CISSP Access Control Models

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Data access controls are established to control how subjects can access data, what they can access with it, and what they can do with it once accessed. Three primary types of access control are discussed in this section.

 

[bs_icon name=”glyphicon glyphicon-chevron-right”]   Mandatory Access Control (MAC)

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CISSP Kerberos

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Kerberos is a network authentication protocol created by the Massachusetts Institute of Technology (MIT) that uses secret-key cryptography. Kerberos has three parts: a client, server, and trusted third party (KDC) to mediate between them.

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CISSP Attacks

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[bs_icon name=”glyphicon glyphicon-chevron-right”] Types of Attacks

  • Denial of Service (DoS)
  • Smurf
  • Fraggle
  • SYN Flood
  • Teardrop
  • Distributed Denial of Service (DDoS)
  • Ping Sweep
  • Port Scan
  • Salami attack
  • Man-in-the-Middle
  • Session or TCP Hijacking
  • Replay
  • Buffer Overflow
  • Scareware and Ransomeware
  • Password attack
  • Covert channels

[bs_icon name=”glyphicon glyphicon-chevron-right”]  Web Attacks

  • SQL Injection – An injection of SQL query through input data from client to application (database).
  • Command Injection – User injects commands specified by an attacker in a vulnerable application – usually due to lack of strict input validation requirements in application.
  • Cross Site Scripting – Where malicious scripts are injected into an otherwise benign and trusted website and action traverses to another website.
  • Cross Site Request Forgery – In which a user is made to execute unwanted actions in a web application by an attacker.
  • Zero Day Exploits – attacks that take advantage of vulnerabilities that are unpublished and unknown by the vendor.

Source by wikipedia

 

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CompTIA A+ | Microsoft MTA O/S: Malicious Software (Malware)

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Definition – What does Malicious Software (Malware) mean?
Malicious software, commonly known as malware, is any software that brings harm to a computer system. Malware can be in the form of worms, viruses, trojans, spyware, adware and rootkits, etc., which steal protected data, delete documents or add software not approved by a user.

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CompTIA A+ | Microsoft MTA O/S: ATX

Posted by & filed under CompTIA A+, MICROSOFT MTA O/S.

ATX 12V 2.x Power Supplies connect to the motherboard by way of 24-pin cable + 4-pin for CPU and 6 or 8-pin for video.
 
 

Advantages of the ATX motherboard

  1. The ATX motherboard includes advanced control facilities, where the BIOS program continually checks the CPU temperature and voltages, the cooling fans RPM, etc. If overheating occurs, the PC will shut down automatically.
  2. The ATX motherboard has a stacked I/O connector panel mounted on the motherboard.
  3. On a socket 7 ATX motherboard, the socket has been placed a further distance from the expansion slots, allowing for long boards to be placed in easier.
  4. ATX 2.01 includes a single keyed, Molex internal power supply connector which cannot be placed improperly. However, its standby voltage needs to be greater than 720 mA. While the Molex power connector allows for 5v and 3.3v to be connected, it is recommended that only a 3.3v be used.
  5. Relocation of the memory and the CPU allows for better ventilation and easier installation.
  6. Power management is now possible with proper BIOS support.
  7. The PC can also be turned on by a modem or network signal, since the power supply is controlled by the main board.
  8. The computer cannot be turned off as the computer boots. However, if the computer freezes as it is turning on you can turn off the computer by holding the power button for five seconds.

 

 

**Source by wikipedia **

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CompTIA A+ | Microsoft MTA O/S: RAID

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RAID stands for Redundant Array of Inexpensive Disks.

  • RAID 0  is striping,
  • RAID 1  is mirroring ,
  • RAID 5  is striping with parity,
  • RAID 10  is mirrored sets in a striped set.

[bs_icon name=”glyphicon glyphicon-arrow-right”] RAID 0  is not fault-tolerant. If RAID 1 uses two disk controllers, it is disk duplexing.

 

raid 0

raid_1

 

raid_5

 

raid1 0

 

 

 

Short for Redundant Array of Inexpensive Disks, RAID is an assortment of hard drives connected and setup in ways to help protect or speed up the performance of a computer’s disk storage. RAID is commonly used on servers and high performance computers.

Spanning and Software Striping

Splitting information and writing it across multiple physical disk drives. RAID 0 utilizes this technique.

 

Mirroring

Duplication of data from one disk drive to another.

 

Duplexing

Duplicates the disk drive as well as the disk controller.

 

Deferred

Data is cached in cache memory and writes to the hard drive as the disk drive becomes available.

 

Hot Swapping

Failed disk drives can be replaced and data can be placed back onto the disk drive while the remainder of the system is in operation.

 

Hot Sparing

Disk drive is automatically initialized into the array when another fails.

 

Spindle Synchronization

Synchronization of the rotation of all disk drives in the array allowing information to be written all at once.

 

Versions of RAID

RAID 0

Software stripping and Block Interleave (minimum 2 drives). Data is written to each drive in succession, each block going to the next available drive (striping) for a faster operation and less chance of overloaded. The volume can of course be much larger than any single drive. Since no redundancy is provided, the failure of a single drive will bring the system down. RAID 0 is the fastest and most efficient array type, but offers no fault-tolerance.

