A+ 701 Cram Sheet
A+ 701 Cram Sheet
A+ 701 Cram Sheet
Dot Matrix
• An impact printer that transfers characters by striking a pattern
(from a matrix) through an inked ribbon and onto paper.
• The most common number of pins on a dot matrix printer is 9, 18,
or 24.
• The speed of dot matrix printers is measured in characters per
second (CPS). Common speeds for a dot matrix printer are 32 to
72 CPS.
• Dot matrix printers can use either a friction feed or a tractor feed
system to move paper through the printing assembly.
• Because dot matrix printers strike the image onto paper, it is a
4. Developing: Image is developed by attracting positive toner onto
good printer to use when carbon-copy documents are being
drum.
printed.
Solid Ink
• Solid ink printers melt ink onto the print head (which is as wide as
the paper). The head jets the melted ink onto the paper as the
paper passes by on the print drum (similar to the laser printing Language Description
process).
• The head takes as long as 15 minutes to heat prior to printing. Escape Codes Used to control dot matrix printers.
Hewlett-Packard has created several versions of a
Thermal Printer Control
printer control language called PCL. Many modern
• A thermal printer is a non-impact printer that uses heat to cause a Language (PCL)
printers understand PCL.
reaction on specially treated paper.
Adobe created a printer language called PostScript
• Monochrome thermal paper is chemically treated to darken where
PostScript that easily handles scaling of certain fonts and
heated (photosensitive). Many cash registers use this type of
images.
printer for creating receipts.
• Colour thermal paper is chemically treated to absorb colour from
a ribbon where heated. Troubleshooting Printers
• Ink is applied via the ribbon in a similar manner to a solid ink If the printer prints, but the printout quality is poor, check the following:
printer. • Check ribbon, ink, and toner levels.
• The colour system used by thermal printers is CMYK (Cyan, o For dot matrix printers, printer images become faint when
Magenta, Yellow, and black). the ribbon needs to be replaced. Also, ensure that there isn’t
• The paper must make one pass for each application of a different too much of a gap between the printer head and the paper.
colour. o For inkjet printers, if letters have missing lines, use the
• Colour thermal printers are very expensive, high quality, and printer's automatic cleaning feature. If this doesn't work,
operate quietly. replace the printer cartridge. For missing or incorrect
colours, verify ink levels.
Printer Configuration Facts o For laser printers with missing lines, try shaking the toner
Print Server: is responsible for managing the flow of documents from cartridge to distribute the toner evenly. If lines are still
the queue to the printer. When the printer is ready, the print server missing, or if extra characters appear, you might need to
takes the next document out of the queue and sends it to be printed. have the printer cleaned or some internal components
replaced.
Printer: A virtual device (logical software entity) inside the print server • For laser printers:
that can be configured to send output to a printing device. The printer o A dirty primary corona wire can cause a vertical stripe down
is made up of the print driver, the printing device, and the spooler. the print job because that part of the OPC drum is not being
charged by the charge corona.
Print Device: The physical device connected to the print server where o A dirty secondary corona wire could cause the same
print output occurs. problem because the charge is not being applied to part of
the paper.
Print Driver: The software that allows the printer to communicate with o If toner is not sticking to the paper, check the transfer rollers.
the print device. Printer drivers provide the following support functions: o A faulty static eliminator strip might cause paper jams
• Translate data into a recognizable form for the given printer. because the paper will stick to the components inside the
• Manage graphics via graphics drivers, converting graphics into printer.
the appropriate printer commands. • For newer laser and inkjet printers, calibrate the printer (perform a
• Allow management of the print job by displaying print and printer self test). Calibration fixes blurry text or incorrect colours.
properties in the operating system. • If the text appears garbled, make sure the proper printer driver is
used.
When a print job is sent to the printer, the printer driver: • If the page only prints part way through (and the rest of the page
1. Formats the print job and creates a file of commands the printer is blank), you might need to upgrade the memory on the printer or
understands. The file is in a specific format called a printer check the print server settings.
language (also called page-description languages). • Check the pickup rollers; if paper is not being fed through the
2. The file is then sent to the printer where it is stored in the printer's printer properly.
memory.
3. The printer's formatter board and control circuitry then read the Scanners
commands in the file and translate them into physical actions by • Scanners use a light source and a Charge-Coupled Device (CCD)
the printer. that captures light and converts it to digital data.
• Twain is a scanner language that bridges the different scanners to
Print Queue: The portion of the hard drive where print jobs are stored a common form that can be interpreted by typical graphics
before going to the print device. software applications.
Print Spooling: In print spooling, documents are loaded into a buffer Below is a typical scanner and its components
(usually an area on a disk), and then the printer pulls them off the
buffer at its own rate. Because the documents are in a buffer where
they can be accessed by the printer, the user is free to perform other
operations on the computer while the printing takes place in the
background. Spooling also lets users place a number of print jobs in a
queue instead of waiting for each one to finish before specifying the
next one.
All parallel connections must adhere to the IEEE standard 1284. You
should look at your printer configuration to see which mode your printer
requires. The five modes addressed in the IEEE standard are: Serial, Parallel IEEE 1284 & PS/2 Components
• Nibble Connector Description
• Compatibility Serial Connector
• BYTE • The maximum length for an RS-232
• EPP serial cable is 50 feet.
• ECP
RAID 1: mirrored set (min 2 disks) w/o parity. Provides fault tolerance Self Powered
from disk errors and single disk failure. Devices that rely on their own power supply (in other words, you plug
them into an AC outlet) are called self-powered devices. All devices
RAID 3 & RAID 4: striped set (min 3 disks) w/ dedicated parity. This that draw more than 500 mA of power are required to be self-powered.
mechanism provides an improved performance and fault tolerance
similar to RAID 5, but with a dedicated parity disk rather than rotated Bus Powered
parity stripes. USB cables have wires to carry both power and data. Bus-powered
devices get their power from the USB cable. Bus-powered devices are
RAID 5: striped set (min 3 disks) w/ distributed parity. Distributed classified as low-powered or high-powered devices depending on the
parity requires all but one drive to be present to operate; drive failure amount of power they draw from the USB bus.
requires replacement but the array is not destroyed by a single drive • Low powered devices use 100 mA or less
failure. • High-powered devices use between 100 and 500 mA
Like USB devices, USB hubs can be bus-powered or self-powered.
