RTU does not forward broadcast frames (FF:FF:FF:FF:FF:FF) to CPU
Even executing the following in RTU does not enable forwarding
rtu_learn_enable_on_port(18, 1);
rtu_pass_all_on_port(18, 1);
rtu_unset_fixed_prio_on_port(18);
rtu_set_unrecognised_behaviour_on_port(18, 1);
An addition of enabling HP mask does the job:
wrs_vlans --hpmask 0xff