Neighbor Solicitation messages are sent to discover the link-layer address of a neighbor or to verify that a neighbor is still reachable via a cachedlink-layer address.
传送“近邻请求”讯息是为了探索邻居的连结层位址，或是透过快取的连结层位址验证仍然可以与邻居连线。
2
When you follow a link to the cached copy, the search terms are marked.
如果链接到一个缓存的副本，搜索词就被加上标志。
3
The lookup stage caches the query result and performs the lookup operations on the cached order details based on the order IDs from the OrderID input link.