摘要：T he Domain Name System (DNS) specifcation calls for the
use of caching. Caching is expected to improve the overall
responsiveness of the system by ensuring that answers to ques-
tions are known and stored locally and that the query load placed
on the authoritative servers is minimized. Certain presumptions are
associated with caches that may no longer hold. This article looks at
some of these presumptions and explores some of the problems that
emerge when they are violated. Based on our observations, we offer
some recommendations on DNS cache best practices and show our
results of testing these practices.
