NM_BDG_MAXRINGS
nm_bound_var(&na->num_tx_rings, 1, 1, NM_BDG_MAXRINGS, NULL);
nm_bound_var(&na->num_rx_rings, 1, 1, NM_BDG_MAXRINGS, NULL);
num_dstq = NM_BDG_MAXPORTS * NM_BDG_MAXRINGS + 1;
dsts = (uint16_t *)(dst_ents + NM_BDG_MAXPORTS * NM_BDG_MAXRINGS + 1);
d_i = dst_port * NM_BDG_MAXRINGS + dst_ring;
brddst = dst_ents + NM_BDG_BROADCAST * NM_BDG_MAXRINGS;
d_i = i * NM_BDG_MAXRINGS;
dst_na = b->bdg_ports[d_i/NM_BDG_MAXRINGS];
dst_nr = d_i & (NM_BDG_MAXRINGS-1);