RAID 6: striped set (min 4 disks) w/ dual distributed parity. Provides You cannot connect high-powered devices to a bus-powered hub (you
fault tolerance from two drive failures; array continues to operate with can only connect low-powered or self-powered devices to a bus-
up to two failed drives. powered hub). Therefore, self-powered hubs that provide 500 mA per
port are recommended to ensure an adequate power supply to all bus-
PC Card Types powered devices that you may wish to connect to the hub.
Service Set Identification (SSID): The SSID identifies a network and Protocols
logically groups all devices onto a single network. The SSID is Protocol Description
commonly referred to as the network name. HTTP is used by Web browsers and Web servers to
exchange files through the World Wide Web and
Wireless Equivalent Privacy (WEP): WEP is an encryption mechanism HyperText intranets. HTTP can be described as an information
designed to provide wireless networks the same type of protection that Transfer requesting and responding protocol. It is typically used to
cables provide on a wired network. Only users with the correct WEP Protocol (HTTP) request and send Web documents, but is also used as
key are allowed to authenticate. the protocol for communication between agents using
different TCP/IP protocols.
Wi-Fi Protected Access (WPA): WPA is a security mechanism that HyperText
attempts to address the weaknesses of WEP by assigning unique keys Transfer
to each host and changing the dynamic keys periodically. WPA offers Protocol over
greater protection than WEP. HTTPS is a secure form of HTTP that uses SSL as a sub
Secure Socket
layer for security.
Layer or HTTP
Infrared (IrDA) over SSL
• Infrared uses invisible light waves for communication. (HTTPS)
• Is a line-of-sight medium. HTML is a data format that is used to create hypertext
• Communicates at 9600 bps up to 4 Mbps and uses the resources documents that can be viewed from multiple platforms.
of a COM port. HyperText
Although HTML is not technically a programming
• Works best for devices within 1 meter, but can operate up to 30 Markup
language, it has become a common language used for
meters in areas without ambient light interference Language
programming information in a format that is readable by
(HTML)
web browsers. It consists of a series of tags that define
Bluetooth the attributes of displayed text and images.
• Bluetooth uses radio waves for communication. SSL secures messages being transmitted on the
• Uses ad hoc connections between devices to create personal Internet. It uses RSA for authentication and encryption.
area networks called piconets. A piconet can have up to 7 Secure Sockets
Web browsers use SSL (Secure Sockets Layer) to
devices, and each device can participate in multiple piconets at Layer (SSL)
ensure safe Web transactions. URLs that begin with
the same time. https:// trigger your Web browser to use SSL.
• Operates in the 2.4 GHz frequency range and uses adaptive FTP provides a generic method of transferring files. It
frequency hopping (AFH). It automatically detects other devices in can include file security through usernames and
the area and avoids the frequencies used by those devices. It can passwords, and it allows file transfer between dissimilar
switch between 79 channels to avoid interference. File Transfer computer systems. FTP can transfer both binary and text
• Transmits at up to 3 Mbps. The maximum distance depends on Protocol (FTP) files, including HTML, to another host. FTP URLs are
the device class: preceded by ftp:// followed by the DNS name of the FTP
o Class 3 devices transmit up to 1 meter. server. To log in to an FTP server, use:
o Class 2 devices transmit up to 10 meters. ftp://username@servername.
o Class 1 devices transmit up to 100 meters. SMTP is used to route electronic mail through the
• Class 2 devices are the most common. internetwork. E-mail applications provide the interface to
• Can be used for both voice and data signals. Simple Mail
communicate with SMTP or mail servers. SMTP is a
Transfer
relatively simple, text-based protocol, in which one or
Troubleshooting Networks Protocol
more recipients of a message are specified (and in most
If the connection shows that the cable is unplugged, check the status (SMTP)
cases verified to exist) and then the message text is
indicator lights on the network card. transferred.
• The link light indicates a valid connection to the network. Internet IMAP is an e-mail retrieval protocol designed to enable
users to access their e-mail from various locations Communication between hosts on a network generally takes one of
Message without the need to transfer messages or files back and three forms:
Access Protocol forth between computers. Messages remain on the • Simplex: one-way communication from a sender to a receiver.
(IMAP) remote mail server and are not automatically • Half-duplex: two-way communication between two hosts.
downloaded to a client system. Communication only travels in one direction at a time.
POP3 is part of the TCP/IP protocol suite and used to • Full duplex: two-way communication between hosts.
Post Office Communication can travel in both directions simultaneously.
retrieve e-mail from a remote server to a local client over
Protocol 3
a TCP/IP connection. With POP3, e-mail messages are
(POP3)
downloaded to the client. Address Range Default Class Default Subnet Mask
Telnet allows an attached computer to act as a dumb
Remote 1.0.0.0 to 126.255.255.255 A 255.0.0.0
terminal, with data processing taking place on the
Terminal 128.0.0.0 to 191.255.255.255 B 255.255.0.0
TCP/IP host computer. It is still widely used to provide
Emulation
connectivity between dissimilar systems. Telnet can also 192.0.0.0 to 223.255.255.255 C 255.255.255.0
(Telnet)
be used to test a service by the use of HTTP commands.
SSH allows for secure interactive control of remote 224.0.0.0 to 239.255.255.255 D Multicast
Secure Shell
systems. SSH is a secure and acceptable alternative to 240.0.0.0 to 255.255.255.255 E Reserved
(SSH)
Telnet.
Can’t contact
DHCP is a protocol used by networked computers to 169.254.0.1 to 169.254.255.254 DHCP server, 255.255.0.0
Dynamic Host
obtain IP addresses and other parameters such as the APIPA
Configuration
default gateway, subnet mask, and IP addresses of DNS
Protocol
servers from a DHCP server. The DHCP server ensures
(DHCP) 127.0.0.1 is a special purpose address reserved for use on each
that all IP addresses are unique.
computer. 127.0.0.1 is conventionally a computer's loopback address.
