First, check connectivity.
Afterwards check: vlan tagging (netapp and switch compliant to each other), did you made the vif using lacp but didn't configured the switch's ports to lacp, is it lacp but to different switches (won't work), subnet, if you type vif status (or ifgrp status, depends on your ONTAP version) do you that the links are up or are the down\broken ?
A lot of reasons may set you back, it needs a closer look
