Question

QUESTION 6

1. What is the dotted decimal representation of an 8-bit netmaks?

   a		255.255.255.255
   b		255.0.0.0
   c		255.255.0.0
   d		255.0.0.255
   e		0.0.0.255

10 points   

QUESTION 7

1. If you receive a Request timed out error message when using ping, what would you attempt next?

   a		nmap
   b		metasploit
   c		ipconfig
   d		route
   e		tracert

10 points   

QUESTION 8

1. What does the server generate when a message via SMTP cannot be delivered?

   a		NSA
   b		NDR
   c		HTTPS
   d		LOL
   e		NXDOMAIN

IT'S URGENT!!! Please answer in 15m or less.

WILL BE DEFINITELY UPVOTED!

Answer 1

Q6) answer is (b)

the meaning of 8-bit netmask means it’s the length of the netmask

Calculation of subnet mask length:

· Convert the dotted representation in decimal to binary numbers

· Then count the number of contiguous 1 bits from the left side of the netmask, that is from the most significant bit onwards

Now lets check the length of netmask of all given options

a) 255.255.255.255 = 11111111 11111111 11111111 11111111 (equivalent binary representation)

So the total number of contiguous 1 bit = 32

So its 32 bit netmask

b) 255.0.0.0 = 11111111 00000000 00000000 00000000

Here from the above criteria of length calculation , the length is 8 bits

Which is the answer for the question.

c) 255.255.0.0 = 11111111 11111111   00000000 00000000

Length = 16 bits

d) 255.0.0.255 ,this is a kind of wildcard mask

Means, the wildcard mask are used to say about the scope of address filter.

Its used when the subnet mask has to be filtered, then the corresponding fixed wildcard for that subnet mask are used.

Here the calculation is different, the bits to be cared is 0 bits

1 bits are don’t care bits.

So 255.0.0.255 = 11111111 00000000 00000000 11111111

So here count the contiguous number of 0 bits which is 16 here

e) 0.0.0.255 = 00000000 00000000 00000000 11111111

So here also it’s a wildcard mask, so the calculation is different as mentioned above

So the given mask is 24 bits

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Q7) answer is (c)

a)nmap is a tool used to map the network, like to check for the host which are live on the network ,scan the port etc.

b)metasploit is a tool used for computer security.

c)ipconfig: if there is request time out error comes, then the next step is to trace the route and ipconfig is used for this.

This helps to :

· Determine local IP address

· Subnet mask

· Gateway address

· Other network configuration.

d)route command is used to manually enter the data into network routing tables.

e)tracert: is a command to solve the routing problems of the computer.

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Q8) answer (b)

a)NSA: deals with the servers of national security agency

b)NDR : non-delivery report, which is a DSN or delivery status notification or bounce message send to say about the status of the delivery of messages via SMTP, its shows that the intended message has not be delivered.

c) HTTP: its an application layer protocol

d)LOL : no association is seen with LOL and message passing

e)NXDOMAIN: is a DNS error message type saying the domain doesnot exist