Studying for test
- You might want to
go over the POST codes, SCSI types, LCD aspect ratios. Also, what files are needed
to install XP, and what files will be found in the root directory of XP. Go over
the operating system upgrade paths. Go over 802 project models, OSI model. What is CSMA/CD? CSMA/CA?
Review fiber optic connectors.
- Also, firewalls, program
filtering, port filtering.
“Numbers" You Should Know
- 1294 parallel port.
1394 Firewire. 802.11x where x=a, b, g, or n (proposed) Wireless. A
is 5gHz. Others are 2.4. 802.3 ethernet.
and BIOS Operations
- IRQ’s http://www.helpwithpcs.com/upgrading/change-irq-settings.htm
- IRQ assignment.
First are the BIOS-configured IRQ’s.
- IDE primary 14,
secondary 15. LPT1, LPT2, are 7, 5. Floppy is 6. Com 1 and 3 are 4,
2 and 4 are 3. See pg http://www.helpwithpcs.com/upgrading/change-irq-settings.htm
- See Device Manager
> View Resources by Connection, or see Programs >Accessories
> System Tools > System Info.
- See http://www.pagesbydave.com/GEO/APLUSQUEST1.HTML#DDD
- XT systems had only
IRQ numbers from 0-7. Had a single irq chip. AT system added second
chip, 8 more hardware interrupts. On AT they made IRQ 2 on the first
chip, a gateway to cascade to the interrupts on the second chip,
and interrupts 8-15. The second interrupt on the second chip, IRQ 9,
cascades from the third interrupt on the first chip, IRQ 2. Originally
IRQ 2 was used for VGA. Now VGA uses 9? My Device manual says 9 is for
ACPI (Advanced configuration power interface). My gigabyte Sys Info
screen says that 9 is SCSI-RAID host controller and that the video card
is IRQ 16. However generally, don’t manually config 2 or 9.
IRQ priority: originally lower to higher (0 to 7). Now second chip replaces
IRQ 2, so sequence is now 0, 1, 8, 9, 10, 11, 12, 13, 14, 15, 3, 4,
5, 6, 7. Lower numbers have higher priorities. This is in contrast to
scsi priorites, where higher numbers tend to have higher priorities.
- Check out IRQ number
for a particular computer at device manager, or System Info. Look for
resources. On gigabytemb, acpi and scsi-raid share IRQ 9.
- IO memory addresses,
also called port address, or IO ports, are used for io access by a device,
rather than for storage of data. Ea address is a 32 bit number. 8 nibbles;
4 bytes. Each nibble is 4 bits. Each byte is 8 bits. 8 hexadecimal digits.
Ea hex digit represents a nibble, 2 hex digit represents a byte. First
4 hex digits are zero. So to remember the address for each port, you
only have to remember the last 4 hex digits of each port. (That means
highest possible port number is FFFFh, 65535 in decimal – 650k bytes).
IO address ranges have starting points and ending points (just 8 or
so larger than starting point). Just a small range for IO. Not the same
as mapping memory, which is a relatively large area of computer memory
used as a buffer by the peripheral. A periphal may use both,
an IO address, and buffer addresses. See book page 617.
- Decimal, hexadeximal,
binary. 4 binary digits equal 1 hex digits. So 2 hex digits equal an
Operating System Comparisons
- Only NTFS partitions
support file encryption and folder encryption. Copy such a file from
ntfs to fat32 and it will lose its encryption. Same with re to compression.
- File cannot be both
encrypted and compressed. However an encrypted file moved or copied
to compressed folder, becomes compressed.
- Fat32 uses smaller
cluster size than FAT 16 (also called FAT).
- Fat16 supports max
partition size of 2 gb. Restricts number of entries in root folder.
- FAT32 supported
by win 95, 98, osr2, ME, 2000, and xp. NT and linux can not be
on fat 32. Fat 32 max 8 terrabytes.
- FAT16 and FAT32
permits folder sharing NTFS supports file-level security.
- Linux reads FAT16
and ntfs but not fat32?