DNS is a system that is distributed throughout the Network software and utilities can use 127.0.0.1 to access a local
internetwork to provide address/na computer's TCP/IP network resources. Messages sent to loopback IP
Domain Name
me resolution. For example, the name addresses like 127.0.0.1 do not reach outside to the local area network
System (DNS)
www.mydomain.com would be identified with a specific (LAN) but instead are automatically re-routed by the computer's own
IP address. network adapter back to the receiving end of the TCP/IP stack.
The suite of communications protocols used to connect
TCP/IP
hosts on the Internet. UTP Cable Types
Programs on networked computers can send short Type Connector Description
messages sometimes known as datagrams (using
Datagram Sockets) to one another. Datagrams may Phone RJ-11 Used to connect a modem to a phone jack in a wall
User Datagram arrive out of order, appear duplicated, or go missing cable outlet to establish a dial-up Internet connection.
Protocol (UDP) without notice. Avoiding the overhead of checking Has two pairs of twisted cable (a total of 4 wires).
whether every packet actually arrived makes UDP faster Cat 3 RJ-45 Designed for use with 10 megabit Ethernet or 16
and more efficient, at least for applications that do not megabit token ring.
need guaranteed delivery.
Cat 5 RJ-45 Supports 100 megabit and 1 gigabit Ethernet and
IPX/SPX is the protocol suite used on legacy NetWare
ATM networking.
networks.
• NetWare 3 and NetWare 4 use IPX/SPX by default. Cat 5e RJ-45 Similar to Cat 5 but provides better EMI protection.
However, both can be configured to use TCP/IP. Supports 1 and 10 gigabit Ethernet (gigabit
IPX/SPX connections require the use of all four twisted
• One way to configure a Microsoft client computer to
connect to a NetWare server running IPX/SPX is to pairs).
install the NWLink protocol software supplied by Cat 6 RJ-45 Supports high-bandwidth, broadband
Microsoft. communications.
AppleTalk is the protocol suite used by early Apple
Macintosh computers. Twisted Pair & Coaxial Cables
AppleTalk
• AppleTalk over IP is the protocol for using Appletalk
on a TCP/IP network Connector Description
NetBIOS is the term used to describe the combination of • Has 4 connectors
two protocols: Because NetBIOS is a non-routable RJ-11 • Supports up to 2 pairs of wires
protocol, it was often combined with TCP/IP or IPX/SPX • Uses a locking tab to keep connector
NetBIOS
to enable internetwork communications. secure in outlet
• NetBEUI is the native protocol of Windows • Used primarily for telephone wiring
3.x/95/98/ME.
• Has 8 connectors
WINS provides a centralized method of name RJ-45 • Supports up to 4 pairs of wires
management that is both flexible and dynamic. A WINS
Windows
server automatically collects entries whenever a client is • Uses a locking tab to keep connector
Internet Name secure in outlet
configured with that WINS server’s address. In theory, if
Service (WINS) • Used for Ethernet and some token
DNS is available, WINS is only necessary if pre-Windows
2000 clients or servers need to resolve names. ring connections
• Twisted onto the cable
Network Address Translation (NAT) F-Type
• Used to create cable and satellite TV
NAT refers to network address translation involving the mapping of connections
port numbers, allowing multiple machines to share a single IP address. • Used to hook a cable modem to a
broadband cable connection
Networking Utilities
NSLOOKUP.EXE: enables you to verify entries on a DNS server. BNC
• Molded onto the cable
PING.EXE: Sends a series of packets to another system, which in turn • Used in 10Base2 Ethernet networks
sends back a response. This utility can be extremely useful for
troubleshooting problems with remote hosts. AUI
• DB15 serial connector
TRACERT.EXE: enables you to verify the route to a remote host. The
• Used in 10Base5 Ethernet networks
results also include the number of hops needed to reach the
destination router.
Multi-mode and single mode fiber cables are distinct from each other Internet Connectivity
and not interchangeable. The table below describes multi-mode and Method Description
single mode fiber cables.
PSTN is an example of a circuit switched technology.
Type Description Each time a call is placed, it is assigned the next
• Transfers data through the core using a single light ray available connection pathway to the other party. This
(the ray is also called a mode) connection is lost at the end of the call. PSTN Internet:
Single •
• The core diameter is around 10 microns Uses a single POTS (Plain Old Telephone Service)
Mode phone line with a modem.
• Supports a large amount of data
• Cable lengths can extend a great distance • Uses a single channel on the line.
PSTN (Public • Has common data transfer rates include 28.8 Kbps,
• Transfers data through the core using multiple light rays Switched 33.3 Kbps, 56 Kbps.
Multi-
• The core diameter is around 50 to 100 microns Telephone • Offers sufficient network connectivity for a minimal
mode
• Cable lengths are limited in distance Network) investment.
• Is available virtually anywhere that regular voice
Fiber Optic Connector Types grade communications are available.
Type Description • Requires the destination host's phone number
(username and password are required at log on) for
• Used with single and multi- configuring a dial-up connection.
mode cabling • Cannot be used for voice and the Internet
• Keyed, bayonet-type concurrently.
connector
• Also called a push in and DSL is a newer broadband digital service provided by
twist connector telephone service providers that operates using digital
signals over regular telephone lines. DSL Internet:
• Each wire has a separate
• Comes in many different varieties (such as
ST Connector connector
ADSL and HDSL).
• Nickel plated with a ceramic
ferrule to insure proper core • Sends digital signals over existing copper
alignment and prevent light telephone wire using multiple channels.
ray deflection DSL (Digital • Has one channel that is dedicated to phone line
Subscriber data, with additional channels used for data.
