nd they marked the answer ad 190

The Gateway to Computer Science Excellence

First time here? Checkout the FAQ!

x

0 votes

+1 vote

00--- subnet id

01--- first subnet

10---2nd subnet

11---3rd subnet

Example:

0

in one of the question of ace test series they asked the fourth octet of last ip address of the 3rd subnet for a class c network with subnet mask /26..

nd they marked the answer ad 190

nd they marked the answer ad 190

+2

@abhisheskmehta when we do subnetting we assume that for 2 bit(2^2-2=2 subnets) subnetting that 00 goes for 0th subnet and 01 (first subnet ) 10 (second subnet) and last one 11(DBA subnet) (we assume that network itself will not participate in subnetting).So how can u say that 11 is third subnet?If we assume that network can participate in subnetting then 2^2=4 subnets and 00(first subnet) 01(second subnet) 10(third subnet) 11(4th subnet).correct me if i am wrong.

0

Its little bit ambiguous . But In gate question it is given first id is subnet id or total number of subnet = 2^n -2 .

0

so as of now there will not be third subnet for the given question because we follow the assumption that number of subnets=2^n-2 so only first and second subnets are possible.correct me if i am wrong.

0

what if the network has suppose 200 ip and we divide it as

1st subnet :- 100 ip

2nd subnet :- 50 ip

3rd subnet :- 50 ip.

Then we can divide the network into 3 subnets.

1st subnet :- 100 ip

2nd subnet :- 50 ip

3rd subnet :- 50 ip.

Then we can divide the network into 3 subnets.

0

@sabir this can be done using 2 bits with the help of variable length subnetting.two choices might be there, subnetting bit as 1 for first subnet and 00 for second subnet and 01 for third subnet or 0 for first subnet and 10 for second subnet and 11 for third subnet.thisquestion is different from the given question.

0 votes

It depends upon the way in which you want to divide the network into subnets.

Eg:- 200.254.254.0/26 is a class C network having 2 bits for subnet ID.

NOTE:- /26 is CIDR value which means number of 1s in the subnet mask.

In this the first 2 bits of last octet are for subnet i.e. 200.254**.**254**.00**000000.

Now if you want to divide this network into two equal subnets then we need only the 1st bit of subnet bit and it would be divided as

200.254.254.**0**/25 to 200.254.254.**127**/25 -----> subnet 1--------> 200.254. 254 .**0**0000000/25 to 200.254. 254 .**0**1111111/25.

200.254.254.**128**/25 to 200.254.254.**255**/25 ---------> subnet 2------> 200.254. 254 .**1**0000000/25 to 200.254. 254 .**1**1111111/25.

if you want to divide subnet 1 into two equal subnets then we need the 1st and 2nd bit of subnet bit and it would be divided as

200.254.254.**0**/26 to 200.254.254.**63**/26 -----> subnet 3--------> 200.254.254.**00**000000/26 to 200.254.254.**00**111111/26.

200.254.254.**64**/26 to 200.254.254.**127**/26 -----> subnet 4--------> 200.254.254.**01**000000/26 to 200.254.254.**01**111111/26.

Similarly, if you want to divide subnet 2 into two equal subnets then we need the 1st and 2nd bit of subnet bit and it would be divided as

200.254.254.**128**/26 to 200.254.254.**191**/26 -----> subnet 5--------> 200.254.0.**10**000000/26 to 200.254.254.**10**111111/26.

200.254.254.**192**/26 to 200.254.254.**255**/26 -----> subnet 6--------> 200.254.254.**11**000000/26 to 200.254.254.**11**111111/26.

- All categories
- General Aptitude 1.5k
- Engineering Mathematics 7.1k
- Digital Logic 2.7k
- Programming & DS 4.9k
- Algorithms 4.2k
- Theory of Computation 5.3k
- Compiler Design 2.1k
- Databases 4k
- CO & Architecture 3.5k
- Computer Networks 4k
- Non GATE 1.4k
- Others 1.5k
- Admissions 556
- Exam Queries 551
- Tier 1 Placement Questions 23
- Job Queries 69
- Projects 18

47,894 questions

52,261 answers

182,169 comments

67,679 users