- Floppies use FAT12
|Win NT4.0 w sp4
- Hardware requirements
for various Op Sys
- For XP you need
a pentium and cpu operating at min 233Mhz recommended 300 Mhz
- Interestingly win
2000 pro needs Pent 2
- RAM 64 mb is very
minimum, 128 mb recommended.
- Free hard disk space
1.5G or more.
- XP requires a 2
gb hard drive and 650 mb of disk space. RAM 64 mg recommend 128. VGA
800 x 600 or better.
will check your hardware. It is on the installation cd.
- CD ROM or DVD ROM.
- SuperVGA or better.
(800 x 600). Mouse.
- Vista needs 1 ghz
processor. RAM 512 mb. 20 g hard drive with 15 g space.
- DirectX 9 graphics
and 32 MB of graphics memory
- Admin acct and password
is set up during gui mode of op sys install.
- Win 9x has io.sys,
msdos.sys, config.sys, command.com, autoexec.bat
- Windows 9x. multiboot
config determned by msdos.sys
- NT and XP and 2000
require ntldr (no extension!), boot.ini, ntdectect.com – in root directory
(of “system” partition, really the boot partition.)
- Booting the op sys:
- File invloved:
- A file called ntldr, in the the root directory, accesses the
file system on the boot drive.
- If file named hiberfil.sys is found in the root directory (hiberfil.sys is a hibernation image), its contents are loaded
into memory and the system resumes where it left off.
- Otherwise, the op sys reads
boot.ini and if prompts the user to make a choice from the boot menu. If there boot.ini has only one operating system listed, that sys can be configured so that the boot menu doesn't display, and the file for that system automatically gets loaded.
- If a non NT-based
OS is selected, then ntldr loads the file associated with the operating system chosen via boot.ini
(bootsect.dos if no file is specified or if the user is booting into
a DOS based OS) and gives it control.
- If an NT-based OS
(such as windows) is selected, then ntldr runs ntdetect.com,
which gathers information about the computer's hardware.
- If ntdetect hangs
during hardware detection there is a debug version called ntdetect.chk
which can be found on Microsoft support.
- Then ntldr starts
ntoskrnl.exe (usually c:\windows\system32\ntoskrnl.exe), passing to it the information returned by ntdetect.com.
- Windows 2000 network
protocols include appletalk, nwlink, netbeui.
- Nt has “disk administrator.”
- Ntfs, fat32, cdfs
- Virus cannot infect
a cd or dvd - by itself. However if a user unknowingly, or intentionally, burns a cd with a set of files that includes a virus, then the virus can obviously get onto the cd.
- Op sys upgrade paths.
See pg 271. 2000 you can upgrade to it from all but ME. XP, you can
upgrade from all but Win 95.
- Network install.
Boot to network. Boot from cd w net drivers then map net drive to share
that has installation files and then run winnt32 from there. Or
- Preboot execution
environment (if network card is pxe compatible) allows you to: when
booting you’ll see F12 to boot from network, this uses existing window
dhcp server to allocate address to network card then loads trivial ftp
service and others then downloads files automatically from predetermined
network share that’s been config with service for windows 2000 server
that will perform rest of installation for you. Bigger thruput than
even DVD. Fast. Unattended by using an sif file.
- File and application
data wizard works for config for multiple users?
- Upgrade as
opposed to full installation, retains program etc.
- Barts boot disks: http://nu2.nu/bootdisk
- You can boot from
win98 then sw cd’s to win xp cd and run winnt32 from that. DOS smartdrv
(RAM cache) will make install go faster.
- Whatever name you
put in during installation is legally liable re licensing issues!
- Network settings:
custom settings. Domain setting rarely works from client computer network
setting screen. Use peer workgroup instead.
- Automated and Remote
- Remote Installation
Services. RIS. Connect to 2003 server machine. Network install.
- Or 2, use setup
manager, setupmgr.exe, to create unattended installation batch file.
On installation disk or your copy on hard drive, find tools\deploy.cab.
Or it may be c:\support\tools\deploy.cab. Grab all subfiles form deploy.cab
and put in windows dir?
- Makes unattend.txt
answer-file or you may use another name. Run setupmgr.exe. Use
with cd, ris, etc. Ans questions in program screens here, once, instead
of multiple installation screens.
