Networking - Subnetting - Discussion
Discussion Forum : Subnetting - Subnetting (Q.No. 5)
5.
You need to subnet a network that has 5 subnets, each with at least 16 hosts. Which classful subnet mask would you use?
Answer: Option
Explanation:
You need 5 subnets, each with at least 16 hosts. The mask 255.255.255.240 provides 16 subnets with 14 hosts-this will not work. The mask 255.255.255.224 provides 8 subnets, each with 30 hosts. This is the best answer.
Discussion:
26 comments Page 1 of 3.
Czar said:
6 years ago
5 subnets 16 hosts
First, you have to meet the number of the host which is 16. By borrowing 4 bits we will meet 16 hosts but there will be no room for the network and broadcast address so we will use 5 bits that has 32 hosts. Using the 2^5 -2 will give us 30 which satisfy our required number of hosts.
Secondly, we will use the formula an actual number of network = 32 (by default) minus no. of borrowed bits so 32-5 equals 27.
Our new subnet mask is /27 which is equivalent to 255.255.255.224.
First, you have to meet the number of the host which is 16. By borrowing 4 bits we will meet 16 hosts but there will be no room for the network and broadcast address so we will use 5 bits that has 32 hosts. Using the 2^5 -2 will give us 30 which satisfy our required number of hosts.
Secondly, we will use the formula an actual number of network = 32 (by default) minus no. of borrowed bits so 32-5 equals 27.
Our new subnet mask is /27 which is equivalent to 255.255.255.224.
(3)
Peeyush said:
10 years ago
As we require 16 Host in each subnet. We will first check Binary Table.
128 64 32 16 8 4 2 1.
If we take 16 we will not get 16 usable IP we will only get 14 usable IP. 2 ID will be taken for Subnet id and Broadcast ID.
So will take 32.
Now if we check mask it will be created like below:
11111111.11111111.11111111.11100000
By converting this into decimal it will then become: 255.255.255.224
This is the right answer.
128 64 32 16 8 4 2 1.
If we take 16 we will not get 16 usable IP we will only get 14 usable IP. 2 ID will be taken for Subnet id and Broadcast ID.
So will take 32.
Now if we check mask it will be created like below:
11111111.11111111.11111111.11100000
By converting this into decimal it will then become: 255.255.255.224
This is the right answer.
Gopi Kanaparthi said:
9 years ago
Class c default subnet mask \24 like 255.255.255.0
Example:
Converting bit 1, n=2^1=2.
Converting bit 2, n=2^2=4.
Converting bit 3, n=2^3=8.
So first converting bit 1 is two subnets, second one is 4 subnets and third one is 8
Subnets support. We want 5 subnets so by using 3 converting bits.
Default network bits+converting bits, N+n = 24+3 = 27.
By using subnetmask 255.255.255.224
Example:
Converting bit 1, n=2^1=2.
Converting bit 2, n=2^2=4.
Converting bit 3, n=2^3=8.
So first converting bit 1 is two subnets, second one is 4 subnets and third one is 8
Subnets support. We want 5 subnets so by using 3 converting bits.
Default network bits+converting bits, N+n = 24+3 = 27.
By using subnetmask 255.255.255.224
Hagos said:
1 decade ago
255.255.255.224 in binary would be written as:
11111111.11111111.11111111.11100000.
To find number of host:
Starting from the octet consisting both 1 and 0.
Count number of zeros to the end of the subnet mask.
The last octet consist of 5 zeros therefore.
2^h-2 (h = number of zeros) = 2^5-2 = 32 -2 = 30.
To find number of sub nets:
2^n (n = number of ones) 2^3 = 8.
11111111.11111111.11111111.11100000.
To find number of host:
Starting from the octet consisting both 1 and 0.
Count number of zeros to the end of the subnet mask.
The last octet consist of 5 zeros therefore.
2^h-2 (h = number of zeros) = 2^5-2 = 32 -2 = 30.
To find number of sub nets:
2^n (n = number of ones) 2^3 = 8.
