the latest backup (normal or incremental only) and then marks each file as backed up

Differential – Backs up everything that has changed since the latest backup (normal or incremental only) but does not mark the files as backed up, which makes them part of the next backup (differential or incremental) as well

Normal/Full – Most complete and time-consuming; required before either an incremental or differential backup can be performed – Backs up everything, regardless of whether it changed since it was last backed up and marks each file as backed up

Notes on Recovery Options – Attempt the following in order when system instability dictates

1. Roll Back Driver – Use when you know which driver has been updated and is causing the instability – Run from the device’s Driver tab under its Properties pages – Does not require the operating system’s setup disc

2. Last Known Good Configuration (LKGC) – Use when you are not able to log on to Windows successfully, even in Safe Mode – After a successful logon, this option will not work because the instability has been cached in the LKGC – Run from the Windows Advanced Options menu by pressing F8 during boot – Does not require the operating system’s setup disc

3. System Restore – Run when you know of a recent time when the instability did not exist but cannot pinpoint the driver causing the problem and LKGC is not an option – Run from Accessories System Tools – Does not require the operating system’s setup disc

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4. Automated System Recovery (ASR) – Run as a last resort – Will always resolve the instability, but data loss is likely without a recent user-data backup – Must be run by pressing F2 to break into the setup process that installs the operating system from its distribution media

Networking Computers

Wireless Specifications

Infrared Data Association (IrDA) – A short-range technology for temporary wireless links

o 3.3’ (1 m) maximum range within a 30-degree cone, longer when aligned directly

o 16 Mbps maximum rate

Bluetooth – 2.4 GHz – A short-range cord-replacement radio system for semi-permanent accessory links, often involving small intelligent devices and common peripherals – Most popular technology for wireless keyboard and mouse attachment

o Class 1 – 100 mW, 100 m (300 ft)

o Class 2 – 2.5 mW, 10 m (30 ft)

o Class 3 – 1 mW, 1 m (3 ft)

o Version 1 – 1 Mbps



Satellite Internet – 16 Mbps maximum – Line-of-site required

802.11 – Indoor range: 35-38 m (70 m for 802.11n); outdoor range: 120-140 m (250 m for 802.11n) – Fastest wireless access method

o 2.4 GHz interference caused by microwave ovens leaking a similar RF frequency (lunchtime when break room is near the WAP), 2.4 GHz cordless phones, Bluetooth, baby monitors, and amateur radio

o Ad-hoc mode includes no access points; infrastructure mode includes access points.

o Default behavior is to connect to any available network (access point preferred)

o 802.11n uses single-user (SU) MIMO and the frequencies and modulations of a/b/g to maximize speed. Supports up to four 150-Mbps spatial streams (600 Mbps maximum, 450 Mbps common, depending on whether 40 MHz combined channels are being used).

o 802.11ac uses MU-MIMO and only a 5 GHz radio. Supports up to 8 spatial streams, at 433.3 each, but tops out around 1,300 Mbps, due to a limit of 3 streams per user.

11 Mbps 54 Mbps 600 Mbps 1,300 Mbps

2.4 GHz 802.11b 802.11g 802.11n

5 GHz 802.11a 802.11ac

WiMAX (802.16) – Wireless metropolitan area network (MAN), 70 Mbps or more

Basic Network Topologies: Bus, Ring, Star, Mesh, Point-to-point

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Five Classes of IP Address and Default Masks

Unicast: A – 0 through 127 (/8); B – 128 through 191 (/16); C – 192 through 223 (/24) D (multicast) – 224 through 239; E (experimental) – 240 through 255 (D & E: no mask)

Special-use IP Addresses – None of these are allowed across the Internet

Private – May be used by anyone because they are not allowed across the Internet

o 10.0.0.0 through 10.255.255.255

o 172.16.0.0 through 172.31.255.255

o 192.168.0.0 through 192.168.255.255

Loopback: 127.0.0.1 – For testing the successful installation of the TCP/IP stack – No network traffic is generated.

APIPA: 169.254.0.0 through 169.254.255.255 – For auto-configuration when dynamic address assignment is configured, but a DHCP server cannot be found

Common Protocols with TCP and UDP Port Numbers – TCP and UDP are transport-layer

protocols. TCP provides guaranteed delivery through acknowledgements, while UDP provides best-effort delivery without the overhead of acknowledgements. TCP is connection-oriented; UDP is not.

HTTP (TCP port 80) – Any question that mentions web browsing; HTTPS, port 443

FTP (TCP ports 20 and 21) – Most common protocol for exchanging data over the Internet

Telnet (TCP port 23) – Used to remotely configure a host through a terminal window

DNS (TCP and UDP port 53) – Used for accessing Internet resources by name more than for accessing LAN resources

SNMP (TCP ports 161 [agent] and 162 [traps]) – Network management protocol for monitoring and making automatic changes across the network to network elements (such as networking components and printers) running agents that are under the control of a high-end management workstation – Must be installed on both the computer acting as the management workstation and the network element under its control

SMTP (TCP port 25) – Used for sending e-mail

POP3 (TCP port 110) – Used for retrieving e-mail from the server

IMAP4 (TCP port 143) – Used instead of POP3 to access e-mail from multiple locations, leaving messages on the server for later viewing or deletion. Web-based e-mail services, such as Hotmail, that allow you to access your mail from several locations do not use IMAP; they use HTTP.