- Installation via
hard drive imaging uses sysprep plus third party imaging program
(norton Ghost). With Vista, 3rd party pgm is no longer needed.
Uses sysprep.exe and sysprep.inf is the answer file used with sysprep.
- Use norton’s Ghost
to…create a drive image. Or other drive image software. Later fix
ip address. Then fix CID (computer identifier). Thing to do is after
making image use MS utility called sysprep which takes image and strips
- For sysprep info
- also http://support.microsoft.com/kb/302577
- FAT16 largest partition
is 2G Fat 32 with win 95 release 2
- Terrabyte is 1000
- BIOS > POST (beep
error msg, text error msg) > CMOS > MBR > OSRECORD > NTLDR
(bootstrap loader). Once ntldr is found, BIOS terminates. See A-plus
book pg 312. For POST info see system startup troubleshooting.
POST, initialization (from CMOS?), boot (Osrecord, ntldr?)
Operating System Aspects
System Management BIOS, part of bios responsible for reporting configuration
data to diagnostics programs. Such as the DMI program that came with
your gigabyte mb?
- Driver signing defaults,
to make sure device drivers have been signed, or not, can be changed
at Computer > Properties > Hardware Tab > Driver signing
- Win 98 system.dat,
- In Windows XP, 2000,
and 2003 there are several Registry files. These files are named without
a file extension and are stored in the Windows\System32\Config folder.
These files are named Software, System, SAM, Security, Default, and
UserDiff. There is one more Registry file and it does have a file extension,
NTuser.dat. In Windows XP, 2000 and 2003, NTuser.dat is stored in the
users profile folder under the Documents and Settings folder. Each user
has their own NTuser.dat file. The NTuser.dat file stores all settings
that each user selects; these settings will override settings stored
in the System file.
- Each registry file
corresonds to a registry hive.
- BIOS cmos generally
has 2 kinds of passwords, supervisor and user. User allows user to get
into computer, at boot. Supervisor allows them to get into cmos.
- Allowing full control
to a user, for a folder, enables user to do whatever he wants to files
and folders within, no matter what his level of permissions for those
files and folder.
- Permissions are
assignable by the “owner” of a file. Whoever created the file. Groups
and users that are given permissions are called “security principals.”
They are put on an access control list in the form of an access control
- Smart cards. They
use EAP authentication (Extensible Authentication Protocol). An example
of an EAP auth protocol is EAP-TLS – EAP Transport Level Security.
CHAP does not support smart cards. PAP password authentication Protocol
uses plain text password to authenticate. CHAP is encrypted password
but not used with smart card.
- System Info is msinfo32.exe.
First tab is “system summary.”
- Memory devices,
flash drive uses usb, secure digital flash memory. SDF can use drive
bay device or “external card reader.”
- Start Menu. Sorting
it in Windows 2000 is different than XP. There is a button for it in
Taskbar Properties, instead of doing R-click > Sort. Get to taskbar
prop via Start > Settings > Taskbar prop, instead of
R-click taskbar > Prop.
- Backing up a file
as part of a full backup, or incremental backup, sets its archive-please
bit to 1, archive-please. It is normally called the archive bit
but I call it the archive-please bit. A file marked with this
bit is not a file that has been marked as being archived, it is a file
that has been marked as needing
to be archived.
- Full backup sets
the bit to zero, for every file backed up (sometimes described as “clears
the archive bit”). If files are subsequently changed, their archive-please
bit will be set to 1 again (“sets the archive bit”).
- Incremental backup
will see this and back them up, that is, incremental will back
up any files that have changed since full backup. It also sets their
archive-please bit to 0, thus indicating they are archived and do not
need to be archived again unless they are changed. At next incremental
backup a new incremental backup file will be made. There will be a full
backup file, an a number of incremental backup files.
- Differential backup
backs up changed files, however it does not set their archive-please
bit to zero. Therefore at next diff backup, files archived after the
original full backup, are still marked as archive-please, and will get
backed up again. Everything since full backup gets archived again. However
there will only be 2 backup files, the original full backup file, and
only one differential backup file.
- Copy avoids changing
- Virtual memory:
Unless you have at least 2 Mb of virtual memory, on boot volume, you
won’t be able to do any sort of memory dump. (2mb is very little.)
