ip addrssing

Question

Using the following illustration, what would be the IP address of E0 if you were using the eighth subnet? The network ID is 192.168.10.0/28 and you need to use the last available IP address in the range. The zero subnet should not be considered valid for this question.

A. 192.168.10.142 B. 192.168.10.66 C. 192.168.100.254 D. 192.168.10.143 E. 192.168.10.126

Answer 1

Answer should be A because

network id is 192.168.10.0/28, which means class C

Hence network id bits are 24

Subnet id bits = 28-24 = 4

and remaining 4 bits for host id.

192.168.10.0 is  11000000 . 10101000 . 00001010 . 0000 0000

Since, zero subnet should not be considered valid for this question

Eighth subnet is 1000

and last available host id is 1110

Hence last available ip address is 11000000 . 10101000 . 00001010 . 1000 1110 which is 192.168.10.142

Comments

192.168.10.0/28    where /28 is the CIDR  notation . It is classless  .can we represent  class full too with slash  (/) notation .

Check  it once please and notify me where  I am wrong

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This is classless you can observe onle mask and I'd

Fir you should convert both into binary

And find in last octal 4+4bits

Which represent subnet bits and host bits

We need 8th subnet=1000

Last host=1110

Last octal will be 10001110

Equal to 142

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@ Nitesh choudhry

This is classless the reason is its notation clearly says that. now it has mentioned thaupto  28 bits it will be contineous 1 which will be considered as network part  ,so raming bits on that we can apply subnetting is 4 bits .bcz only 4 bits are there in host part . and subnetting can be applied on host part only.

 

now in that 4 bits , how is 8th subnet possible.?

what is Zero subnet here ??