Define MTU and fragmentation. When does fragmentation occur and what issues can fragmentation cause?

• A. MTU is the maximum frame size on a link; fragmentation occurs when packets exceed MTU; IPv4 fragmentation can occur on routers; IPv6 fragmentation is done by the source; fragmentation can cause inefficiency and PMTUD challenges.
• B. MTU is the minimum guaranteed packet size on a link.
• C. Fragmentation never happens in IPv4.
• D. Fragmentation is always beneficial for performance.

Answer: (A)