For pagefile efficiency, you can have most of your virtual mem on another
volume. Memory dump is useful debugging file.
- Three kinds of memory
dump: Complete, Kernel and Small memory dump (64
KB). See Overview
of Mem Dump File Options
shows all system RAM in event that computer stops unexpectedly.
This includes kernal memory, and all the processes that were running.
Requires paging file (virtual mem) that is, 1, on the boot volume and
2, sufficient to hold all the physical RAM plus 1 megabyte (MB). Complet
dump is not available if computer is 1, running a 32-bit operating system
and 2, has 2 gigabytes (GB) or more of RAM. Overwrites previous files;
- Kernel (the
mose useful?) mrecords only the kernal memory and HAL hardware abstraction
layer. Requires approx between 150MB and up to 2GB of pagefile size.
Overwrites previous files; won’t append
- Small memory
dump. Requires 2 mb on boot volume. This is the only kind that can
make a new file with each news stop. Special folder with history of
these files. Can be renamed but is generally %SystemRoot%\Minidump.
Sequence of files is made,
all with the extension *.dmp.
- You can load complete
memory dumps and kernel memory dumps with standard symbolic debuggers,
such as I386kd.exe. I386kd.exe is included with the Windows 2000
Support CD-ROM. Load small memory dumps by using Dumpchk.exe.
Dumpchk.exe is included with the Support Tools for Windows 2000 and
Windows XP. You can also use Dumpchk.exe to verify that a memory dump
file has been created correctly.
- MS recommends creating
page file on all disk volumes, but esp on volumes on other drives and
on drives on other controllers, than the boot partition. The virtual
memory algorithm will give preference to drives that are less frequently
used for data.
- Sigverif.exe can
be used to check system files (and others) for digital signature from
MS. Makes a log file sigverif.txt.
Users, Groups, User Profiles
- Users and Groups
Section 1, main user-group config:
Start > Run > Control userpasswords brings up same screen
as Control Panel > Users Accounts. Simple user and group gui.
- Users and Groups
Section 2, advanced user and group config:
Start --> run --> control userpasswords2 goes to screen where
you can create users with different permissions I don’t know
of any other way to get here than via Start > Run. Here, like in
Control Panel > User Accounts, you can add users, remove them, config
properties, and what groups they belong to. More users listed than at
Control Panel > User Accounts. From the advanced tab you can add
username-passwords combinations for users of other networks, including
web site users. Takes you to same place as My Computer > R-click
> Manage > Local Users and Groups > users.
- Users and Groups
Section 3, Local Users and Groups snap in: Once at Control userpasswords2,
also on the advanced tab, there is a button that will take you to good
old Local users and Groups.
You can also get to local users and groups from an mmc snapin. There
is one preconfig, under Start > Administrative Tools > Computer
Management. You can also get there from R-Click My Computer > Manage.
If computer is member of domain and joined to a domain, Local Users
and Groups snap in will be unavailable. These seem to do everything
that control userpasswords2 can do, and more, so I don’t see much
point in using control userpasswords2.
- Users and Groups
Section 4, User Profiles: From My Computer > Properties >
Advanced Tab > User profiles
section > Settings button, you can get to configure user
profiles for the users of the computer. This includes disk directories
where user profiles are stored, and there is a check box for roaming
profiles, which is relevant if user is a domain user and a roaming profile
has already been set up in active directory.
Sharing And permissions
- Share permissions
are the only way to secure network resources on FAT and FAT32 volumes, because NTFS permissions are not
available on FAT or FAT32 volumes.
- Share folders
and files applies to folders only (and all files under it). You
can not make a file a network share, only a folder.
- Share has
3 permissions, Full, Change, and Read.
- Standard share permission
when you make a folder shared is making it Read, for Everyone. However
everyone is not added to the NTFS security permissions. If you
add a new user, his/her Share permissions are set to allow
Read. His or her NTFS security permissions are set to everything
checked off. To give users more, you need to explicity give them permissions.
- No advanced permissions.
- There are 6 basic
NTFS security file permissions, and 7 folder permissions. The file permissins
are Full, Modify. Read and Execute, Read, Write, Special. Folder
permissions have an additional permission, List Folder Contents.
