Network Layer- Subnetting Question or MCQ-9

Q 9 How many subnet & Host are available for Network Address 172.8.9.3/18 ? find Subnet Mask Also ?

(a) 8 Subnet , 8 Host & 255.255.255.252

(b) 2 Subnet , 32896 Host & 255.255.128.0

(c) 4 Subnet , 16382 Host & 255.255.192.0

(d) 8 Subnet , 4096 Host & 255.255.255.252

Answer :- (c)

Explanation

CIDR 18 Means 18 Network bit will one and 14 Host bit will be Zero
so Correct mask is
Binary Representation
11111111.11111111.11000000.00000000
Decimal Representation
255.255.192.0

Total Subnets 2²=4

Maximum number of Hosts in every subnet is 2¹⁴=16,384

Usable host 16,384-2=16,382 (i.e. First and Last Host will be reserved for Network id and Broad Cast Address)

Correct Answer (c) 4 Subnets is there in each subnet Available Host will be 16,382 and Subnet Mask would be 255.255.192.0