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Tuesday, July 14, 2020

As a general rule, when working with Access Control Lists (ACLs), the last line of the file should...

As a general rule, when working with Access Control Lists (ACLs), the last line of the file should...

  • Contain a full stop[Explicitly deny].
  • Implicitly allow all.
  • Be an implicit deny.
  • Only allow you. 

EXPLANATION

Explicitly deny all traffic with an EtherType ACE, then IP and ARP traffic is denied; only physical protocol traffic, such as auto-negotiation, is still allowed.
The file can contain blank lines.
As the last rule a general ban is inserted automatically.
To make it obvious, an explicit deny should be entered anyway as the last rule. The rules are checked sequentially from the “top down”. The first relevant rule determines the result (“first match”).

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In Windows, what does does WMI stand for?

In Windows, what does does WMI stand for?

  • Windows Management Instrumentation
  • Windows Machine Interface
  • Windows Management Infrastructure
  • Windows Management Interface 

In Windows, what does does WMI stand for?

EXPLANATION


Windows Management Instrumentation consists of a set of extensions to the Windows Driver Model that provides an operating system interface through which instrumented components provide information and notification.
WMI is Microsoft's implementation of the Web-Based Enterprise Management (WBEM) and Common Information Model (CIM) standards from the Distributed Management Task Force (DMTF).


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What does IaaS stand for?

What does IaaS stand for?

  • Infrastructure as a Service
  • Infrastructure as a System
  • Infrastructure as a Storage
  • Infrastructure as a Server

What does IaaS stand for?

EXPLANATION

IaaS Definition

IaaS offers businesses and organisations various services and solutions such as pay-as-you-go Cloud storage, networking and VM’s (Virtual Machines).

It offers a cloud-based alternative to on-premise infrastructure so that business don’t have to invest in expensive and on-site equipment.

To put that into simpler language; picture your I.T department for a moment. Do they have a server room somewhere in the building?

That’s on-premise infrastructure.

Now imagine that room wasn’t there anymore and those ‘servers’ were virtual machines on the internet. That’s IaaS.

Infrastructure as a Service delivered over the internet.
Benefits Of IaaS

Having on site infrastructure (like servers) is expensive, labour intensive, takes up valuable office space and with depreciation of hardware isn’t a great long-term investment.

It can often involve an expensive up-front cost for the physical hardware plus the cost of installing and then, on a day to day basis, maintaining it.

The benefit of IaaS is that you only need to buy what you need as you need it, purchasing more as your business expands.

This makes it a flexible and scalable solution that can be upgraded or replaced as per business demands compared to expensive physical hardware, that due to its high initial cost you may need to ‘get the most out of’, even if it’s long past it’s best.
Examples of IaaS

    Microsoft Azure,
    Amazon Web Services (AWS),
    DigitalOcean,
    Linode,
    Rackspace,
    Cisco Metapod,
    Google Compute Engine (GCE)

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In computing, what is a "bus"?

In computing, what is a "bus"?

  • Boolean Undulated Synchronization.
  • The part of the memory that processes data
  • A communication system that transfers data between components inside a computer or between computers
  • Binary Unified System

In computing, what is a "bus"?

EXPLANATION


Bus :-bidirectional universal switch
use to transfer data or power between computer components inside a computer or between computer.
point to point connection.

The bus contains multiple wires (signal lines) with addressing information describing the memory location of where the data is being sent or retrieved. Each wire in the bus carries a bit(s) of information, which means the more wires a bus has, the more information it can address. For example, a computer with a 32-bit address bus can address 4 GB of memory, and a computer with a 36-bit bus can address 64 GB of memory.

Types of computer buses

A bus is either a parallel or serial bus, and either an internal bus (local bus) or an external bus (expansion bus).
Internal bus vs. external bus

An internal bus enables the communication between internal components, such as a video card and memory. An external bus is capable of communicating with external components, such as a USB or SCSI device.
Parallel bus vs. serial bus


A computer bus can transmit its data using either a parallel or serial method of communication. With a parallel bus, data is transmitted several bits at a time. However, with a serial bus, the data is transferred one bit at a time.
Bus speeds

A computer or device's bus speed is measured in MHz, e.g., an FSB may operate at a frequency of 100 MHz. The throughput of a bus is measured in bits per second or megabytes per second.
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What is the maximum length specification for unshielded Cat6 cable when used in a 10GBASE-T environment?

What is the maximum length specification for unshielded Cat6 cable when used in a 10GBASE-T environment?

  • 328 ft (100m)
  • 100 ft (30M)
  • 180 ft (55m)
  • 365 ft (112m)

What is the maximum length specification for unshielded Cat6 cable when used in a 10GBASE-T environment?

EXPLANATION

Category 6 cable (Cat 6), is a standardized twisted pair cable for Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards.

Cat 6 has to meet more stringent specifications for crosstalk and system noise than Cat 5 and Cat 5e. The cable standard specifies performance of up to 250 MHz, compared to 100 MHz for Cat 5 and Cat 5e.

Whereas Category 6 cable has a reduced maximum length of 55 meters when used for 10GBASE-T, Category 6A cable is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same 100 meter maximum distance as previous Ethernet variants.
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From the old days of DOS, what does the "EMM" in EMM386 stand for?

From the old days of DOS, what does the "EMM" in EMM386 stand for?

  • Expanded Memory Manager
  • Enhanced Memory Module
  • Extended Memory Module
  • Executive Memory Mode
From the old days of DOS, what does the "EMM" in EMM386 stand for?

EXPLANATION

 EMM386 (software, storage)
An expanded memory manager for IBM PCs with an Intel 80386 or higher processor, part of MS-DOS version 5.00 or higher. EMM386 uses extended memory to simulate expanded memory and also provides upper memory blocks. It must be loaded by a DEVICE= command in your CONFIG.SYS file.

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Monday, July 13, 2020

In Linux system, which file contains the encrypted passwords of the users ?

In Linux system, which file contains the encrypted passwords of the users ?

  • /etc/crypttab
  • /etc/gshadow
  • /etc/shadow
  • /etc/password

 
In Linux system, which file contains the encrypted passwords of the users ?

EXPLANATION

In the Linux operating system, a shadow password file is a system file in which encrypted user password are stored so that they aren't available to people who try to break into the system.
Ordinarily, user information, including passwords, is kept in a system file called /etc/passwd.

SOURCE

http://searchsecurity.techtarget.com/definition/shadow-password-file
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