Your assumption is correct. We are not using the Netapp CN1610 for a Netapp cluster switch. We have a single CN1610 switch installed with a twinax cable connected between the CN1610 and the Dell N series switch. Here are the current configs for each switch....
Dell N2048 port-channel config
interface port-channel 2
description "10g LAG to Netapp Cisco"
switchport mode trunk
switchport trunk allowed vlan 10,100
exit
Dell N2048 port config
interface Te1/0/2
channel-group 2 mode on
exit
Netapp CN1610 port-channel config
port-channel name 3/2 N2048-LAG
interface 0/1
no auto-negotiate
addport 3/2
interface 3/2
description 'N2048 LAG - port 1'
vlan participation include 10,100
lacp admin key 0
exit
Netapp CN1610 port config
interface 0/1
description 'LAG to N2048 switch'
exit
The lacp shows active on the Dell switch and it is sending PDU's. However, it is not receiving any PDU's from the CN1610.