• As part of the assembly
process, it is necessary to Line) • Can be used for voice and the Internet
polish the exposed fiber tip concurrently.
to ensure that light is • Requires a DSL router (or a cable modem) or NIC
passed on from one cable to attached (with USB or Ethernet) to the phone line.
the next with no dispersion • Requires filters (also called splitters) before the
phone with some implementations.
• Used with single and multi- • Requires a location to be within a fixed distance of
mode cabling network switching equipment.
• Push on, pull off connector
type that uses a locking tab ISDN ISDN is a digital service, running over a switched
to maintain connection (Integrated network. ISDN Internet:
• Each wire has a separate Services Digital • Uses a switched network which includes 4-wire
SC Connector Network) copper telephone lines in a local loop and standard
connector
• Uses a ceramic ferrule to telephone lines.
insure proper core • Establishes a virtual circuit through dial-up before
alignment and prevent light communication (on-demand service).
ray deflection • Supports most upper-level protocols
• As part of the assembly (communication protocols allow all media types to
process, it is necessary to transmit over the same line at high speeds).
polish the exposed fiber tip Levels of service include:
BRI (Basic Rate Interface):
LC Connector • Used with single and multi- o 2 64-Kbps bearer (B) channels can transfer
mode cabling data up to 128 Kbps (data compression
• Composed of a plastic increases the data transfer rate). Only one B
connector with a locking tab, channel is used during phone use reducing
similar to a RJ-45 connector maximum speed to 64 Kbps.
• A single connector with two o 1 16-Kbps delta (D) channel for connection
ends keeps the two cables control.
in place
o Often called 2B + 1D.
o Suitable for periodic bursts of data.
PRI (Primary Rate Interface):
• 23 B channels (each at 64 Kbps) for data
transmission.
o 1 D channel (at 64 Kbps) for connection
control.
o Often called 23B + 1D.
o Is not available in all service areas;
subscribers are required to be within a certain
proximity of telephone company equipment.
Cable Internet uses the extra bandwidth on cable
television connections. Cable Internet:
• Uses a high-speed bi-directional channel connected
Cable directly to an Internet Service Provider (ISP) Application Layer 7:
through cable TV lines. Responsible for providing network services—like file services,
• Uses a cable modem to convert analog signals over print
multiple channels. services, and messaging services (not applications like word
Satellite Internet service providers offer nearly 100% processing or spreadsheets, as the layer's name might lead
global network coverage where there is a local network you to believe).
infrastructure. Satellite Internet: Network Component:
Gateway
• Requires a local portable transmitter with an
antenna (dish) directed skywards to a satellite.
Satellite • Requires direct line of sight (dish placement is Presentation Layer 6:
crucial). Responsible for the presentation of data (for example, the
• Is subject to mild atmospheric and weather translation of character sets—e.g., ASCII to EBCDIC).
conditions (fog or slight wind can disrupt service). Network Component:
• May have a long delay time (latency) between Gateway, Redirector
requests and downloads.
Session Layer 5:
Wireless Internet offers continuous network access Responsible for establishing and maintaining a
through strategic placement of Wireless Access Points. communications “session.” IP and IPX operate at this layer.
Wireless Internet:
Wireless Network Component:
• Broadcasts openly and can be easily detected (data Gateway
encryption is advisable).
• Availability is increasing
Transport Layer 4:
A cellular WAN is the network that is used to make Responsible for providing reliable end-to-end communications.
cellular telephone calls. If you install a cellular WAN Includes most of the error control and flow control. TCP and
adapter to your notebook or desktop system, you can SPX operate at this layer.
Cellular WAN connect to the Internet through the cellular WAN Network Component:
wherever a signal is available. Use this option to provide Gateway, Brouter
Internet access in remote areas (as long as a cellular
signal is available).
Network Layer 3:
Voice over Internet Protocol (VoIP) sends voice phone Responsible for translating logical network addressing and
Voice-Over-
calls using the TCP/IP protocol over digital data lines. their names to their physical address. Some error control and
Internet
VoIP solutions typically combine voice and data over the flow control is performed at this level. DNS, FTP, SNMP, SMTP
Protocol (VoIP)
same lines, allowing both to be used together. and Telnet operate at this layer.
Network Component:
Firewalls Gateway, Advanced Cable Tester, Brouter, Router
A firewall is a network device installed on the border of secured
networks that acts as a barrier between your computer or private Data Link Layer, Layer 2:
network and another network such as the Internet. The firewall This layer really has two separate layers; Logical Link Control
examines incoming traffic and allows only the traffic that meets & Media Access Control. Responsible for the logical topology
predetermined criteria. and logical (MAC) addressing. Individual network card
addresses also function at this level.
Network Firewall: A network firewall monitors and filters the activity of Network Component:
all computers hooked up to a network. Bridge, Switch, ISDN Router, Intelligent Hub, NIC
• A firewall is created by installing two interfaces on a central
network device: one interface connects to the private network, Physical Layer 1:
and the other interface connects to the external network. Responsible for placing the network data on the wire, by
changing binary data into electrical pulses on the physical
Host-based Firewall: A host-based firewall monitors and filters the medium. The physical topology is defined at this level.
activity of a single computer. Network Component:
• Firewall software is installed on a single system that is connected Hubs (Passive, Active), Transceivers, Amplifiers
to the Internet through a modem, network, cable modem, or DSL
line. Network Components
Repeaters: allow a cabling system to extend beyond its maximum
allowed length by amplifying the network voltages so they travel
farther. Repeaters are nothing more than amplifiers and, as such, are
very inexpensive.
Hubs: are devices used to link several computers together. There are
two types of hubs: active and passive. Passive hubs connect all ports
together electrically and are usually not powered. Active hubs use
electronics to amplify and clean up the signal before it is broadcast to
the other ports. In the category of active hubs, there is also a class
called intelligent hubs, which are hubs that can be remotely managed
• copy [source] [destination] copies the specified file to
on the network.
the new location.
