@param context - sender context, to match reply w/ request
@param tunnel_type - 0: L3, 1: TEB, 2: ERSPAN
@param instance - optional unique custom device instance, else ~0.
@param context - sender context, to match reply w/ request
@param tunnel_type - 0: L3, 1: TEB, 2: ERSPAN
@param instance - optional unique custom device instance, else ~0.