- Add a new folder
or add a new file, and its ntfs security permissions may or may not
be inherited from folder above it, depending upon inheritance choices
- 14 advanced permissions.
Remote Desktop and Remote Assistance
- The computer that
is being accessed is called the server, and the computer that accesses
it, the client. Sybex calls them remote and home respectively. The server
comptuter is also called the “terminal server.”
- The server must
have XP Pro on it. The client (home computer) needs only XP Home.
The server computer is running Remote Desktop. The client computer is
running Remote Connection.
- However your XP
Home computer (server) can be accessed with Remote Assistance
from another computer (client). If you are at this “server” ou can
ask for help with it, by sending an “invitation” to a client
to please help me. A client can also initiate an offer
of help. Ask for help, invite help, via MSN messenger or email msg.
Ask for help at Start > All programs > remote assistance invitation.
Or go to Help and Support > Invite a friend to do Remote Assist.
Offer help by Help and Support > search for Offer Remote Assist.
You may have to explicitly enable Local Comp Policy > Comp Config
> Admin Template > System > Remote Assist > Offer Remote
Assist > Enable. And click Show and put name (on server) in.
Don’t forget to do gpupdate. And possibly enable Solicit Remote Assist
on the server computer.
- But Remote Assistance
is a bit different than remote desktop. Configure remote assistance
in My Comp > Prop > Advanced > Remote tab. Remote Desktop is
config here too.
Windows Op Sys Troubleshooting
- Generally preference
order for fixing problems is safe mode, boot to last known good config,
ASR, Recovery console. ASR does the recovery console automatically.
- To install Win 2000
or Win XP recovery console: c:\i386\winnt32.exe
/cmdcons. Or you can run
Recovery Cons directly from Windows installation CD.
- ASR (automated system
recovery). For asr to work, you’ll have to have first made an ASR
backup, using the backup program). Backup makes a backup to a tape or
hard drive, plus makes a special floppy that you put in during boot.
- You’ll be given
choice to press F6 as CD boots. You cannot find this ASR F6 choice if
pressing F8 to load windows in safe mode. Similar thing re running recovery
console choice from cd.
- ASR will run from
CD. You may need to config cmos to boot from cd.
- You may need to
do a registry setting so that you can use recovery console wo a password.
I did. This setting is explained in my Compaq Win XP notes.
- ERD or emergency
repair disk was used in windows 2000 and earlier. It is a floppy. No
longer used. ASR used instead.s
- Virus, worm, Trojan.
- Virus relies on
other programs to function. It is not embedded in software like a trojan
is, however it relies on the other program to make it work. Trojan is
embedded in an application program. Worm is self-contained progam that
does not require support of other programs.
- SNMP, Simple Network
Management protocol. Runs as a service. You can configure it there.
But to see its output you need a program that is not installed on xp
automatically. It is however in windows support tools.
System startup troubleshooting, BIOS,
||Power supply bad, system not
plugged in, or power not turned on
||If everything seems to be
functioning correctly there may be a problem with the ‘beeper’ itself.
||Power supply may be bad
||p s p s p s|
||Power supply bad
||ppss ppss ppss|
long, two short beeps
||Video card failure
||wiideoo crd crd, wiideoo crd
POST Display codes
100 to 199 - System boards
200 to 299 – Memory (RAM)
300 to 399 - Keyboard
400 to 499 - Monochrome display
500 to 599 - Color/graphics
600 to 699 - Floppy-disk
drive or adapter
700 to 799 - Math coprocessor
900 to 999 - Parallel printer
1000 to 1099 - Alternate
1100 to 1299 - Asynchronous
communication device, adapter, or port
1300 to 1399 - Game port
1400 to 1499 - Color/graphics
1500 to 1599 - Synchronous
communication device, adapter, or port
1700 to 1799 - Hard drive
1800 to 1899 - Expansion
2000 to 2199 - Bisynchronous
- SMKMCF: sysboard,
mem, keyboard, mono, color, floppy. 100,200…600. 900 parallel port.
