Wednesday, January 31, 2018
Tuesday, January 30, 2018
Which of the following is not a requirement of an elastic system?
Which of the following is not a requirement of an elastic system?
- CPU, GPU, RAM, storage availability
- Provision/deprovision resources
- Monitor resource usage
- Leprechauns
EXPLANATION
According to a paper from Karlsruhe Institute of Technology, "Elasticity is the degree to which a system is able to adapt to workload changes by provisioning and deprovisioning resources in an autonomic manner, such that at each point in time the available resources match the current demand as closely as possible." https://sdqweb.ipd.kit.edu/publications/pdfs/HeKoRe2013-ICAC-Elasticity.pdfResources such as CPU cycles, RAM, and storage are all necessary to provision to a client account. What makes elasticity different from simply being scale-able is that systems can be automated to add or remove these resources pending the outcome of a monitoring routine. Generally speaking, an elastic system doesn't require a Leprechauns to operate.
SOURCE
https://sdqweb.ipd.kit.edu/publications/pdfs/HeKoRe2013-ICAC-Elasticity.pdfWhich type of RAID configuration requires minimum six drives?
Which type of RAID configuration requires minimum six drives?
- RAID 60 (RAID 6 + 0)
- RAID 50 (RAID 5 + 0)
- RAID 100 (RAID 10+0)
- RAID 6
EXPLANATION
RAID 50, also called RAID 5+0, combines the straight block-level striping of RAID 0 with the distributed parity of RAID 5.[3] As a RAID 0 array striped across RAID 5 elements, minimal RAID 50 configuration requires six drives.SOURCE
https://en.wikipedia.org/wiki/Nested_RAID_levelsFriday, January 26, 2018
When it comes to associative memory, how does the memory locate the address of the data?
When it comes to associative memory, how does the memory locate the address of the data?
- The address of the data is supplied by the users
- The address of the data is generated by the CPU
- The data are accessed sequentially
- There is no need for an address, the data is used as an address
EXPLANATION
Associative memory is memory capable of determining whether a given datum (the search word) is contained in one of its addresses or locations. Associative memory is also referred to as content-addressable memory.Unlike standard computer memory (random access memory or RAM) in which the user supplies a memory address and the RAM returns the data word stored at that address, associative memory is designed such that the user supplies a data word and the computer searches its entire memory to see if that data word is stored anywhere in it.
Thursday, January 25, 2018
What is the non-linear function that made DES cryptography so strong?
What is the non-linear function that made DES cryptography so strong?
- Trick question, DES is fully linear
- Swapping 4 bytes (left and right) after every round
- Expansion & Contraction algorithms
- 16 rounds of S-Box lookups
EXPLANATION
The genius of Horst Feisel's cipher was in the use S-Boxes for a non-linear lookup function based on the bit values of the ciphertext within each round. Operating on only 1/2 the ciphertext per round, the 48 expanded bits are chopped into 6-bit inputs across the 8 S-Boxes, with each 6-bit input performing a row/table lookup to yield 4 bits of output. Without this non-linear function, DES would have been linear, and thus very weak.This design is even more impressive when you consider that the process ran the same forwards and backwards for encrypt/decrypt, and was optimized for hardware. While met with great suspicion when introduced, the Data Encryption Standard proved worthy of the trust provided it, weathering every attack except Moore's Law and time, which ultimately led to its obsolescence due to brute force attacks. 40 years later, the field of cryptography, and the fabric of the Internet and digital commerce, owes much to the knowledge we gained regarding cryptanalysis and ciphers from this legacy
SOURCE
https://en.wikipedia.org/wiki/Data_Encryption_Standard#The_Feistel_.28F.29_functionWednesday, January 24, 2018
Tuesday, January 23, 2018
What version of Office are you using when the installation folder is Office14?
What version of Office are you using when the installation folder is Office14?
