BARI Assistant Maintenance Engineer Exam: 26.08.2022প্রশ্ন ও সমাধান

Answer: 32 bits.

• An IPv4 address is a 32-bit number, conventionally written in dotted-decimal notation as four 8-bit octets separated by dots (e.g. 192.168.1.1), where each octet ranges from 0–255.
• 32 bits gives a theoretical address space of 2³² ≈ 4.29 billion unique addresses — a number that has since proven insufficient for the number of internet-connected devices worldwide, which is the core motivation behind IPv6 (128-bit addresses, ~3.4×10³⁸ addresses).

graph LR
    B["32 bits total"] --> O1["Octet 1 - 8 bits - 0-255"]
    B --> O2["Octet 2 - 8 bits - 0-255"]
    B --> O3["Octet 3 - 8 bits - 0-255"]
    B --> O4["Octet 4 - 8 bits - 0-255"]

Exam takeaway: IPv4 = 32-bit address (4 × 8-bit octets, dotted-decimal notation) → ~4.3 billion addresses, now largely exhausted, hence the shift to 128-bit IPv6.