Question

Host A (on TCP/IP v4 network A) sends an IP datagram D to host B (also on TCP/IP v4 network B). Assume that no error occurred during the transmission of D. When D reaches B, which of the following IP header field(s) may be different from that of the original datagram D?
(i) TTL
(ii) Checksum
(iii) fragment Offset

• A. (i), (ii) and (iii)
• B. (ii) and (iii) only
• C. (i) and (ii) only
• D. (i) only

Answer 1

The correct option is A (i), (ii) and (iii)

TTL changes from one hop to the next checksum changes on each hop due to TTL change.
Fragment offset may be computed again.
$\therefore$ TTL, check sum and fragment offset may be changed in the transmission.