- Office 2014
- Office 2010
- Office 2013
- Office 2016
EXPLANATION
Microsoft started office at version one and put the version number at the end of the folder. Beginning with Office 95, Microsoft started naming the versions after the years in which they were released, but they kept using the version number for the program folder.SOURCE
http://www.ryadel.com/en/microsoft-office-default-installation-folders-versions/What is the default port used by a POP3 server for communicating with a POP3 client?
What is the default port used by a POP3 server for communicating with a POP3 client?
- 587
- 110
- 109
- 25
EXPLANATION
Port 110 is the default POP3 non-encrypted port.Port 995 is the default POP3 port for encrypted (SSL) traffic.
SOURCE
http://quiz.techlanda.com/2017/12/what-is-default-port-used-by-pop3.htmlFriday, January 19, 2018
When installing a new domain controller into an exisiting Windows Server 2012 R2 domain using Windows PowerShell, which cmdlet do you use?
When installing a new domain controller into an exisiting Windows Server 2012 R2 domain using Windows PowerShell, which cmdlet do you use?
- Promote-ADSDomainController
- Install-ADDomainController
- Get-ADDSDomainController
- Install-ADDSDomainController
EXPLANATION
When installing a new domain controller into an existing AD domain, use the Install-ADDSDomainController cmdlet and the parameters that meet your needs.SOURCE
https://technet.microsoft.com/en-us/library/hh974723%28v=wps.630%29.aspxThursday, January 18, 2018
What are VM snapshots intended to be used for?
What are VM snapshots intended to be used for?
- To easily revert the VM to an earlier state
- To shut down the server
- As a backup tool for your VMs
- To create albums
EXPLANATION
Snapshots provide a fast and easy way to revert the virtual machine to a previous state. For this reason, virtual machine snapshots are intended mainly for use in development and test environments. Having an easy way to revert a virtual machine can be very useful if you need to recreate a specific state or condition so that you can troubleshoot a problem.There are certain circumstances in which it may make sense to use snapshots in a production environment. For example, you can use snapshots to provide a way to revert a potentially risky operation in a production environment, such as applying an update to the software running in the virtual machine.
Many backup products use snapshots in a production environment. They create a snapshot and then processing continues from the snapshot, meanwhile they have an unchanging original to back up. Once the backup is completed the snapshot is merged back into the live environment. This allows a machine to be backed up with very little affect for the users and for them remains up 24/7.
NB: Hyper-V snapshots do not replace backups. Backup usually involves some form of duplication (so two copies of the protected data exist) but in snapshots... there is no duplication whatsoever. All data is in VHD(X) file and changes in AVHD(X) file and if the VHD(X) file is damaged/lost, the data is pretty much gone. Also with most backups you can restore a single file to an earlier state, but with Snapshots, it's all or nothing (meaning if an user wants a file from last week, you'd have to bring the whole system back a week). There are other concerns as well (there might be performance issues with multiple snapshots, snapshots usually lose value as they age and there are issues with disk space)
SOURCE
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1015180Wednesday, January 17, 2018
The 'CAT' (Category) rating on a multimeter relates to its capability to
The 'CAT' (Category) rating on a multimeter relates to its capability to:
- Survive in tough environments
- Reduce user hazards
- Maintain high accuracy
- Provide extended battery life
EXPLANATION
The Category rating, typically CAT I, II, III, IV etc, relates to the ability of the meter to avoid creating a safety hazard when subjected to a massive overload, as for example when inadvertently connected directly across a supply when on a current range. It does not necessarily imply that the meter will survive the abuse. Rather, that the result should not include user injury due to fire, insulation failure, arcing or bursting open of the case.Budget meters sold for use on small electronic projects do not typically have the protection devices (Especially, high breaking-current fuses) fitted to meters intended for measurements on distribution boards, etc. Therefore anyone intending such work should choose a meter with a suitable CAT rating.
http://support.fluke.com/find-sales/download/asset/1263690_6116_eng_h_w.pdf
SOURCE
http://support.fluke.com/find-sales/download/asset/1263690_6116_eng_h_w.pdfTuesday, January 16, 2018
What is the limiting factor that prevents older PCs from using a hard drive larger than 2.2 terabytes?
