What IP address does localhost usually resolve to?

What IP address does localhost usually resolve to?

• 127.0.0.1
• 192.0.2.0
• 127.0.0.0
• 127.255.255.255 

 

EXPLANATION

  The IP address 127.0.0.1 is a special-purpose IPv4 address called localhost or loopback address. All computers use this address as their own but it doesn't let them communicate with other devices like a real IP address does.

Your computer might have the 192.168.1.115 private IP address assigned to it so that it can communicate with a router and other networked devices. However, it still has this special 127.0.0.1 address attached to it to mean "this computer," or the one you're currently on.

The loopback address is only used by the computer you're on, and only for special circumstances. This is unlike a regular IP address that is used to transfer files to and from other networked devices.

For example, a web server running on a computer can point to 127.0.0.1 so that the pages can be run locally and tested before it's deployed.

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OSI layer 1 corresponds to the:

OSI layer 1 corresponds to the:

• Application layer
• Physical layer
• Network layer
• Data link layer 

EXPLANATION

The Physical layer is also called as the Layer 1. Here are the basic functionalities of the Physical layer:

• Responsible for electrical signals, light signal, radio signals etc.
• Hardware layer of the OSI layer
• Devices like repeater, hub, cables, ethernet work on this layer
• Protocols like RS232, ATM, FDDI, Ethernet work on this layer

 

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In the OSI model, layer 3 corresponds to:

In the OSI model, layer 3 corresponds to:

• Data link layer
• Network layer
• Physical layer
• Transport layer 

EXPLANATION

The Network layer is also called as the layer 3 of the OSI model. Here are the basic functionalities of the network layer:

• Switching and routing technologies work here
• Creates logical paths between two hosts across the world wide web called as virtual circuits
• Routes the data packet to destination
• Routing and forwarding of the data packets.
• Internetworking, error handling, congestion control and packet sequencing work at this layer
• Router works at layer three
• Different network protocols like TCP/ IP, IPX, AppleTalk work at this layer

 

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A basic network switch that provides connections between LAN clients operates at which OSI layer?

A basic network switch that provides connections between LAN clients operates at which OSI layer?

• 3rd layer
• 1st layer [Physical Layer]
• 2nd layer
• 4th layer 

EXPLANATION

Layers of OSI model:

Physical layer

The Physical layer is also called as the Layer 1. Here are the basic functionalities of the Physical layer:

• Responsible for electrical signals, light signal, radio signals etc.
• Hardware layer of the OSI layer
• Devices like repeater, hub, cables, ethernet work on this layer
• Protocols like RS232, ATM, FDDI, Ethernet work on this layer

Data Link layer

The data link layer is also called as the Layer 2 of the OSI model. Here are the basic functionalities of the data link layer:

• Responsible for encoding and decoding of the electrical signals into bits.
• Manages data errors from the physical layer
• Convers electrical signals into frames
• The data link layer is divided into two sub-layers
  • The Media Access Control (MAC) layer
  • Logical Link Control (LLC) layer.
• The MAC sublayer controls how a computer on the network gains access to the data and permission to transmit it.
• The LLC layer controls frame synchronization, flow control and error checking.
• MAC address is a part of the layer 2.
• Devices like Switch work at this layer

Network Layer

The Network layer is also called as the layer 3 of the OSI model. Here are the basic functionalities of the network layer:

• Switching and routing technologies work here
• Creates logical paths between two hosts across the world wide web called as virtual circuits
• Routes the data packet to destination
• Routing and forwarding of the data packets.
• Internetworking, error handling, congestion control and packet sequencing work at this layer
• Router works at layer three
• Different network protocols like TCP/ IP, IPX, AppleTalk work at this layer

Transport layer

The Transport  layer is also called as the layer 4 of the OSI model. Here are the basic functionalities of the Transport layer:

• Responsible for the transparent transfer of data between end systems
• Responsible for end-to-end error recovery and flow control
• Responsible for complete data transfer.
• Protocols like SPX, TCP, UDP work here

Session layer

The Session  layer is also called as the layer 5 of the OSI model. Here are the basic functionalities of the Session layer:

• Responsible for establishment, management and termination of connections between applications.
• The session layer sets up, coordinates, and terminates conversations, exchanges, and dialogues between the applications at each end.
• It deals with session and connection coordination.
• Protocols like NFS, NetBios names, RPC, SQL work at this layer.

