Setting the interface MTU
About interface MTU
IPv6 routers do not support packet fragmentation. If a packet exceeds the MTU of the output interface, the router discards the packet and sends a packet too big message to the source host. This message contains the interface MTU. The source host fragments the packet according to the returned MTU. To avoid traffic overload due to packet dropping, set a proper interface MTU.
Procedure
Enter system view.
system-view
Enter interface view.
interface interface-type interface-number
Set the interface MTU.
ipv6 mtu size
By default, no interface MTU is set.