If a Class B network on the internet has a subnet mask of 255.255.248.0, what…
2024
If a Class B network on the internet has a subnet mask of 255.255.248.0, what is the maximum number of hosts per subnet?
- A.
1023
- B.
1022
- C.
1024
- D.
2046
- E.
Question not attempted
Attempted by 155 students.
Show answer & explanation
Correct answer: D
We are given a subnet mask: 255.255.248.0
Let’s analyze it using Class B IP addressing logic.
Step 1: Convert subnet mask to prefix
255.255.248.0 in binary:
255 = 8 bits
255 = 8 bits
248 = 11111000 → 5 bits
0 = 8 bits
So total network bits =
👉 8 + 8 + 5 = 21 bits
So subnet mask = /21
🔍 Step 2: Host bits
IPv4 has 32 bits total:
Host bits = 32 − 21 = 11 bits
🔍 Step 3: Calculate usable hosts
Formula:
2host bits −2
211 − 2=2048−2=2046
⚠️ Important correction
We must be careful:
Since it is a Class B network, default is /16, but mask is /21 → still correct subnet calculation is valid.
However, the question asks maximum hosts per subnet, so we use correct host bits = 11.
👉 So correct answer = 2046