• copy [folder] [*.*] [path] [destination] copies all files
Switches: operate very similarly to hubs because they connect several
with extensions in a folder to the new location.
computers. However, switches don’t repeat everything they receive on
one port to every other port as hubs do. Rather, switches examine the • copy /n copies files using short filenames.
header of the incoming packet and forward it properly to the right port • copy /y will not prompt you before each deletion.
and only that port. • copy /v verifies files after they are copied.
Use the xcopy command to copy files and directory trees.
Bridges: join similar topologies and are used to divide network Common switches used with xcopy are:
segments. Bridges keep traffic on one side from crossing to the other. • xcopy /a copies files with the archive attribute set and
doesn't change the attribute.
Routers: are highly intelligent devices that connect multiple network • xcopy /m copies files with the archive attribute set and
types and determine the best path for sending data. They can route turns off the archive attribute.
packets across multiple networks and use routing tables to store
• xcopy /d copies files changed on or after the specified
network addresses to determine the best destination.
date. If no date is given, it copies only those files whose
source time is newer than the destination time.
Brouters: They are used to connect dissimilar network segments and
• xcopy /p prompts you before creating each destination
also to route only one specific protocol. The other protocols are xcopy file.
bridged instead of being dropped. Brouters are used when only one
protocol needs to be routed or where a router is not cost-effective (as • xcopy /s copies directories and subdirectories (except
in a branch office). empty ones).
• xcopy /e copies directories and subdirectories,
including empty ones.
Gateways: connect dissimilar network environments and architectures.
Gateways convert data and repackage it to meet the requirements of • xcopy /h copies hidden and system files also.
the destination address. • xcopy /r overwrites read-only files.
• xcopy /k copies attributes. Normal xcopy will reset
Command Line Utilities read-only attributes.
• xcopy /y overwrites existing files without prompting.
Command Description
Use the edit command to view, create, or modify files.
Converts a drive from FAT or FAT32 to NTFS w/o losing any
Common switches used with edit are:
convert data
edit • edit [file] specifies initial files(s) to load. Wildcards and
• convert C: /fs:ntfs
multiple file specs can be given.
Use the cd command to work with the current directory. • edit /r load file(s) in read-only mode.
Common switches used with cd are:
The IPCONFIG command checks your computer’s IP
• cd by itself shows the current directory (the current configuration.
directory is usually showed in the command prompt as • /all shows full configuration information
well). ipconfig • /release releases the IP address, if you are getting
• cd [folder name] changes the current directory to the addresses from a DHCP server
cd one specified (if the directory is within the current • /renew obtains a new IP address from a DHCP server
directory). • /flushdns flushes the DNS name resolver cache
• cd [full path] changes to the directory specified by the
path.
Memory Types
• cd .. changes the current directory to the immediate
parent directory (moves up one directory level). 72-pin SIMM
• cd /D [file] [path] changes the current drive in addition
to changing the directory.
Use the dir command to display a list of files and
subdirectories in a directory. Common switches used with dir
are:
• dir /p pauses output at every page.
168-pin SDRAM (Synchronous Dynamic RAM)
• dir /s display information in subdirectories.
dir
• dir /a[xx] display files with the specified attributes:
o Options may be combined, such as /arh, to show
read-only, hidden files.
o Use - to show files without an attribute. For
example, dir /a-r shows files that are not read only.
Use the md command to create (make) a directory. Common 184-pin RDRAM (Rambus DRAM)
switches used with md are:
md • md [directory] creates a new directory in the current
mkdir directory.
• md [path] [directory] creates a new directory in the
directory specified by the path.
Use the rd command to delete (remove) a directory. 184-pin DDR (Double-Data Rate Synchronous Dynamic RAM)
Common switches used with rd are:
• rd [directory] removes the specified directory within the
current directory.
rd • rd [path] [directory] removes the directory specified in
the path.
• rd /s removes subdirectories in addition to files in the
current directory. 240-pin DDR-2
• rd /q will not prompt you before each deletion.
copy Use the copy command to copy files from one location to
another. Common switches used with copy are:
Shadow Mask: consists of a metal screen full of holes that are aligned
with each dot. The screen shields the electron beam from illuminating
between dots and leaves an outline around each pixel.
Refresh Rate: The refresh rate is the amount of time required for the
CRT's electron beam to paint the screen from top to bottom.
200-pin SODIMM Interlacing: Interlacing is drawing the screen in two passes; even lines
on the first and then the odd lines on the second pass. Non-interlaced
monitors produce the least amount of flicker.
Note: CRT monitors have a 4:3 aspect ratio which matches the display
ration of a television set.
Monitors
CRT Monitor Facts
Screen Size: The physical screen size or actual size is the diagonal
measure of the display tube.
Viewing Size: identifies the largest image size that can be displayed.
Because of how the CRT monitor works, portions of the display tube
cannot be used for displaying the image.
Female
HD connectors (also called
Micro DB or HP (half pitch)) are
HD (high density) used for both internal and
external SCSI-2 and SCSI-3
devices. Intel Celeron - Socket 370 AMD XP - Socket 462 or A
• 50-pin connectors are
Male used for 8-bit data
transfer.
• 68-pin connectors are
used for 16-bit data
transfer. These
Female connectors are about 1/2
inch larger than the 50-pin
connectors.
VHD (very high density) AMD Opteron - Socket F AMD Athlon 64 X2
VHD connectors have 68-pins
and are smaller than the HD
Male connectors. VHD connectors
are often used in SCSI cards
and are sometimes called
SCSI-5 connectors.
Female
Security
Virus: is a program that attempts to damage a computer system and
replicate itself to other computer systems.
• Requires a host to replicate and usually attaches itself to a host
file or a hard drive sector.
• Replicates each time the host is used.
• Often focuses on destruction or corruption of data.
• Usually attaches to files with execution capabilities such as
.doc, .exe, and .bat extensions.
• Often distributes via e-mail. Many viruses can e-mail themselves
Throttling: Throttling is the process of modifying the operating
to everyone in your address book.
characteristics of a processor based on current conditions.