What is the limiting factor that prevents older PCs from using a hard drive larger than 2.2 terabytes?
- GPT (GUID Partition Table)
- MBR (Master Boot Record)
- RAM (Random Access Memory)
- UEFI (Unified EFI)
EXPLANATION
This limit arises from the maximum size of the master boot record (MBR) partitioning method used by most personal computers. BIOS systems with MBR disks use 32-bit values to describe the starting offset and length of a partition. Due to this size limit, MBR allows a maximum disk size of approximately 2.2 TB and a maximum of four primary partitions.UEFI supports the GUID Partition Table (GPT), a more flexible partitioning scheme. GPT disks use 64-bit values to describe partitions, allowing larger partitions. GPT also fixes other issues related to MBR (data integrity, backup tables, maximum number of partitions, ...). Using 64-bit values, GPT can handle disks of up to 9.4 x 10^21 bytes or 9.4 zettabytes (ZB).
SOURCE
http://www.uefi.org/sites/default/files/resources/UEFI_Drive_Partition_Limits_Fact_Sheet.pdfFriday, January 12, 2018
Which of the following protocols is not directly related to VOIP?
Which of the following protocols is not directly related to VOIP?
- Real-time Transport Protocol (RTP)
- Session Initiation Protocol (SIP)
- File Transfer Protocol (FTP)
- Inter-Asterisk eXchange (IAX)
EXPLANATION
Voice over Internet Protocol (also voice over IP, VoIP or IP telephony) is a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet.
Voice over IP has been implemented in various ways using both proprietary protocols and protocols based on open standards. VoIP protocols include:
Session Initiation Protocol (SIP) H.323Media
Gateway Control Protocol (MGCP) Gateway Control Protocol (Megaco, H.248)
Real-time Transport Protocol (RTP) Real-time Transport Control Protocol
(RTCP) Secure Real-time Transport Protocol (SRTP) Session Description
Protocol (SDP) Inter-Asterisk eXchange (IAX) Jingle XMPP VoIP extensions
Skype protocol
SOURCE
https://en.wikipedia.org/wiki/Voice_over_IPWhat is Puppet used for?
What is Puppet used for?
- Advanced threat management
- Configuration management
- Remote desktop operations
- Backups and restores
EXPLANATION
Puppet is an open-source configuration management tool that runs on Unix-like systems as well as on Microsoft Windows. It has its own declarative language that you can use to describe your system's configuration.When a user computer or device (like a cell phone, tablet, or printer) is having general, odd software problems, what is the most common easy fix?
When a user computer or device (like a cell phone, tablet, or printer) is having general, odd software problems, what is the most common easy fix?
- Turn it off and on again
- Update the drivers
- Attach a debugger to the port
- Replace the flash memory
EXPLANATION
Computerized devices have become extremely complex in software and hardware interactions.The highly interwoven tangle of software dependencies will frequently cause small memory leaks, resource contentions, and other unexpected results, cascading over time. Just like a deep cleaning in the kitchen is great for a chef to maintain food quality, a reboot is oftentimes the quickest and easiest way to get a misbehaving system to clear its slate and get back into an operating state.
Sadly, since the concept is so simple and seems inane, many users will not do it when instructed. Performing this quick and basic step first thing will often correct the original issue and if it doesn't (and the user complains they did it already), it still provides the benefit of starting troubleshooting with the knowledge that you're starting from a basic system state.
Friday, January 5, 2018
Who is credited with developing the Virtual Integrated Network Service?
Who is credited with developing the Virtual Integrated Network Service?