NAT (no port number; not a client/server protocol) – Converts private addresses used on the internal network to public addresses that are allowed to be routed on the Internet. Adds security by not allowing Internet hosts to detect internal address structure and by preventing them from making the initial contact; they can only respond to contact initiated by internal hosts.

Terminal Services (TCP port 3389) – Used by RDP with Remote Desktop Connection

SMB and CIFS (UDP ports 137, 138; TCP ports 139, 445) – Windows file sharing; CIFS is newer

AFP (TCP ports 548 or 427) – Apple Filing Protocol; used in Mac OS X for file sharing

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Laptops and Portable Computing Devices

PC Card (PCMCIA) Specifications

Type I

o 3.3 mm thick o Typically used for memory devices

Type II

o 5 mm thick o Typically used for modem, network, TV cards, and cards with miniature interfaces that

require dongles

Type III

o 10.5 mm thick o Typically used for hard drives and cards with full-size interfaces

32-bit CardBus has gold strip on insertion end

PC Cards (and MiniPCI) are based on PCI and USB 1.1; ExpressCards (and Mini-PCIe) are based on PCIe and USB 2.0 and can be 34 mm or 54 mm wide (ExpressCard/34 and ExpressCard/54).

Supporting Printers

Study the printer Unit in your courseware book and familiarize yourself with the names and details of the steps in the laser printing process, starting or ending with the Cleaning phase. However, consider the Erasing phase to be part of the Cleaning phase. Review printer troubleshooting in the Sybex book.

Personal Computer Security

Types of Malicious Software – Study the types of malicious software and familiarize yourself with

the names and details of these security threats, especially viruses, worms, and Trojan horses.

Turning on the Windows Firewall

1. Right-click My Network Places Properties

2. Right-click the connection on which you would like to enable the firewall Properties.

3. On the Advanced tab, click the box to select the option to “Protect my computer or network. “

WEP Key Lengths

WEP keys include a 24-bit initialization vector that is not part of the numerical key.

64-bit keys have 40 bits left that must be represented by 10 hex digits.



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Security Threats – The best defense to those threats not able to be controlled with software is the

education of personnel to be aware of such attacks and the policies to observe before releasing sensitive information. Users should be made aware of forms of official contact that they can expect and the types of information that will be asked for as well as the types that will never be asked for. Data defense is not required for information that is public domain, such as that which can be found on a corporate website.

Social Engineering – Using assumed private, yet socially attainable, information to deceive others into providing truly private information or services. Examples include the following:

o A phishing e-mail (which all users should be trained to delete) that appears to be from a credible source, such as a bank or internal administrators, and that requests username and password details from a customer or user

o One phone call to the assistant of a director or other executive, obtaining name and schedule for a particular day, only to follow up that call with another to the IT department, requesting a password change after guessing the executive’s username. For this reason, common formats for usernames, including jdoe and johnd for John Doe, should be avoided, and IT personnel should implement PINs or a requirement for other information that cannot be guessed by attackers.

Spoofing – Making data appear to come from somewhere that it did not

Secure Areas – Some installations, both military and civilian, have secure areas where you must be escorted at all times. Unfortunately, your escort will be required to remain with you the entire time you are working. If you need the user’s credentials to log on to the system one or more times, the user will also be required to remain with you because you are not allowed to know this private information.

Mobile Devices

Testable Operating Systems – Google Android, Apple iOS, and Windows Phone

Screen Orientation and Locating – Know these meanings and be able to differentiate.

Accelerometer – detects linear motion (forward/back, up/down, left/right)

Gyroscope – detects angular motion: pitch (dip), yaw (roll), and rotation

Magnetometer – detects compass headings

GPS – detects longitude, latitude, and elevation by communicating with three or four satellites

Cellular network – works with or in place of GPS to locate the device or its user (for marketing)

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E-mail Configuration – Know the following TCP port numbers used for e-mail and its security.

SMTP

o Port 25 – insecure and secure, using SSL o Port 465 – secure, using SSL o Port 587 – secure, using TLS

POP3

o Port 110 – insecure o Port 995 – secure, using SSL or TLS

IMAP4

o Port 143 – insecure o Port 993 – secure, using SSL or TLS

Synchronization – Know the most common types of data that is synchronized.

Contacts

Programs (Apps)

E-mail

Pictures

Music

Videos

Custom Configurations

Graphic / CAD/CAM Design Workstation

Multicore CPU

High-end video

Maximum RAM

Audio/Video Editing Workstation

Specialized audio and video cards

Large fast hard drive

Dual monitors

Virtualization Workstation

Maximum CPU cores

Maximum RAM

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Gaming PC

Multicore CPU

High-end video/specialized GPU

High-definition sound card

High-end cooling

Home Theater PC

Surround sound audio

HDMI output

HTPC compact form factor

TV tuner card

Standard Thick Client

Desktop applications

Meets recommended requirements for running Windows

Thin Client

Basic applications

Meets minimum requirements for running Windows

Network connectivity

Home Server PC

Media streaming

File sharing

Print sharing

Gigabit NIC

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Documents

A+ Certification Prep Course Study Digest · A+ Certification Prep Course Study Digest SD ... Study Digest for CompTIA A+ ... The /? switch is used after any command to display syntax