Which field in IPv4 fragmentation shows a fragment's starting position in the original payload?

• A. Fragment Offset
• B. Identification
• C. Version
• D. Header Length

Answer: (A)

Fragment Offset is the field that tells where the fragment’s data begins in the original payload. When an IPv4 datagram is split into smaller pieces, each fragment carries its own offset value, expressed in 8-byte units. The first fragment has an offset of zero, and subsequent fragments use the offset to indicate where their data fits within the original datagram. This offset, together with each fragment’s data length, lets the destination reassemble the complete payload in the correct order. The other fields help with identification (which fragments belong together) or indicate protocol version and header size, but they do not specify the fragment’s starting position within the original payload.