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What is the significance of path minimum transmission unit MTU and how does it work in IPv6?
A larger MTU size means that fewer packets are required to transmit a certain amount of data. To achieve the best data transmission performance, IPv6 data packets sent from one node (the source) to another node (the destination) should be the largest possible size that can traverse the path between the nodes.
Why is fragmentation necessary in IPv6?
The IPv6 sender may perform fragmentation at source because an IPv6 router cannot perform a fragmentation, so if packet is too large for next hop, router will generate an ICMP packet to let the source know that packet is too large in size.
What is the minimum MTU for IPv6 packets in bytes?
1280 bytes
IPv6 requires that the link layer support a minimum MTU size of 1280 bytes. Link layers that do not support this MTU size must provide a link-layer fragmentation and reassembly scheme that is transparent to IPv6.
How does path MTU discovery work in IPv6?
As in IPv4, path MTU discovery in IPv6 allows a host to dynamically discover and adjust to differences in the MTU size of every link along a given data path. In IPv6, however, fragmentation is handled by the source of a packet when the path MTU of one link along a given data path is not large enough to accommodate the size of the packets.
What should the minimum MTU be for IPv6?
Having IPv6 hosts handle packet fragmentation saves IPv6 device processing resources and helps IPv6 networks run more efficiently. In IPv6, the minimum link MTU is 1280 octets. We recommend using an MTU value of 1500 octets for IPv6 links.
Do you need a Cisco account for MTU Discovery?
An account on Cisco.com is not required. As in IPv4, path MTU discovery in IPv6 allows a host to dynamically discover and adjust to differences in the MTU size of every link along a given data path.
How is the path MTU determined in ICMP?
The process is repeated until the MTU is small enough to traverse the entire path without fragmentation. If the Path MTU changes after the connection is set up and is lower than the previously determined Path MTU, the first large packet will cause an ICMP error and the new, lower Path MTU will be found.