- Link light, activity
- OSI Model
7 layers PDNTSPA
- Physical, Datalink,
Network, Transport, Session, Presentation,
- Physical Layer
- Datalink layer.
Data frame. Size spec. Has info abt from addreess and to address (MAC
addresses, within same subnet) , info to physical, system for
deciding which packets go and which don’t go. Picks packets from those
sent from multiple devices. Decides which to send to phys layer. Card
- Network layer.
Provides network-wide addressing. Routing packets. Decides where to
send packet. IP protocol is an example. Network addresses used for multiple
networks. TCP/IP software.
- Transport layer.
End to end communication and reliable data delivery. Also called
Host to host layer. Has the TCP portion of TCP/IP. UDP. Segment
info into packets at the size spec by data link layer. Ethernet packet
size 1500 bytes incl crc. Also error detection and possibly error correction.
Isolates upper layers from details of transfer. Doesn’t know if below
are ether link or token ring or what. Most likely app presentation
and session are a single application. For example web browser. Protocols
– connection oriented or connection-less. Connection-Oriented: connection
established. Packet sent, acknowledged. If packet lost it’s resent.
Data goes back and forth in a tracked and sequenced manner. Data transfers.
TCP. SPX (netware). Connection-less: no connection made. If packet is
lost, it’s not resent. Broadcast or announcement packet. UDP, IPX.
Net Bios. Netware Core protocol Manage and track user sessions. Windows:
Workstation and Server Service Software. Netware: Redirector, requestor.
These days, the Windows client for Netware.
layer: common data formatting between communication devices. MIME
prototocol. Multipurpose Internet Mail. Makes sure receiving station
can receive data sent by transmitting station. MIME resides inside email
client. Eudora? Part of workstation and server service software if you
are connecting to shared files and printers.
- Application layer:
gives end user applications (such as MS Word?) access to network resources.
The actual applications do not include the application layer. Application
not in MS Word, but rather, in windows, in Workstation and Server Service
Software (Windows), Windows Client for Netware (Netware). “Network
client” protocol generally does functions of all of the top 3 layers,
application, presentation, and session.
- 90 percent of troubleshootng
is in bottom 4 layers. P, D, N, T.
- Types of LAN’s
- MAU in regard to
token ring topology is a Multistation Access Unit. MAU in regard to
10Base-5 thicknet ethernet is a Media Access Unit, or Ethernet transceiver,
which connects to the coax cable (in a physical bus topology) with a
vampire tap. The MAU connects to the NIC with DB-15 style connectors
called DIX or AUI connectors.
- Cable. 10BaseT requires
cat 3. 100BaseT, cat 5. 1000baseTX, cat 5e.
- All 3 work up to
100 meters. 328 feet.
- Fiber optic connectors.
- More fiber optic connectors. See http://www.thefoa.org/tech/connID.htm
- All used with either
multimode or single mode fiber cable
- ARP: address resolution
protocol. Used to associate MAC address with IP address.
allows you to configure network paramaters, much like the Network connections
window does. Netsh is used from the command line.
- Wireless Application
Protocol, different than Wireless Access Point, is a protocol used by
wireless devices, generally mobile ones such as phones. Both abbreviated
WAP. Wireless Application protocol is a protocol for wireless devices
like phones, like http is a protocol for computers. WTLS is to Wireless
Application Protocol as TLS is to http-https-html. (Hypertext transfer
protocol, markup lang).
- static routing:
network admin writes in routing tables.
- Dynamic routing:
“route discovery protocols,” routing protocols, get info from other
- Two categ of dynamic
routing, distance vector and link state.
- Distance vector
routing includes RIP (routing Information Protocol) for TCP/IP and RIP
- Link state
is faster and more efficient. Multicast or unicast rather than broadcast.
As a last resort Open Shortest Path First (OSPF) is used; performs a
database synchronization (every 30 min).
- Two Link State Routing
protocols that are of the link state
kind (a kind of dynamic routing protocol) are: Netware Link Services
Protocol (NLSP, for IPX) and Open Shortest Path First for TCP/IP
- Networking Protocls:
routable and non-routable see table 2.4 on pg 74 of Net Plus book (NetBEUI
- AT (ATtention) commands.
