Which IPv4 issue relates to fragmentation with small MTU?

• A. Large MTU fragmentation issues
• B. Routing table sizes unwieldy
• C. 32-bit address exhaustion
• D. Small MTU fragmentation issues

Answer: (D)

IPv4 fragmentation happens when a packet is larger than the MTU of the next hop, so routers split it into smaller fragments. When the path has a small MTU, this fragmentation happens more often, creating many fragments that each carry an IP header. That increases overhead, consumes memory for reassembly, and raises the chance that fragments are lost or delayed, which means the entire original packet may fail to be reassembled. If Path MTU Discovery isn’t able to learn a smaller workable MTU (for example, if the ICMP fragmentation-needed messages are blocked), packets can be dropped altogether. So the situation described by fragmentation with small MTU is exactly small MTU fragmentation issues—the issue arises specifically because the MTU is small and forces fragmentation. The other options don’t describe fragmentation dynamics tied to MTU size.