na_num
nat->in_nsrc.na_num = $2.n;
nat->in_ndst.na_num = $5.n;
PRINTF("%d", np->in_nsrc.na_num);
PRINTF("%s", base + np->in_nsrc.na_num);
PRINTF("%d", np->in_nsrc.na_num);
PRINTF("%s", base + np->in_ndst.na_num);
na->na_num,
base + na->na_num,
na->na_num,
base + na->na_num,