• Throttling is often used in mobile processors to change the Worm: is a self-replicating program that can be designed to do any
operating frequency to minimize power consumption and heat number of things, such as delete files or send documents via e-mail. A
output. worm can negatively impact network traffic just in the process of
• Throttling can also be used in low memory conditions to slow replicating itself.
down the processing of I/O memory requests, processing one • Can install a backdoor in the infected computer.
sequence at a time in the order the request was received.
• Is usually introduced into the system through a vulnerability.
• Infects one system and spreads to other systems on the network.
Hyper-threading: Hyper-threading is a feature of some Intel processors
that allows a single processor to run threads in parallel, as opposed to
Trojan horse: is a malicious program that is disguised as legitimate
the older and slower technology of processing threads linearly.
software. Discretionary environments are often more vulnerable and
susceptible to Trojan horse attacks because security is user focused
Overclocking: Overclocking is a feature that causes the processor to
and user directed. Thus the compromise of a user account could lead
operate at a higher speed.
to the compromise of the entire environment.
Multi-processor: two (or more) processors on the motherboard. • Cannot replicate itself.
• Often contains spying functions (such as a packet sniffer) or
Multi-core Processor: multiple processor cores integrated into a single backdoor functions that allow a computer to be remotely
processor package. controlled from the network.
• Often is hidden in useful software such as screen savers or
Processor Size: The process size refers to the manufacturing process games.
used to etch transistors onto the silicon wafer that will become the
CPU. A smaller process size means smaller transistors, which Logic Bomb: is malware that lies dormant until triggered. A logic bomb
translates into a smaller CPU die with more transistors and less power is a specific example of an asynchronous attack.
consumption. Process size is expressed in microns (such as .25 • A trigger activity may be a specific date and time, the launching of
microns) or nanometers (90 nm which equals .09 microns). a specific program, or the processing of a specific type of activity.
• Logic bombs do not self-replicate.
Voltage Regulator Module (VRM): The VRM is an electronic device
that supplies the appropriate voltage to a processor; thus allowing Spyware: monitors the actions you take on your machine and sends
multiple processors with different voltage requirements to be mounted the information back to its originating source.
on the same motherboard. A VRM can either be an installable device • Spyware is a program that is installed on your machine by visiting
controlled through the BIOS, or soldered directly to the motherboard a particular webpage or running a particular application.
and controlled by the processor. Installable VRMs are more common in • Some spyware intercepts sensitive information.
dual processor and server systems.
Adware: monitors the actions of the user that would denote their
ESD personal preferences, then sends pop-ups and ads to the user that
Electrostatic Discharge (ESD): Static electricity is the accumulation of match their tastes.
an electric charge (produced by friction) on a non-grounded object. • Is usually passive.
The static charge on the surface of a non-grounded object can jump • Is a program that is installed on your machine by visiting a
when it contacts the surface of any grounded object. particular webpage or running a particular application.
• Is usually more annoying than harmful.
Catastrophic failures: cause components to fail. The only solution for a
failed component is to replace it. Grayware: is a term used to describe any application that is annoying
or negatively affecting the performance of your computer. If an
Upset failures: degrade components, leading to ongoing or intermittent application doesn’t fall into the virus or Trojan category, it can get
problems or eventual failure. With these types of failures, it is difficult to lumped under grayware. Spyware and aware are often considered
identify the source of the intermittent problem or even know if damage types of grayware, as are programs that log user keystrokes and
has occurred. certain hacking programs.
Precautions against ESD include: Spam: is sending unwanted e-mail messages. Spam can become a
• Use antistatic mats under the PC and on the floor. form of DoS attack because:
• Discharge yourself before touching any computer component. • It consumes bandwidth that is used by legitimate traffic.
• When touching anything inside the computer, wear an antistatic • It can fill a mailbox or hard disk and result in legitimate e-mail
wrist strap that is attached with an alligator clip to the metal PC being rejected.
chassis. • Spam is often distributed by hijacking misconfigured SMTP
• Ground both yourself and the computer to the same ground. This servers.
provides a single path for the flow of electrical potential.
• Use static resistant materials to handle computer components. Social Engineering
• Never touch the metal connectors on a circuit board. Social engineering exploits human nature by convincing someone to
• Avoid dry air in the computer repair location. reveal information or perform an activity. Examples of
• Keep computer repair location free of materials that accumulate social engineering include:
electric charges (for example, plastic or Styrofoam). • Impersonating support staff or management, either in person or
• Store sensitive components in static shielded bags (usually tinted over the phone.
gray). Static resistant bags are not near as effective (usually • Asking for someone to hold open a door rather than using a key
tinted pink or blue). for entrance.
• If a wrist strap is unavailable, keep your body in constant contact • Spoofed e-mails that ask for information or ask for tasks to be
with the metal frame when working inside the computer. performed (such as delete a file or go to a Web site and enter
• Keep the relative humidity high (over 70%). sensitive information).
• Looking on desks for usernames and passwords. Unlike user rights, security options are either enabled or
disabled for everyone. Examples of Security Options
Attack Description policies include:
Security
• Computer shut down when Security event log
Dumpster diving is the process of looking in the trash for Options
reaches capacity
Dumpster diving sensitive information that has not been properly
disposed of. • Unsigned driver installation
• Ctrl+Alt+Del required for log on
Shoulder surfing involves looking over the shoulder of
Shoulder surfing
someone working on a laptop.
Authentication
Piggybacking refers to an attacker entering a secured
Piggybacking Threat Description
building by following an authorized employee.
Sniffing is an inside attack in which someone connects to the
Masquerading refers to convincing personnel to grant
network and captures all of the packets that are transmitted
access to sensitive information or protected systems by
over a network. They then use a sniffing program to
pretending to be someone who is authorized and/or
rearrange the packets so they can see all of the information
requires that access.
Masquerading Sniffing being transmitted. The best ways to prevent sniffing are:
• The attacker usually poses as a member of senior
• Install software packages that can detect sniffing.
management.
• Don't use clear-text passwords. Be especially careful
• A scenario of distress is fabricated to the user to
with FTP, TELNET, and LDAP servers because they
convince them that their actions are necessary.
commonly transmit in clear text.
