ACtE08 · Chapter 8Mock Test 01🏛️ Past Licensure QuestionID: c68d936e
The subnet mask corresponding to a CIDR prefix of /15 is:
The subnet mask corresponding to a CIDR prefix of /15 is:
Multiple Choice Options
- A
255.240.0.0
- B
255.248.0.0
- C
255.252.0.0
- D✓ Correct Option
255.254.0.0
Detailed Technical Solution & Explanation
A CIDR prefix of /15 means that the first 15 bits of the 32-bit IPv4 address are network bits set to 1, followed by 17 host bits set to 0:
11111111 . 11111110 . 00000000 . 00000000
Converting to dotted-decimal notation:
•
1st octet:
•
2nd octet:
•
3rd & 4th octets:
Hence, the subnet mask is 255.254.0.0.
Option Analysis:
•
Option A (255.240.0.0): Incorrect; corresponds to a /12 prefix ().
•
Option B (255.248.0.0): Incorrect; corresponds to a /13 prefix ().
•
Option C (255.252.0.0): Incorrect; corresponds to a /14 prefix ().
•
Option D (255.254.0.0): Correct; exactly represents a /15 prefix.
Reference: Mock Test 01NEC Licensure Syllabus