Presentation layer

The Presentation layer is also called as the layer 6 of the OSI model. Here are the basic functionalities of the presentation layer:

• Responsible for data representation on your screen
• Encryption and decryption of the data
• Data semantics and syntax
• Layer 6 Presentation examples include encryption, ASCII, EBCDIC, TIFF, GIF, PICT, JPEG, MPEG, MIDI.

Application Layer

The Application layer is also called as the layer 7 of the OSI model. Here are the basic functionalities of the Application layer:

• Application layer supports application, apps, and end-user processes.
• Quality of service
• This layer is responsible for application services for file transfers, e-mail, and other network software services.
• Protocols like Telnet, FTP, HTTP work on this layer.

 

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You want to combine four 1TB hard drives into a single array with at least 2TB of storage. Which of the below configurations gives you the best balance of performance and redundancy?

You want to combine four 1TB hard drives into a single array with at least 2TB of storage. Which of the below configurations gives you the best balance of performance and redundancy?

• RAID 6
• RAID 10
• JBOD
• RAID 5 

EXPLANATION

All of the above possible configurations provide the minimum storage requirement. Some configurations provide more storage than others, but this is not a requirement.
JBOD offers no redundancy or performance gains, but provides the most storage space of the options provided.
RAID 5 offers 3x read speed and no write performance gains. RAID 5 is fault tolerant to 1 disk, regardless of the number of

SOURCE

https://en.wikipedia.org/wiki/RAID

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Which of the following is NOT considered an "advanced threat"?

Which of the following is NOT considered an "advanced threat"?

• Zero-day attack
• Advanced persistent threat (APT)
• Zombieware [Please report if the answer is incorrect]
• Polymorphic malware 

EXPLANATION

A zero-day vulnerability is a computer-software vulnerability that is unknown to those who would be interested in mitigating the vulnerability. Until the vulnerability is mitigated, hackers can exploit it to adversely affect computer programs, data, additional computers or a network. An exploit directed at a zero-day vulnerability is called a zero-day exploit, or zero-day attack.

An advanced persistent threat is a set of stealthy and continuous computer hacking processes, often orchestrated by a person or persons targeting a specific entity. An APT usually targets either private organizations, states or both for business or political motives. 

 In computing, a zombie is a computer connected to the Internet that has been compromised by a hacker, computer virus or trojan horse program and can be used to perform malicious tasks of one sort or another under remote direction. Botnets of zombie computers are often used to spread e-mail spam and launch denial-of-service attacks (DOS attacks). Most owners of "zombie" computers are unaware that their system is being used in this way. Because the owner tends to be unaware, these computers are metaphorically compared to fictional zombies. A coordinated DDoS attack by multiple botnet machines also resembles a "zombie horde attack", as depicted in fictional zombie films.

Polymorphic Code is the debut studio album by French one-man band The Algorithm, signed by Basick Records and released on November 19, 2012. Music video for the song Trojans was released on November 7, 2012.

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Which of these is NOT a characteristic of a private cloud?

Which of these is NOT a characteristic of a private cloud?

• Users can self-provision
• Located on-premises
• Elastic and scalable
• Pay for only the resources you use 

EXPLANATION

The five characteristics of a private cloud:

1. Scalable: High levels of utilization (e.g., through virtualization, and the size and maturity of data centers)
2. Accessible: IT customers can self-provision
3. Elastic: Appearance of infinite capacity on demand
4. Shared: Workloads are multiplexed, capacity is pooled

5. Metered consumption: Ability to pay for use with no commitment

 

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