Eavesdropping refers to an unauthorized person
Password cracking is a serious threat to your system. There
Eavesdropping listening to conversations of employees or other
are many different tools that attackers can use to break into
authorized personnel discussing sensitive topics.
a password-protected system. If a password is successfully
Phishing uses an e-mail and a spoofed Web site to gain cracked by an unauthorized user, they can alter your current
sensitive information. password settings and then login into your system as an
• A fraudulent message that appears to be legitimate administrator. The best way to prevent password cracking is
is sent to a target. to never use the default usernames or passwords provided
Phishing • The message requests the target to visit a Web Password by a system, especially on administrator accounts. A strong
site which also appears to be legitimate. cracking password policy typically:
• The fraudulent Web site requests the victim to • Requires passwords 8 characters or longer (longer
provide sensitive information such as the account passwords are stronger).
number and password. • Prevents the use of the username or a dictionary word
(or common variations) in the password.
Security Settings • Requires the use of numbers and symbols.
• Forces periodic password changes and prevents the
Setting Group Description
use of previous passwords.
The password policy defines characteristics that valid
Lurking is a security threat that entails a user walking around
passwords must have. Settings that you can configure in
a workplace and casually recording the usernames and
the password policy include:
passwords being entered on office computers. This is done
• Requiring passwords to have a minimum length. by either watching over someone's shoulder as they login or
• Forcing users to change passwords at regular by searching through personal notes or reminders that may
Password Lurking
intervals. include usernames and passwords. To help prevent
Policy
• Requiring complex passwords (password that contain successful lurking, you should use long, complex, passwords
numbers, symbols, upper- and lower-case letters). that are changed frequently. Train your users to use
• Preventing users from changing passwords too passwords that are not easily guessed and don't contain any
quickly. information that is indicative of the user.
• Not allowing users to reuse previous passwords.
Use account lockout settings to protect user accounts from There are alternative authentication systems available to improve your
being guessed and to also prevent accounts from being security:
Account used when hacking attempts are detected. For example, a • Smart cards are cards that contain a memory chip with encrypted
Lockout common setting is to lock the user account when three authentication information that allows a user access to facilities in
Policy consecutive incorrect passwords have been entered. the office. Smart cards can:
Locked accounts cannot be used for logon until they are o Require contact such as swiping or they can be contactless.
unlocked or until a specific amount of time has passed. o Contain memory chips similar to swipe cards, but with more
Auditing (also referred to as logging) is an operating data.
system feature that records user and system actions. Use o Contain microprocessor chips with the ability to add, delete,
the audit policy to identify the types of actions and events and manipulate data on it.
you want to track. For example, you can enable auditing to o A smart card can store digital signatures, cryptography keys,
Audit Policy and identification codes.
monitor all logon attempts. When a user logs on,
information about the logon will be recorded in the • A biometric system attempts to identify a person based on metrics
Security event log. Use Event Viewer to view information or a mathematical representation of the subject's biological
about audit events. attribute. This is the most expensive and least accepted, but is
generally considered to be the most secure form of
User rights determine what actions a user can perform on
authentication. Common attributes used for biometric systems
a computer or domain. User rights settings identify users
are:
or groups with the corresponding privilege. Examples of
o Fingerprints (end point and bifurcation pattern)
user rights include:
o Retina scans (blood vein pattern)
• Access this computer from the network (the ability to
access resources on the computer through a network o Iris scans (colour)
User Rights connection) o Facial scans (pattern)
Assignment • Allow log on locally (the ability to log on to the o Palm scans (pattern, including fingerprints)
computer console) o Hand topology (side view) or geometry (top down view)
• Allow log on through Terminal Services (the ability to o Voice recognition
log on using a Remote Desktop connection) o Handwriting dynamics
• Back up files and directories (does not include o Keyboard or keystroke dynamics (behavioral biometric
restoring files and directories) systems)
• Shut down the system
Fire Extinguishers
Class A extinguishers are for ordinary combustible materials such as Good communication skills are essential when communicating with
paper, wood, cardboard, and most plastics. The numerical rating on customers and colleagues. This includes being tactful and using
these types of extinguishers indicates the amount of water it holds and discretion. Some things to remember about communication skills are:
the amount of fire it can extinguish. • Use clear, concise, and direct statements.
• Allow the customer to complete statements--avoid interrupting.
Class B fires involve flammable or combustible liquids such as • Clarify customer statements--restate what they have said and ask
gasoline, kerosene, grease and oil. The numerical rating for class B pertinent questions.
extinguishers indicates the approximate number of square feet of fire it • Avoid using jargon, abbreviations, and acronyms.
can extinguish. • Actively listen to customers.
Class C fires involve electrical equipment, such as appliances, wiring, Another important aspect of acting in a professional manner is to treat
circuit breakers and outlets. Class C extinguishers do not have a your customers with respect. This includes always providing
numerical rating. The C classification means the extinguishing agent is confidentiality, using caution when entering a customer's workspace or
non-conductive. working on their computer, and never treating a customer in a
demeaning manner. Some other important things to remember about
Class D fire extinguishers are commonly found in a chemical dealing with your customers in a respectful manner are:
laboratory. They are for fires that involve combustible metals, such as
• Maintain a positive attitude and tone of voice.
magnesium, titanium, potassium and sodium. These types of
extinguishers also have no numerical rating, nor are they given a multi- • Avoid arguing with customers or becoming defensive.
purpose rating - they are designed for class D fires only. • Realize the importance of your task--do not minimize customers’
problems.
• Avoid being judgmental, insulting, or calling the customer names.
• Avoid distractions or interruptions when talking with customers.
You should attempt to resolve all customer problems yourself as long
as the task falls within your scope of responsibility. If a request is
outside of your ability or your responsibility, help the customer get in
contact with the appropriate people (such as another technician who
handles those requests or a manager who has the authorization to
respond to a problem or a request).
