Binary to dotted-decimal conversion of an IPv4 address Convert the 32-bit address 10000000 00001010 00000010 00011110 to dotted-decimal form.

Introduction / Context:
IPv4 addresses are commonly written in dotted-decimal notation, but under the hood they are 32-bit binary values split into four octets. Network engineers and students must be fluent in converting between binary and dotted-decimal formats for subnetting, routing, and troubleshooting.

Given Data / Assumptions:

• The binary address is 10000000 00001010 00000010 00011110.
• Each group of 8 bits represents one octet.
• We convert each octet from binary to decimal independently.

Concept / Approach:

Break the 32-bit binary string into four octets. Convert each octet from base 2 to base 10 using positional weights (128, 64, 32, 16, 8, 4, 2, 1). Concatenate the four decimal values using dots between them to form dotted-decimal notation.

Step-by-Step Solution:

Verification / Alternative check:

Use a calculator or quick mental conversion: the presence of a single leading 1 in the first octet confirms 128; the second octet has bits at 8 and 2 positions; the third only at 2; the fourth at 16, 8, 4, and 2. Everything matches the final value 128.10.2.30.

Why Other Options Are Wrong:

• 210.20.2.64, 164.100.9.61, 148.20.2.30: do not correspond to the given binary octets.
• None of the above: incorrect because 128.10.2.30 is correct.

Common Pitfalls:

Misgrouping bits into octets, treating binary as a single big-endian integer without splitting, or miscalculating weights (for example, forgetting that the leftmost bit is 128 in an octet). Practice with common patterns improves speed and accuracy.

Final Answer:

128.10.2.30