Fariha said:
10 years ago
Suppose you are given the following class C IP address: 192.100.1.1. You need to perform Subnetting in such a way that you get 3 (three) subnets such that each subnet contains 62 (sixty two) valid hosts.
You need to specify the network and broadcast address of each subnet and the valid host range in each of the subnet. Please solve it as early as possible.
You need to specify the network and broadcast address of each subnet and the valid host range in each of the subnet. Please solve it as early as possible.
Abhishek Jha said:
3 years ago
16 hosts < 32, 32 = 2^5, so it takes 5 bits, and each subnet has 30 hosts.
32 " 5 = 27, it means the subnet-mask has /27 bits.
5 subnets < 8, 8 = 2^3,
therefore, 27 " 3 = 24 bits,
= 255.255.255.0.
8 subnets x 32 IPs " 2 = 254, the answer should be 255.255.255.0.
For example class c IP, 192.168.1.1/24 with subnet-mask 255.255.255.224.
32 " 5 = 27, it means the subnet-mask has /27 bits.
5 subnets < 8, 8 = 2^3,
therefore, 27 " 3 = 24 bits,
= 255.255.255.0.
8 subnets x 32 IPs " 2 = 254, the answer should be 255.255.255.0.
For example class c IP, 192.168.1.1/24 with subnet-mask 255.255.255.224.
Jayden said:
4 years ago
16 hosts < 32, 32 = 2^5, so it takes 5 bits, and each subnet has 30 hosts.
32 " 5 = 27, it means the subnet-mask has /27 bits.
5 subnets < 8, 8 = 2^3,
therefore, 27 " 3 = 24 bits,
= 255.255.255.0.
8 subnets x 32 IPs " 2 = 254, the answer should be 255.255.255.0.
For example class c IP, 192.168.1.1/24 with subnet-mask 255.255.255.224.
32 " 5 = 27, it means the subnet-mask has /27 bits.
5 subnets < 8, 8 = 2^3,
therefore, 27 " 3 = 24 bits,
= 255.255.255.0.
8 subnets x 32 IPs " 2 = 254, the answer should be 255.255.255.0.
For example class c IP, 192.168.1.1/24 with subnet-mask 255.255.255.224.
Angel said:
10 years ago
Suppose you are given the following class C IP address: 192.100.1.1. You need to perform Subnetting in such a way that you get 3(three) subnets such that each subnet contains 62 (sixty two) valid hosts. You need to specify the network and broadcast address of each subnet and the valid host range in each of the subnet.
solve it and give answer
solve it and give answer
Chaithanya katari said:
8 years ago
225.255.255.192=/26 so 24+2(2N we need to borrow) formula 2^2=4 subnets.
for hosts 256-192=64 hosts.
255.255.255.224=/27 so 24+3(3n we need to borrow)formula 2^n=2^3=8 sub.
for hosts 256-224=32 hosts.
255.255.255.240=/28 so 24+4(4N we need to borrow) formula 2^N=16 subnets.
for hosts 256-240=16 hosts.
for hosts 256-192=64 hosts.
255.255.255.224=/27 so 24+3(3n we need to borrow)formula 2^n=2^3=8 sub.
for hosts 256-224=32 hosts.
255.255.255.240=/28 so 24+4(4N we need to borrow) formula 2^N=16 subnets.
for hosts 256-240=16 hosts.
(1)
Mack said:
10 years ago
Please tell me if I'm wrong, but another way to think of it is:
128 64 32 16 8 4 2 1.
1 1 1 0 0 0 0 0.
32 is the smallest bit used so.
32 - 1 (domain) - 1 (server) = 30.
Honestly, I think I remember seeing it this way in a tutorial, so if I'm wrong please correct and/or email me.
128 64 32 16 8 4 2 1.
1 1 1 0 0 0 0 0.
32 is the smallest bit used so.
32 - 1 (domain) - 1 (server) = 30.
Honestly, I think I remember seeing it this way in a tutorial, so if I'm wrong please correct and/or email me.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers