Hi,
The C9500-DNA-L-A-3Y includes both Perpetual Network Advantage and a term-based (3-, 5-, or 7-year) Cisco DNA Advantage package.
All the Perceptual Network Advantage license will continue to work even after 3 Years.Only if DNA Features are used renewal is necessary.
No option from Cisco yet to purchase only Network Advantage only.
DNA Advantage is mandatory,
Hope this helps ,