991 views

There is a need to create a network that has $5$ subnets, each with at least $16$ hosts. Which one is used as classful subnet mask ?

1. $255.255.255.192$
2. $255.255.255.248$
3. $255.255.255.240$
4. $255.255.255.224$

In all the classfull subnet mask option first three octet are same

Difference in last octet:

192 represent in binary : 11000000

4  subnet  and 62 host

248 represent in binary: 11111000

32 subnet and 6 host

240 represent in binary:  11110000

16 subnets and 14 hosts

224 represent in binary: 11100000

8 subnet and 30 hosts ( most suitable answer)

Option D is correct.

NOTE:

Here we need 5 subnet which is represent in No. Of 1's.

And atleast 16 hosts which is represented of no. Of 0's

### 1 comment

Minor issue, but the question didn’t state whether it’s going to be class $C$ addressing. But that is understood given the masks are $255.255.255.x$

1
1,239 views