DNS解析順序和遞迴非遞迴查詢

順序為：

本地DNS緩衝

本地HOSTS檔案

DNS伺服器

在RFC1034 4.3.1中有這樣的描述：
•The simplest mode for the server isnon-recursive, since it can answer queries usingonly local information:
the response contains an error, the answer, or a referral to some other server"closer" to the answer.
All name servers must implement non-recursive queries.
•The simplest mode for the client is recursive, since in this mode the name server acts inthe role of a resolver
and returns either an error or the answer, but never referrals. This service isoptional in a name server, and
the name server may also choose to restrict the clients which can use recursivemode.b