Jumbo frames can support up to 9500 MTU. The default value is 1500 MTU.
For example, where the IP address for eth7 is 192.1.1.200, this command increases MTUs to the maximum:
# ifconfig eth7 192.1.1.200 mtu 9500 up
For more information, refer to the Oracle Solaris ifconfig(1M) man page.