- ePresence
- Unisys
- IBM
- Banyan Systems
EXPLANATION
In 1984, Banyan Systems introduced a set of network protocols and a computer network operating system known as Banyan VINES (Virtual Integrated Network Service). It was most commonly used by government entities, but later became obsolete as newer technologies from Microsoft and IBM began to overshadow its existing systems.Thursday, January 4, 2018
Wednesday, January 3, 2018
Which of the Following is NOT a Sync Type when Syncing Files and Folders using SyncToy, FreeFileSync and other File Syncing Tools?
Which of the Following is NOT a Sync Type when Syncing Files and Folders using SyncToy, FreeFileSync and other File Syncing Tools?
- Mirror
- Dedupe
- Sync (Two-Way Sync)
- Contribute (Update)
EXPLANATION
Dedupe is a Storage Technology which operates on a block level to save storage space using pointers to data blocks. It is not a file level operation.Contribute / Update -> Updates Files from the Left Folder Path to the Right without deleting any files or folders. Renamed, Modified and New Files and Folders are added from Left to Right.
Sync (Two-Way Sync) - New items, Renames, Modifications and Deletions are synced from Left to Right and Right to Left Paths (both directions).
Mirror - Copies and Overwrites all file and folder items from the Left Path to The Right Path - creates a mirror copy from Left to Right File Paths. Useful for Backups to removable storage such as USB External Hard Drives.
SOURCE
https://en.wikipedia.org/wiki/File_synchronizationWhat do registers provide for the CPU?
What do registers provide for the CPU?
- Enable the CPU to control the address bus
- Determine the clock speed
- Enable the CPU to address RAM
- Provide temporary storage of internal commands
EXPLANATION
A processor register is a quickly accessible location available to a digital processor's central processing unit (CPU). Registers usually consist of a small amount of fast storage, which the CPU uses to temporarily store internal commands and data.Which codec requires a license to use?
Which codec requires a license to use?
- H.323
- G.722
- G.711
- G.729
EXPLANATION
G.729 is a paid and licensed codecSOURCE
https://nexbridge.co.uk/what-is-the-difference-between-g711-g729-and-gsm-and-why-does-the-codec-matter/Which of the following is not an automatic variable in PowerShell?
Which of the following is not an automatic variable in PowerShell?
- $Matches
- $Last
- $args
- $Error
EXPLANATION
While there are automatic variables for the last cmdlet executed, the last argument used in that cmdlet, and the exit status (False if it threw an error; True if it didn't), there is no automatic variable that represents the last full command, or the last command's output. $Last is not an automatic variable in the shell.$Error is an array that's populated by all errors output in the current session (by default, up to 256 errors, although this can be changed by changing the value in $MaximumErrorCount).
$args is an array containing any command line arguments that were passed to a function or script; it's only usable from within that function or script. Typically, this is not used as "param()" is a lot more powerful and typically easier to work with.
$Matches is an array containing the results of the last match with regular expressions against a string. Note that it does not get populated if the match was performed against an array; in that case, -match just outputs the matching items directly to output.
According to ITIL, which of the following should IT services provide to customers?
According to ITIL, which of the following should IT services provide to customers?
- Skills
- Risk
- Value
- Costs
EXPLANATION
From the customer's point of view the value of a service consists of two basic elements:Utility: The functionality offered by a product or service to meet a particular need. Utility can be summarized as ‘what the service does’, and can be used to determine whether a service is able to meet its required outcomes, or is ‘fit for purpose’. The business value of an IT service is created by the combination of utility and warranty.
Warrancy: Assurance that a product or service will meet agreed requirements. This may be a formal agreement such as a service level agreement or contract, or it may be a marketing message or brand image. Warranty refers to the ability of a service to be available when needed, to provide the required capacity, and to provide the required reliability in terms of continuity and security. Warranty can be summarized as ‘how the service is delivered’, and can be used to determine whether a service is ‘fit for use’. The business value of an IT service is created by the combination of utility and warranty.