A network administrator is verifying the configuration of a newly installed host by establishing an FTP connection to a remote server. What is the highest layer of the protocol stack that the network administrator is using for this operation?

A network administrator is verifying the configuration of a newly installed host by establishing an FTP connection to a remote server. What is the highest layer of the protocol stack that the network administrator is using for this operation?

• Application
• Transport
• Presentation
• Session 

EXPLANATION

An application layer is an abstraction layer that specifies the shared communications protocols and interface methods used by hosts in a communications network. The application layer abstraction is used in both of the standard models of computer networking: the Internet Protocol Suite (TCP/IP) and the OSI model.

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What was the first computer virus in the DOS system?

What was the first computer virus in the DOS system?

• I Love You Virus
• Storm Worm Virus
• Melissa Virus
• Brain Virus 

EXPLANATION

 The 1986 Brain virus is considered to be the first computer virus to infect MS-DOS and PC-DOS. It was transmitted through an infected boots sector of a floppy disk, and was originally intended to detect and track pirated copies of the authors’ floppy-based software. Unlike most modern malware, the virus included contact information for the authors. You can read more about the Brain virus here

Of course, other viruses on other platforms predated the Brain virus. The Elk Cloner virus for the Apple II appeared five years earlier, in 1981. It was also a floppy disk boot sector virus, which infected Apple DOS 3.3. And ten years before that, in 1971, the Creeper virus made its way through the ARPANET to infect DEC PDP-10 mainframe computers running the TENEX operating system. There are other examples as well, but these are considered “firsts.”

Recorded experimental work in academia with self-replicating programs dates as far back as 1949. Most of the academic efforts were never released into the wild.

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Which command can be used in PowerShell but not in CMD?

Which command can be used in PowerShell but not in CMD?

• CD
• LS
• TREE
• DIR

EXPLANATION

PowerShell is mostly used by system administrators to manage the network as well as the systems and applications that are part of that network. It can efficiently interpret both Batch command and PowerShell commands, whereas cmd can interpret only Batch commands

PowerShell is a cross-platform solution, which means that now you can run it, of course, on Windows, but also on several different Linux distributions, on MacOSX 10.12 and also on the ARM platform! 

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Which of these applications is included in an Office 365 E3 License?

Which of these applications is included in an Office 365 E3 License?

• OneNote
• Access
• Visio
• Project

EXPLANATION

Office 365 E3

• Includes full desktop versions of Office apps

• Each user can install Office mobile apps on 5 PCs or Macs, 5 tablets, and 5 phones

• Five layers of security and monitoring help keep customer data safe

• Reduce IT costs, and move to the cloud on your terms

• Guaranteed 99.9% uptime, and 24/7 support from Microsoft

Office 365 E3 includes

• Word
• Excel
• PowerPoint
• Outlook
• OneNote
• SharePoint
• OneDrive
• Microsoft Teams

 

 

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A PC has physical connections to two seperate networks/ subnets. One subnet has internet access, the other is an isolated test network. When the test network is connected the working internet connection fails. What is the issue, how do you know?

A PC has physical connections to two seperate networks/ subnets. One subnet has internet access, the other is an isolated test network. When the test network is connected the working internet connection fails. What is the issue, how do you know?

• There is a broadcast storm on the isolated network, rapid activity lights blinking on connection.
• A PC can't be a member of multiple subnets at once, the internet works when test network is offline
• A route for the isolated network has a metric < or = to internet connection, use route print command
• The PC has an invalid default gateway on the isolated network and can't connect to another network. 

EXPLANATION

2 PC's.
PC1 = 192.168.20.1/24
PC2 = 192.168.30.1/24

PC1 wants to ping PC2
The first thing it does is compare the IP address of PC2 with its own IP/subnetmask. It realises that PC2 is on another network.
PC1 checks its routing table to se if it has a route to PC2's subnet. Most likely it does not. But it should have a default route.
So what PC1 does is do an ARP for the default gateways IP and gets the MAC of the default address. (if it doesnt have a default gateway it then drops the ping)

PC1 then encapsulates the ping (icmp) in a ethernet frame with a destination address = MAC address of default gateway.

So when the ethernet frame arrives at the L2 switch it forwards the frame to the default gateway. NOT PC2.

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