Enabling or disabling router-advertisement (RA) messages enables you to control the routing configuration for selecting the correct network interface to communicate with its neighbors. The prefix information option in a RA message is used by the storage system to configure routes or autoconfigure IPv6 addresses as part of stateless autoconfiguration.
Therefore, default route is not learned dynamically, the default router failover is disabled, and link MTU updates stop. You can still configure default routes statically.
However, if you want to assign any autoconfigured address to a vFiler unit, then you must disable the RA address autoconfiguration prior to address assignment.
You should not statically configure the non-default vFiler units with the same IPv6 addresses that are generated by the autoconfiguration.