In IPv4 addressing, which range represents the Class C private IP address space as defined by RFC 1918?

Introduction / Context:
This question tests your understanding of private IP address ranges in IPv4, specifically the block commonly referred to as the Class C private address space. Knowing which ranges are reserved for private use is essential for designing internal networks, configuring Network Address Translation, and avoiding conflicts with public Internet address space.

Given Data / Assumptions:
- We are working with IPv4, not IPv6.
- The question refers to the historic classful terminology, but modern networks still use the same private ranges defined by RFC 1918.
- RFC 1918 defines three private ranges: one traditionally associated with Class A, one with Class B, and one with Class C.
- We must identify the range that corresponds to the Class C style private block.

Concept / Approach:
RFC 1918 defines the following private IPv4 address ranges:

• 10.0.0.0/8 (commonly called the Class A private range).
• 172.16.0.0/12 (commonly called the Class B private range).
• 192.168.0.0/16 (commonly called the Class C private range).

The Class C terminology comes from the original classful idea that Class C networks start at 192.0.0.0 and run through 223.255.255.255, with many small networks. The reserved private part of this spectrum is 192.168.0.0 to 192.168.255.255.

Step-by-Step Solution:
Step 1: Recall the three RFC 1918 private blocks: 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.Step 2: Associate 10.0.0.0/8 with the traditional Class A space because it covers the entire first octet 10.Step 3: Associate 172.16.0.0/12 with the traditional Class B space because it spans a range of contiguous Class B networks.Step 4: Recognize that 192.168.0.0/16 is the private range that sits in the historic Class C portion of the IPv4 address space.Step 5: Translate the 192.168.0.0/16 prefix into the explicit range 192.168.0.0 through 192.168.255.255.

Verification / Alternative check:
You can verify this by thinking about common home and small office routers, which often default to networks such as 192.168.0.0/24 or 192.168.1.0/24. These are subnets of the larger 192.168.0.0/16 private block. In contrast, large enterprise networks often use 10.0.0.0/8 because it offers a very large internal address space, and some organizations use the 172.16.0.0/12 range for medium sized deployments.

Why Other Options Are Wrong:
10.0.0.0/8 is a private range but is the Class A style private block, not the Class C space. 172.16.0.0/12 is the Class B style private block. 169.254.0.0/16 is used for Automatic Private IP Addressing when Dynamic Host Configuration Protocol is unavailable and is not an RFC 1918 private range in the same sense. The 224.0.0.0 to 239.255.255.255 block is Class D, reserved for multicast, not for private unicast addressing.

Common Pitfalls:
A common mistake is to assume that any address starting with 192 is private or that 169.254.0.0/16 is part of RFC 1918. Another pitfall is to forget the exact boundaries of the 172.16.0.0/12 range and incorrectly label it as Class C style. Remembering the three canonical private ranges exactly as 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 helps avoid these errors.

Final Answer:
The Class C private IP address space is 192.168.0.0 to 192.168.255.255, which is the 192.168.0.0/16 block.