rpl配置文件rpl_private.h

1. define uip_is_addr_linklocal_rplnodes_mcast

   定义本地广播地址，默认为ff02::001a;

2. RPL_CONF_DAO_LATENCY
   DAO回复延时，RPL_DAO_LATENCY默认为4S， 实际延时为：RPL_DAO_LATENCY/2 到1.5* ：RPL_DAO_LATENCY之间的随机数。
   注：某些特殊情况，DAO是立即回复的 dao_output(last_parent, RPL_ZERO_LIFETIME)

3. define DAO_EXPIRATION_TIMEOUT 60

   Expire DAOs from neighbors that do not respond in this time. (seconds)
   DAO回复超期时间

4. learned_from RPL路由来源
   Values that tell where a route came from

   define RPL_ROUTE_FROM_INTERNAL 0

   define RPL_ROUTE_FROM_UNICAST_DAO 1

   define RPL_ROUTE_FROM_MULTICAST_DAO 2

   define RPL_ROUTE_FROM_DIO 3

5.instance->mop = RPL_MOP_DEFAULT
/* DAG Mode of Operation */
#define RPL_MOP_NO_DOWNWARD_ROUTES 0
#define RPL_MOP_NON_STORING 1
#define RPL_MOP_STORING_NO_MULTICAST 2 //默认值
#define RPL_MOP_STORING_MULTICAST 3

6.#define RPL_DIS_INTERVAL 60
DIS 发送间隔 ，单位为S

7.#define RPL_DIS_START_DELAY 5
RPL_DIS_START_DELAY 上电启动延时
刚启动第1帧DIS的发送时间为 RPL_DIS_INTERVAL随机延时 - RPL_DIS_START_DELAY

void rpl_reset_periodic_timer(void)
{
  next_dis = RPL_DIS_INTERVAL / 2 +
((uint32_t)RPL_DIS_INTERVAL * (uint32_t)random_rand()) / RANDOM_RAND_MAX -
    RPL_DIS_START_DELAY;
 ctimer_set(&periodic_timer, CLOCK_SECOND, handle_periodic_timer, NULL);
}