Developed by Hayes, used universally. AT followed by A-Z or &A -
&Z. ATDT nnnnnnn, Dial Tone. Then the number. ATA, answer mode,
off-hook. ATH0: switch-Hook mode, hang up mode. Allows for using AT
commands. ATH1: off-Hook, auxilliary relay. AT&F, set to factory
defaults, including S-registers. ATZ resets defaults but not S-registers.
ATSn=x: changes s-register n, to x. Sn?: read s-reg n. ATI: identify
modem. AT&x: additional set of commands using A-Z.
- S registers. S0:
number of rings to answer on. S8: pause time for dial-comma. Result
codes: 0, OK, command executed; 1, CONNECT, connection has been established;
2: RING, ring detected. 158: CONNECT 33600/ARQ/V34
Wire Troublehooting Tools
- Time Domain Reflectometer.
Only need one end of wire to test for quality of continuity. Shorter
wire will take less time to reflect signal. Estimate how far away the
- Private key, same
key encrypts and decrypts. Also known as symetrical.
- DES is Data Encryption
Standard A private key encryption sys.
- WEP, a private key
sys, is Wireless Equivalent Privacy, deprecated security system.
- Two methods of
authentication can be used with WEP: Open System authentication
and Shared Key authentication. Due to some esoteric technical flaws
it’s entirely possible for an eavesdropper to intercept enough WEP-encrypted
packets to eventually deduce what the key is. WPA (WiFi Protected Access)
certification program to indicate compliance with security protocols.
It addressed WEP’s shortcomings. Temporal Key Integrity Protocol (TKIP),
was added to WPA. For encryption. TKIP is a required part of
WPA. There is also AES encryption. It is stronger than TKIP. And optional.
The easiest-to-use and most widely supported version is WPA Personal,
sometimes referred to as WPA Pre-Shared Key (PSK). To encrypt a network
with WPA Personal/PSK you provide your router not with an encryption
key, but rather with a plain-English passphrase between 8 and 63 characters
long. Using TKIP, that passphrase, along with the network SSID, is used
to generate unique encryption keys for each wireless client. And those
encryption keys are constantly changed. (Although WEP also supports
passphrases, it does so only as a way to more easily create static keys,
which are usually comprised of the hex characters 0-9 and A-F).
- Note that although
WPA is an encryption method, in Windows prop sheet for the wireless
adapater in your computer, you will find it listed in the authentication
drop down box, as opposed to in the encryption drop-down box, where
it should belong. Afer selecting it, you’ll be given a choice of tkip
- In the linksys program,
wep and wpa will be listed in a drop down box labeled “security.”
Linksys also has Radius and LEAP. Choice of tkip or aes will be listed
on next page (after you press Next). Also, if you chose wpa, (wep?)
will you be given choice of authentication method (added security, in
addition to encryption), shared key (this is a pre-shared key)
or open system. WPA-person (wps-psk) has no such choice, but
wpa-enterprise has many choices, including tkip vs aes. LEAP and RADIUS
also have many choices. In the win program, you will have several varities
of wpa to choose from (but no LEAP or RADIUS choice), all with tkip
and aes choices.
- Router has choice
only of WEP or WPA-PSK (WiFi Protected Access Pre-Shared-Key).
- The “windows security”
dialog box is the box that shows first when you press ctrl-alt del,
and you are in user log-off mode (single user mode). Here you have a
choice of lock, log off, shut down, task manager, etc. In multiple user
mode, Windows Task Manager comes up right away.
- Only a cpu and monitor
should be connected to a 500 va watt ups.
- You can send someone
to a phony website more easily if they are using a hyperlink to get
to the site, instead of putting the address into the address bar. Users
usually don’t look at the actual address, in the status bar or wherever.
The actual link can be to a page that is different than the name of
the link. This is called “hyperlink spoofing.”
- Malware. Worm gets
tranmitted over network, replicating on one comupter after another.
- Boot virus is malware
that infects boot sector on hard disk. Prevents hard disk from booting.
- Email virus: spread
- Trojan: not spread
thru network insecurity, but rather by people trading infected programs,
that otherwise may be working programs. You need to execute the program,
for the trojan to be installed. Will damage programs or data on the