HCIA R&S H12-211 question about IPv6 MTU

Hi!

This is True.

Packets exceeding the size of the Maximum transmission unit (or MTU) of the destination link are dropped and this condition is signaled by a Packet too Big ICMPv6 type 2 message to the originating node, similarly to the IPv4 method when the Don't Fragment bit is set. End nodes in IPv6 are expected to perform Path MTU Discovery to determine the maximum size of packets to send, while the upper-layer protocol is expected to limit the payload size.

However, if the upper-layer protocol is unable to do so, the sending host may use the Fragment extension header in order to perform end-to-end fragmentation of IPv6 packets. Any data link layer conveying IPv6 data must at least be capable of delivering an IP packet containing up to 1280 bytes, thus the sending endpoint may limit its packets to 1280 bytes and avoid any need for Path MTU Discovery or fragmentation.