 

RAID 1

Disk Mirroring and Duplexing ( minimum 2 drives ). Drives are used in pairs and all data is written identically to both drives. Each drive can be duplexed by being connected to its own interface controller. The failure of one drive will not bring down the system, instead the other drive will continue to operate. Of course, two drives are now used for the equivalent storage capacity of one drive. There is no performance gain with this level. The array of choice for performance-critical, fault-tolerant environments. Also, RAID 1 is the only choice for fault-tolerance if no more than two drives are desired.

 

RAID 2

Data striping and bit interleave. Data is written across each drive in succession, one bit at a time. Checksum data is recorded in a separate drive. RAID 2 is very slow for disk writes and seldom used today since ECC is embedded in almost all modern disk drives.

 

RAID 3

Data striping with bit interleave and parity checking. RAID 3 is similar to lever 2, but more reliable. Data striping is done across the drives, one byte at a time. Usually 4 or 5 drives are used providing very high data transfer rates. One drive is dedicated to storing parity information. The failure of a single drive can be compensated by using the parity drive to reconstruct the failed drive contents. Since the parity drive is accessed on every write operation, the writing of data tends to be slower. The failure of two drives or more can be a problem. RAID 3 can be used in data intensive environments with long sequential records to speed up data transfer. However, it does not allow multiple I/O operations to be overlapped and requires synchronized-spindle drives to avoid performance degradation with short records.

 

RAID 4

Block interleave data striping with parity checking. As in level 3, RAID 4 uses a single parity drive and block data striping like in RAID 0. The drives in this RAID level function individually, with an individual drive reading a block of data. A failure of the controller will of course be catastrophic. Offers no advantages over RAID-5 and does not support multiple simultaneous write operations.

 

RAID 5

Block interleave, data striping with distributed check-data on all drives. The one to use for NetWare. Parity information is distributed across all drives. RAID 5 efficiency goes up as the number of disks increases. You can use hot spares to rebuild a failed drive on “the fly”. The best choice in multi-user environments, which are not write performance sensitive. However, at least three, and more typically five drives, are required for RAID-5 arrays.

RAID 6

Extension to RAID 5, which adds a log structured file system providing a mapping between a disk drives physical sectors and their logical representation. As information is written it is placed to sequential physical disk sectors.

 

RAID 10

Stripped array whose segments are RAID 1 arrays and containing the same fault tolerance as RAID 1. High I/O rates are achieved by stripping RAID 1 segments. Excellent solution for those considering RAID 1 since it provides an good write performance, but is an expensive solution.

 

RAID 53

Implemented as striped RAID 0 array whose segments are RAID 3 arrays. RAID 53 also contains the same Fault tolerance and overhead as RAID 3. Excellent solution for those considering RAID 3 since it provides additional write performance, but is an expensive solution and requires all drives to have the same synchronization.

 

[bs_icon name=”glyphicon glyphicon-exclamation-sign”]Note: RAID can be setup with multiple partitions instead of multiple drives for some protection if sectors of the drive become bad. However, if the drive fails you will lose all of your data. For any RAID setup it’s best to use at least two drives to eliminate a single point of failure and total data loss.

 

What is RAID 0/1?

Some computer and RAID manufacturers have created their own scheme of labeling their RAID devices. For example, RAID 0/1 would mean that it combines the striping of RAID 0 with the mirroring of RAID 1.

 

Combo CompTIA Online

 

Source By:<www.computerhope.com>

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sound-card

CompTIA A+ | Microsoft MTA O/S: Sound cards

Posted by & filed under CompTIA A+, MICROSOFT MTA O/S.

Sound cards connect as x1 PCIe or PCI cards and normally have PC 99 color-coded 1/8” mini-jacks for I/O and speakers, and optical I/Os known as S/PDIF (example: TOSLINK).

 

Alternatively referred to as an audio output device, sound board, or audio card. A sound card is an expansion card or IC for producing sound on a computer that can be heard through speakers or headphones. Although the computer does not need a sound device to function, they are included on every machine in one form or another, either in an expansion slot (sound card) or on the motherboard (onboard).

 

 

Sound card connections

Back of computer sound cardThe picture is an example of a sound card audio ports oraudio jacks on the back of your computer, associated colors, and the connector symbols.

  • Digital Out (White or Yellow; words: “Digital” or “Digital Out”) – Used with surround sound or loudspeakers.
  • Sound in or line in (Blue; Arrow pointing into waves) – Connection for external audio sources, e.g. tape recorder, record player, or CD player.
  • Microphone or Mic (Pink; Microphone) – The connection for a microphone or headphones.
  • Sound out or line out (Green; Arrow pointing out of waves) – The primary sound connection for your speakers or headphones. This sound card also has a second (black) and third (orange) sound out connector.
  • Firewire (Not pictured) – Used with some high-quality sound cards for digital video cameras and other devices.
  • MIDI or joystick (15 pin yellow connector) – Used with earlier sound cards to connect MIDI keyboard or joystick.

Tip: Usually the cables connecting to the devices are also color-coded and will match or be close to the colors the cables connect into. For example, the end of the speakers cable may have a green line or be completely green.

 

 

Uses of a computer sound card

  • Games
  • Audio CDs and listening to music
  • Watch movies
  • Audio conferencing
  • Creating and playing Midi
  • Educational software
  • Business presentations
  • Record dictations
  • Voice recognition

 

 

 

Source By:<www.computerhope.com>

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