Windows Utilities
Event Viewer: Use Event Viewer to view logs about programs, system
events, and security. Each entry is listed as a warning, error, or
information event. Events are added to the following logs:
• The Application log contains a list of all application-related events
such as application installations, un-installations, and application
errors.
• The System log contains a list of all system-related events such
as system modifications, malfunctions, and errors.
• The Security log contains a list of all security-related events such
as security modifications and user login events.
CHKDSK: An MS-DOS utility you can use to scan and repair both FAT
and Windows NT NTFS volumes.
Professionalism Facts
Check Disk: Check Disk is a utility that verifies the file system integrity automatically flags the file as needing to be archived. When the file is
of a hard disk. Errors that can be checked and fixed by Check Disk backed up, the backup method may reset (clear) the archive bit to
include: indicate it has been backed up.
• Lost clusters--series of clusters on the hard disk drive that are not
associated with a specific file. Resets Archive
• A cross-linked file occurs when two files claim the same cluster. Backup Type Backs Up
Bit?
Check Disk will identify cross-linked files and correct their cluster
associations. Backs up all files regardless of the
Full Yes
You can run Check Disk by typing chkdsk at a command prompt. Use archive bit.
chkdsk with the /f switch to automatically fix errors. Note: Check Disk Backs up files on which the archive bit is
replaces the ScanDisk utility that was available in Windows 9x/Me. Incremental Yes
set.
Backs up files on which the archived bit
SCANREG: allows you to back up and verify the integrity of the Differential No
is set.
registry.
Backs up all files regardless of the
Copy No
WINNT32.EXE: The executable you use to re-install or upgrade archive bit status.
Windows 2000 on a computer that already has Windows 95, 98, or NT
installed. Registry Facts
The registry is a database that holds hardware, software, and user
WINNT.EXE: The executable you use to install Windows 2000 on a configuration settings. The registry is composed of the following
computer that does not have a previous version of Windows 95, 98, or components:
NT installed.
Component Description
System Restore Facts A key is a logical division or grouping of values in the
System Restore is a component of Windows XP that is used to restore registry. A key contains subkeys and values. The top-layer
a computer to a previous state. System Restore monitors the actions keys in the registry are:
on a system and saves restore at regular intervals and also before a • HKEY_CLASSES_ROOT contains associations of
change that could potentially affect the system is made. The different programs and file types, and configuration data for
types of System Restore points are: COM objects.
• HKEY_CURRENT_USER contains the profile, or
System restore: points are automatically made every 24 hours. configuration information for the user currently logged
on to the computer, including desktop folders, screen
Application installation restore: points are made before a new colors, and Control Panel settings. It is important to
application is installed. Only applications that are specially designed Keys and remember that this file is very dynamic.
will trigger the restore point creation process. subkeys • HKEY_USERS contains settings for all of the user
profiles on the computer. The
Restore operation: restore points are made every time you initiate a HKEY_CURRENT_USER key is an alias for a key
system restore. This makes it possible for the system to revert to the inside this subtree.
state it was in before you initiated a system restore in the following
• HKEY_LOCAL_MACHINE contains configuration
situations:
information for the computer itself, which applies to all
• You don't like the results from a system restore and wish to users.
cancel the restore that you initiated.
• HKEY_CURRENT_CONFIG contains information
• A restore is unsuccessful and System Restore must automatically about the hardware profile that the computer uses at
revert to the previous restore point. startup. Portions of this subtree come from the
HKEY_LOCAL_MACHINE subtree.
Unsigned driver: install points are made each time before a new driver
is installed or updated. Installing a signed driver will not cause a Every key in the registry contains values. Values consist of
restore point to be made. a value type, a name, and the value data. Value types are:
• String value
Manual restore: points are created by the user through the System Values • Binary value
restore wizard. • D-word value
• Multi-string value
Be aware of the following when using System Restore: • Expandable-string value
• System Restore does not affect files in My Documents or e-mail
accounts, so manual backups will still need to be made of all A hive is a group of keys, subkeys, and values within a
personal files. specific set of files. While registry-editing utilities display the
registry as a single entity, the various values are actually
• System Restore requires a minimum of 200 MB of disk space. If
saved in different hives. Examples of hives include:
that much disk space is not available, System Restore will be
disabled. It will be enabled automatically once the minimum disk • HKEY_LOCAL_MACHINE\Security
space is available. • HKEY_LOCAL_MACHINE\Software
• When disk space available to System Restore is used, older • HKEY_LOCAL_MACHINE\System
restore points will be deleted, making room for new restore points. • HKEY_CURRENT_CONFIG
The filenames of the files saved in the registry are:
ASR Facts Hive • SAM
Automated System Recovery (ASR) is a last-resort method of backing • Security
up and restoring the operating system. Use the ASR Wizard in the • Software
Windows Backup Utility (NTBACKUP) to create the ASR backup. The • System
process does the following: • Default
• Backs up operating system information to a backup set. • UserDiff
• Creates an ASR diskette. This diskette contains information • NTUSER.dat (located in
regarding disk partitions and volumes and other information WINDOWS\SYSTEM32\CONFIG\SYSTEMPPROFILE
necessary to restore the backup set. in Windows XP). The User.dat file contains user-
specific registry settings.
Note: An ASR should only be attempted after your backups and
system restore points have failed; ASR should never be your primary
In Windows NT/2000/XP, Regedt32.exe and Regedit.exe are both
means of disaster recovery.
included, but only Regedt32 allows you to apply security restrictions to
configuration settings.
Backup and Restore Facts
Most backup methods use the archive bit on a file to identify files that
Surge Protectors
need to be backed up. When a file is modified, the system
Here are some specifications which are critical to understand when
choosing a surge protector.
• Clamping voltage - This says what voltage will cause the metal
oxide varistors (MOVs) to conduct electricity to the ground line. A
lower clamping voltage indicates better protection. There are
three levels of protection in the UL rating -- 330 V, 400 V and 500
V. For most purposes, a clamping voltage more than 400 V is too
high.
An off-line UPS remains idle until a power failure occurs, and then
switches from utility power to its own power source, almost
instantaneously.