AGRPORT_PROMISC
if (( promisc && (port->port_flags & AGRPORT_PROMISC) != 0) ||
(!promisc && (port->port_flags & AGRPORT_PROMISC) == 0)) {
port->port_flags |= AGRPORT_PROMISC;
port->port_flags &= ~AGRPORT_PROMISC;