In computer networking, which of the following IPv4 addresses falls within the private address ranges reserved by RFC 1918?

Introduction / Context:
IPv4 defines special “private” address blocks that can be used inside local area networks without consuming globally routable space. Routers on the public Internet do not forward these addresses. Knowing the exact ranges is essential for subnetting, home/enterprise network design, and troubleshooting Network Address Translation (NAT).

Given Data / Assumptions:

• The question lists four dotted-decimal IPv4 addresses.
• Private ranges per RFC 1918 are: 10.0.0.0–10.255.255.255, 172.16.0.0–172.31.255.255, and 192.168.0.0–192.168.255.255.
• Any address outside those ranges is public (barring other special-use blocks).

Concept / Approach:
Compare each option to the three private blocks and identify which one falls inside. Use inclusive range checks on the second octet for the 172.16/12 block and on the third octet for the 192.168/16 block.

Step-by-Step Solution:

Verification / Alternative check:
Quick mask method: 192.168.24.43 AND 255.255.0.0 equals 192.168.0.0; the network is within 192.168.0.0/16, a private block. None of the others match 10/8, 172.16/12, or 192.168/16.

Why Other Options Are Wrong:
12.0.0.1: A routable public block owned by providers.
168.172.19.39: Public address space.
172.15.14.36: The private 172 range starts at 172.16, so 172.15 is not private.

Common Pitfalls:
Confusing 172.15 with 172.16–31 due to similar prefix; forgetting that only 172.16 through 172.31 are private. Also, assuming any 192.x address is private—only 192.168.x.x qualifies under RFC 1918.

Final Answer:
192.168.24.43