Your task is to troubleshoot a user’s PC with IP 10.20.30.5 and mask 255.255.255.0. Based on the given details type the number of the network (N), subnet (S), and host (H) bits.

(A) Network Bits = 16 | Subnet Bits = 15 | Host Bits = 1
(B) Network Bits = 16 | Subnet Bits = 1 | Host Bits = 15
(C) Network Bits = 8 | Subnet Bits = 8 | Host Bits = 16
(D) Network Bits = 8 | Subnet Bits = 16 | Host Bits = 8

Network Bits = 8 | Subnet Bits = 16 | Host Bits = 8 is the correct answer.

The size of the network part is always either 8, 16, or 24 bits, based on whether it is Class A, B, or C, respectively.
In this case, we have a Class A address, so the network part is 8bits. N = 8
The mask 255.255.255.0, converted to prefix format is /24. The number of subnet bits is the difference between the prefix length(24) and N(8).
S = prefix – N
S = 24 – 8 bits
S = 16
The number of the host bits is the total number of IP address bits(32) which is always 32bits minus the prefix length(28).
H = Adddres bits – prefix
H = 32 – 24
H = 8