here is what you need to do

set span [source{port/vlan}] [destination port ] {here is where you put your options} create

if you do not add the create at the end the current span session will just be erased. if you add the create at the end a new session will be establised.

here is a list of the options.

[rx | tx | both] [inpkts {enable | disable}] [learning {enable | disable}] [multicast {enable | disable}]

"sho span" to verify config.

Mark Goodson