第2题: [简答题]What is the PMTUD for̳4;IPv6 network? 参考答案:
PMTUD is using to finding out the lowest MTU value along a path when a packet is sent to a destination to avoid fragmentation. PMTUD for IPv6 uses ICMPv6 error message Type 2, Packet Too Big, for its operation.
Fragmentation in IPv6 is not performed by intermediary routers. The source node may fragment packets by itself only when the path MTU is smaller than the packets to deliver.