EXPIRE_TIME
now_expire = EPOCH - EXPIRE_TIME;
now_expire = now.tv_sec - EXPIRE_TIME;
if (new->rts_time >= now.tv_sec - EXPIRE_TIME)
new->rts_time = now.tv_sec - EXPIRE_TIME;
if (now.tv_sec - RT->rt_time > EXPIRE_TIME) {
&& now.tv_sec - ifp->int_act_time > EXPIRE_TIME) {