Add this line in the /etc/driver/drv/i40e.conf
file and reboot the server.
default_mtu =desired-frame-size;
where desired-frame-size value can range
from 1500 to
9706.
Note -
Adding this line will make changes to all instances of i40e. To
change for specific instances, see Step 2 in Set Driver Parameters
(Oracle Solaris).