net/bonding - need for 8023ad slave to be in promisc mode

Hi folks,

Could someone clarify the need to put mode 4 bonding slaves in promiscuous
mode?

840 void
841 bond_mode_8023ad_activate_slave(struct rte_eth_dev *bond_dev, uint8_t
slave_id)
842 {
 .
 .
 .
878     /* use this port as agregator */
879     port->aggregator_port_id = slave_id;
880     rte_eth_promiscuous_enable(slave_id);


The Linux kernel mode bonding driver gets it working by assigning the
bond/primary slave MAC address to the rest of the slaves.  Is there a
reason for not using this method?

I tried this using my app on DPDK 16.04 on 82599, but could not get rx
working.  It would be great if someone could help me with this.

Thanks,
-Sujith