how to communicate with a HP network analyzer through GPIB Ethernet controller

through NI Max, I am able to see my GPIB ethernet controller, but I am not able to see the instrument connected. I have the HP-IB address for the network analyzer as 

for 8751: 17

controller: 21

these were taken from the local properties of the instrument. In NI Max, under the general settings of the GPIB interface properties, what should I mention in the primary address and secondary address column to be able to communicate with my network analyzer. Moreover, should I keep the system controller option ticked or should I unmark it ?. Awaiting response asap.

Thanks in advance !!!